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SENRef User's Guide - BonPhysics Research and Investigations BV

1. or This panel defines the Qx cuts by means of 6 input boxes and 1 selection box Number of cuts input box This number represents the number of cuts in the figure Each Qx value is represented by one line in the graph Selected Cut input box This number indicates from which Qx cut the values are indicated in the two lower input boxes Ox avg input box This number gives the average Qx value of the cuts When equal to 0 the lowest Input box of the current panel is changed to Delta Angle unit milliradians when different from 0 the lowest Input box is Ox width unit micrometer Delta Angle input box This number determines the angle difference of the scattered angle between which the intensities are added to find the specular cut unit milliradians Ox width input box This number determines the intervals used to add the intensities for the specific Qx cut unit micrometer Min Wavelength input box This number determines the minimum of the wavelength range used to calculate the cuts for the specific Qx cut Max Wavelength input box This number determines the maximum of the wavelength range used to calculate the cuts for the specific Qx cut 24 4 2009 page 27 SENRef User s Guide Enable Ox Cut selection box This indicates weather or not the selected cut should be plotted and fitted or not Qx Cuts Generator panel Qx Cuts Generator Ox first order um 1 10 827 Qx Width of cuts um 1
2. Sample surface scattering function eq 6 124 of reference in footnote 2 si 3 ARo p p een O Je S pfe 2 k ARo nl 2x fetes FEER Jer Ami 9 EIS f Or 2 aet Jeep 24 4 2009 page 49 SENRef User s Guide Phase Object Gaussian Random Distribution standard deviation o average A complex constant q E em e FT na E Dee 9 OM C z a A R uls An Min ceo o s d Sample surface correlation function G 5 E z G K e G re p k r E Go k Roo p BOG Cag 1 Roo p p Sample surface scattering function S p k O A Roo p p ple Se P k A Ro k p p es f e 9i eo cn 1 dr 24 4 2009 page 50 SENRef User s Guide Phase Object Block Height H Period L Width D el E ere 1 ge 1 0 lt x lt D E Dauer 1 len o Hl 1 D lt x lt E E 15 cos 4 H 1 Sample surface correlation function STEEN 22 gd ia ni 2 0 lt x lt D GYS 3 k 7 G k Rolkop cos q H 1 ul aS 2 Roo P gt P L L PO y y D lt x lt Gore 5 k 7 Go k Ree cosa 1 2 Ryo p p Sample surface scattering function s amp 5 Q AR p p P 1 22 12 eost se p E AR k P p35 0 2 1 cos q H u sin na x Nc B Dre na ei n 00 n 0 nz 24 4 2009 page 51 SENRef User s Guide Phase Object Block Gaussian Distributed Height H Period L Width
3. 0 0553 Number of Positive Orders 9 Number of Negative Orders 2 Include Specular The selection box four input boxes and button on this panel can be used to generate the Qx cuts Qx first order input box This number determines the Qx average value of the first order cut used to add the intensities for the specific Qx cut unit micrometer Ox width input box This number determines the Qx interval width used to add the intensities for the specific Qx cut unit micrometer Number of Positive orders Input box This number represents the number of Qx cuts with a positive order All cuts for 1 to the indicated number are generated Number of Negative orders Input box This number represents the number of Qx cuts with a negative order All cuts for 1 to the indicated number are generated Include specular selection box If the selection box is checked the generated Qx cuts will include the specular one For the width of the specular one the resolution of the incident angle is taken see Instrument Window Instrument Panel Resolution input box Generate button Pressing this button generates the Qx cuts The generated Qx cuts can be checked in the graph on the Sample Window and QxQyPlot window 24 4 2009 page 28 SENRef User s Guide Calculate Qx Cuts panel Calculate Ox Cuts Scale Factor 0 67 1013 w Polarization Cor Cae Data None Calculate Lessel The input boxes and button
4. 7 L L L L Vom _ 4p TK v 2H mfr Dans G2 B k 7 CS 3 2 2e reel H Re x J 1 6 Sample surface scattering function 2 TERES E TT 1 H OEZ 2 8 Q EG 8z p y ffe Deal et el e M cos H Re x 1 x Sp 5 E A 3 4 Ix 2 sin ne x KS B O D 52 n 0 n 0 nz i 24 4 2009 page 47 SENRef User s Guide DWBA Block Gaussian Distributed Height H Period L Width D E enw eT iua mV co f H 7 r ik H 5 dE el o C 7 E also ei 0 lt x lt D es m 2 EI DSx lt 5 cm 2 o url L E Sample surface correlation function 2 Gr tz Gow p L 1X D em 4 P y P PE m 4p T Kk Refoje h e eG Gpe Bk GO 3 y I o MUS e y i 1 5j m T p alg Bae py 0 lt x lt D GoM Bk F GO p 4p F k vc el L EUR Dt 4p T at ue a d K DiseL 6 UA E HJE GO p Sample surface scattering function 2 fere y 2 eigtl Ell eet y 2nz D Hs do sin 205 7 D Buet 1 H f ME 408 2007 el DE n o 2 m le nz 24 4 2009 page 48 SENRef User s Guide Phase Object General Sample surface correlation function Fourier transform of eq 6 124 of reference in footnote 2 2 PB Roo ky p 2 zo y k p gt De Ge D A Rro EE SCH a 5 en e e mp Ge Ltr zs Go x peel ler e m PO y y
5. D E enw e FT ina E ge UG nn e D lt x lt c s m 2 cti url L L cl D x D 0 lt x lt D Gone tz Go x E ook D L 2 L fpe T samt Ryo K p o q LE Dese Jg 2 k 7 G UNES Dle W1 Sample surface scattering function B p k s O AR p p pe X Spee P e AR 2 i D malo EN a DN Pug ys EECH er n 00 ES qi 2nz 2nz 24 4 2009 page 32 SENRef User s Guide Born Approximation Similar to Phase Object Approximation except that R k p is replaced by I RAR sje zc x Ss 4p3 p k 24 4 2009 page 53 SENRef User s Guide 2 D sample surface correlation function According to Sinha for a reflectometer geometry no angular resolution in the direction perpendicular to the beam and parallel to the sample surface here the z direction the scattered intensity is given by the integral over O this was implicitly assumed in the previous but there the sample surface correlation function was either in the z or x direction The resulting intensity is then given by the Fourier integral over the Q of the sample surface correlation function for z 0 DWBA General Sample surface scattering function which only holds if sn 5 k is integrated over Q S p k feng 2 67 a r SO Le lena A y S p K 42 Fe 0 8z p Soe p k AT Zeil few Cul ES 276 Q ix H F gi ez u According to eq 7 1
6. Me Aw BE J Oo 2zxl q 2 jz in 2 e o while the specular part remains unchanged 24 4 2009 page 56
7. X2 D2 Xm Dm Where indicates start of file indicates end of line indicates end of file indicates user required repetition of sequence YO is a number Not used Y1 is a number Not used Xj j 1 m Distance Profile mode or wavelength Polarization mode in nm Dj Data values for Xj Height in nm Profile mode or Polarization 24 4 2009 page 43 SENRef User s Guide Appendix C Background of performed calculations In general the calculations are done using the equations described in chapter 6 of the reference of footnote 2 To speed up the calculations it was assumed that the incident mutual coherence function on the sample position was homogeneous and Gaussian distributed with a large coherence length in the beam direction and a small one in the direction perpendicular to it The coherence length is the standard deviation of the Gaussian distribution In principle the spin echo signal for a grating must be determined using eqs 7 14 and 7 15 of reference in footnote 2 However if there is only structure in the z direction and the in plane angle is 0 then eq 7 24 can be used to speed up the calculations If some in plane angle different from 0 is used in principle this is wrong for the scattering in the x direction Then the Number per Coherence length parameter must be increased to find the correct spin echo signal for the scattering In the following the basic equations for the several
8. changes to the one for the Wavelength The first input box changes from Spin Echo Constant in Time Of Flight mode into Footprint Angle in monochromatic mode In Time of Flight mode the 3 panel from the top changes to the Wavelength Range panel In monochromatic mode it changes to the Incident Angle Range panel Check box Spin Echo In Time of Flight mode it is possible to indicate weather the measurements are made with Spin Echo or without Without Spin Echo only the non polarized scattered intensity can be calculated or loaded saved With Spin Echo the plus and minus scattered intensity can be calculated or loaded saved As an extra in the Spin Echo mode the polarisation and the shim intensity can be shown Further the input box Spin Echo Constant and the Load button will be enabled Input box Spin Echo Constant In Time Of Flight mode the spin echo constant is used The input must be changed to the desired value and depends on the setting of the apparatus The value represents the spin echo length in micrometers divided by the square of the wavelength of the neutrons in nanometres Input box Footprint Angle In Monochromatic mode the spin echo constant is not used but the footprint angle is important The value represents the incident angle at which the incident beam just covers the sample length in the direction of the beam For larger incident angles the beam footprint is reduced with the ratio sin Footprint angle sin Incident angl
9. fitted are the cuts defined and enabled on the QxCuts and QyCuts Windows The program only calculated the point needed to determine these cuts Lesser cuts and the smaller ranges increase the fit speed The fit is based on the minimization of the so called chi squared i e The average quadrate of the difference between fit and data point divided by the error The minimization procedure is based on the Marquardt Levenberg method This method calculates the steepest decent from the matrix inversion of the Jacobian matrix If a change in a fit parameter has no influence or very small on the calculated chi squared the possibility exist that the inversion of the Jacobian matrix is singular and the fit does not converge to the local minimum This is indicated by the Matrix inversion indicator turning to red The window has three control panels Select Fit Parameters Define Fit Parameters and Fit Control and a results panel Fit Results and a button Reset Fit Reset Fit button Pressing this button initialized the model parameters The start values are taken from the Instrument and Sample Windows 24 4 2009 page 34 SENRef User s Guide Select Fit Parameters panel Select Fit Parameters lt InstrumentD ata Incident Angle Resolution InstrumentD ata Incident Angle SampleD ata G amma SampleD ata 5 ample Period SampleD ata 5 ample Base Dutycycle E InstrumentD ata Incident Angle Resolution 0 078 Add Fit P
10. predefined sample surface types can be selected An 1D or 2D surface type is described by a height profile An isotropic sample surface type is defined by a Gaussian correlation function The formula used depends on the selected approximation and is given in Appendix C The profile or correlation can be predetermined or user defined Capillary Waves selection The Gaussian roughness correlation function is given by C r al ed jJ where O is the roughness and the correlation length See also the reference in footnote 3 The value for rai is a cut off value r 2 a N where N value of input box Number of points per correlation length a value of input box Integration range in correlation length Gravitational Waves selection The Gaussian roughness correlation function is given by C r 0 K r E a where O is the roughness the correlation length and K the modified Bessel function of zero the order See also the reference in footnote 3 The value for r 0 is cut off for K a 1 a 0 45689248915903589527 Self affine fractional selection The Gaussian roughness correlation function is given by 2 2h C r 0 et where O is the roughness the correlation length and h the so called jaggedness parameter See also the reference in footnote 3 24 4 2009 page 15 SENRef User s Guide Self affine fract anal selection Similar to Self affine fractional but calculated analytically following the method
11. 005 Visual Basic and will need the NET Framework This will all ready be installed on your computer installed at set up or you should provide it yourself When the program is started a splash screen will pop up showing a disclaimer you have to accept before the program continues Region I Disclaimer Altough great care was used to ensure the correct algorithms are used it is possible calculated data contains deviations from expected outcome By pressing the Accept button the user acknowledges this and agrees that he she takes full responsibility for interpreting the results Copyright TU Del 2009 Version1 1 Push the Accept button if you agree that the use of the program is at your own risk and no rights or claims can be derived from using the program If this button is pressed the program continues searching in the resources sub directory of the directory where the program is stored for a XML formatted file that contains the default settings If the program can not locate the file in this directory the user is prompted by a file input dialog box typical for the operating system to indicate where the file can be found The user can select a session data file or press the CANCEL button If this button is pressed the program issues a warning indicating that no session data file was loaded SENRef Warning Default Session Data file Not Loaded 24 4 2009 page 5 SENRef User s Guide After pressing the OK button th
12. 4 of reference in footnote 2 the 2 shim count rate is proportional to this Sample surface scattering function integrated over the source area detector area and sample area The 2 flip count rate can be found in a similar way using eq 7 16 where Pz in the ideal case eq 7 8 Pr 0 is cos Q 1 hence Tier AT Sch E C amp Q d e E eee Joi H 5 J dx IN 2 6 Q while the specular part remains unchanged Similar expression can be derived for the Phase Object and Born Approximations 2 Sinha et al Phys Rev B 38 4 1988 p2297 2312 24 4 2009 page 54 SENRef User s Guide Appendix D Self Affine Gaussian correlation function and its Fourier transform The Self Affine Gaussian correlation function is defined as gt E E EE Cs ore gt where o standard deviation of distribution h is the jaggedness parameter and is the correlation or cut off length The expectation value of such a distribution is given by 0 7 C4 F gt E jen 7 7 Hs4 The specular part of the scattering can be calculated from the standard deviation alone according to the formulas in Appendix C The off specular part is proportional to the Fourier transform of eg sal where Q x for DWBA and O q for Born approximation and Phase object approximation According to R Pynn Phys Rev B Vol 45 No 2 January 1992 p602 612 As long as q 0 lt 1 areasonable ap
13. Define Type G Neutrons Time of flight gt Non Polarized Neutrons Time of flight Neutrons Monochromatic Polarized Neutrons Monochromatic O X rays Up Spin X rays Angle mrad Down Spin X ray wavelength nm 35000 Including Error From File 0 1540 El Including Error From File or This panel is used to select the type of data that is loaded with the selected file The data file is very simple not containing this information Initially the values are copied from the Instrument Window To the left side the panel consists of selection type buttons comparable with the ones used in the Instrument panel and an input box for the incident angle or wavelength depending on the selected measurement type To the right side one can select which data is included in the selected file The format of the input file is defined in appendix A If the selection box Polarized is checked the selection box Swap is enabled The box interchanges the plus and min intensity inverting the resulting polarization 24 4 2009 page 1l SENRef User s Guide If the selection box Include Error is checked the selection box From File will be enabled If both selection boxes are checked the program expects the data to contain the errors according to the format of appendix A If the selection box From File is not checked but Including Error is the program assumes that the data in the file are raw neutron counts and the error is calculated as the square
14. Measurent Scaling Factor InstrumentD ata Measurent Scaling Factor SampleD ata 5 ample Height SampleD ata 5 ample Height Value Value Spread Spread Spread Spread 056407531 Correlation 0 0005203 Matrix Inversion Indicator The two selection boxes and three buttons on this panel can be used to investigate the fit results and copy the values to the initial fit values The output boxes show information on the fit parameters selected in the selection boxes above The Spread output boxes are calculated using the co variance matrix determined from the Jacobian matrix It is an indication of the accuracy of the selected fit parameter The Correlation output box is the correlation between the selected fit parameters Copy to Start Value button If pressed the actual value of the selected fit parameter is copied to its initial value This enables the continuation of the fit with the end value of the previous fit 24 4 2009 page 38 SENRef User s Guide Copy All to Start Value button If pressed the actual value of all fit parameters are copied to their initial value This enables the continuation of the previous fit 24 4 2009 page 39 SENRef User s Guide 10 Thanks Window SENRef Instrument Sample REESEN QxCuts QyCuts Fitting Thanks Make Session Default SENRefSessionData xml i SENRef Sample Region I Region II Detector This program has been written by Vic
15. NRef User s Guide Data panel Data ConvertedD ata87 osv Orders in color scale 5 3 Scales from Data 10 Log This panel consists of one input box one output box and two selection boxes The input box Is a number to change the logarithmic colour scale of the graphs The output box is only visible when a data file has been loaded and shows the name of the data file The selection boxes are the Scales from Data selection box and the 70 Log selection box Scales from Data selection box If selected checked the calculation scales are the same as the data scales If not selected the calculation scales are as defined on the Instrument Window 10 Log selection box If selected checked the colour plot scale is logarithmic with base 10 If not selected the scale is linear Save button This button enables the data output If pressed a file selection dialog will pop up requesting a filename Extensions are OUT for a space delimited file OSV for a TAB delimited file or CSV for a comma delimited file If a valid filename is chosen the data will be saved under that name The format of the file is the same as of the input file see Appendix A but errors will not be included Load button This button enables the data input If pressed a file selection dialog will pop up requesting a filename Extensions are OUT for a space delimited file OSV for a TAB delimited file or CSV for a comma delimited file If a valid fil
16. Pm2 Mm2 Plm Mimi Xm 1 24 4 2009 page 41 SENRef User s Guide Polarized With Errors XY0 YT YJ YL YL X2 Y2 YN YO us Yn Yn Yn Yn Yn l Yn 1 X1 P11 EP11 M11 EMII P12 EP12 M12 EMI2 Pin EPIn Min EMIn X2 P21 EP21 M21 EM21 P22 EP22 M22 EM22 P2n EP2n M2n EM2n Xm Pml Em Mm EMml Pm2 EPm2 Mm EMm2 Pmn EPmn Mmn EMmn Xm 1 Where indicates start of file indicates end of line indicates end of file indicates user required repetition of sequence YO is a number Not used Yi i 1 n start values of scattered angle interval i In ascending order Yi 1 1 1 n end values of scattered angle interval i In ascending order Xj J 1 m start value of incident angle Monochromatic mode or wavelength TOF mode interval j In ascending order Xj 1 G 1 m end value of incident angle Monochromatic mode or wavelength TOF mode interval j In ascending order Dij Data values for Xj Yi Eij Error in data values for Xj Yi standard deviation Pij Data values Up Spin for Xj Yi EPij Error in data values Up Spin for Xj Yi standard deviation My Data values Down Spin for Xj Yi EMij Error in data values Down Spin for Xj Yi standard deviation 24 4 2009 page 42 SENRef User s Guide Appendix B Format of Data file 1 Dimensional Profile and Empty beam polarization The files are simple ASCII files The input format is as follows YO Y1 Xl DI
17. Rough Gaussian Dist and Gauss Envel and 9 input boxes SA Rough Check box If checked the scattering is convoluted with the scattering determined by a Self Affine roughness as defined by the sotropic Data panel The values taken for the Self Affine roughness distribution are taken from that data Gauss Envelop check box If checked the sample correlation function is multiplied by a Gaussian envelop function with a correlation length given by the input box Correlation length This mimics a not perfect periodicity or represents an artificial resolution contribution The formula used is where r is the correlation distance and r the correlation length Gauss Dist check box If checked the sample is described by a height profile function The correlation function is calculated assuming the grating is not perfect periodic but has a Gaussian correlated distribution The formula used depends on the selected approximation and is given in Appendix C The height profile function can be predetermined or user defined This is determined by the Grating data panel 24 4 2009 page 19 SENRef User s Guide Correlation length input box This value determines correlation length of the sample correlation function in nanometers It is only enabled when the Gauss Envelop selection box is selected Gamma Layer input box This value represents the scattering length density of the sample layer material times 4n in nanometer units Height Inpu
18. SENRef User s Guide Region I Region II Detector TOP VIEW V O de Haan April 2009 SENRef User s Guide Contents Ts TAO A O sua a kS Q pasanqa Ee 3 Die CARL pr gtaM EE 5 3 Instrument ee 2 nd nu tO esc EE 7 4 Import Measurement Window atate tenente eee ea a e Y rti Re Rp NE es 11 5 Sample Windows n Rice Seca lade neg Ee asya 14 6 QXQyPlot WIdOW xl ala ss 24 Ty OXCUES NI ra ue trt um n usc qiu ut bd 26 8 QyC ts WNdOW TER 30 9 Eating E A ON 34 TO Thanks WIBCO daisies anan u IN u een a t a ua uuu Sas 40 Appendix A Format of Data file ia 41 Appendix B Format ef Data Tesis dalla dlls 43 Appendix C Background of performed calculatons cono nonnncnnns 44 Appendix D Self Affine Gaussian correlation function and its Fourier transform 55 24 4 2009 page 2 SENRef User s Guide 1 Introduction The acronym SENRef represents the words Spin Echo Neutron Reflection Hence the program was designed to interpret these kinds of measurements Such measurements can be performed either in Time of Flight TOF mode or in monochromatic mode In TOF mode the incident angle is fixed and in general a position sensitive detector PSD is used as a neutron counting device The wavelength 2 of the neutrons is determined by the time it takes for the neutron after passing the chopper to reach the detector In this time slot the neutrons will have interacted with the sample surface either by refraction specular refl
19. arameter The selection box input box and button on this panel can be used to select the fit parameter Selection box The selection box shows all possible parameters which can be fitted for the instrument and sample model chosen Selecting a parameter will change the vale of the input box under the selection box The name of the parameter will appear in the output box Input box This value is the initial value of the selected fit parameter Add Fit Parameter button If this button is pressed the parameter is removed from the above mentioned selection box and moved to the selection box in the Define Fit Parameters panel This parameter will now be fitted 24 4 2009 page 35 SENRef User s Guide Define Fit Parameters panel Define Fit Parameters InstrumentD ata Measurent Scaling Factor SampleD ata S ample Trapezium Slope i Min Value 0 1 Start Value 80 Max Value 49900 Copy All to Model The selection box three input boxes and three buttons on this panel can be used to set the right upper and lower limits of the fit parameters The smaller the range the faster and reliable the algorithm will find the desired minimum Selection box The selection box shows all parameters are fitted Selecting a parameter will change the vale of the input boxes under the selection box Min Value input box This value determines the lower limit of the fit parameter selected in the sele
20. ate the cuts for the specific Qy cut Max Wavelength input box This number determines the maximum of the wavelength range used to calculate the cuts for the specific Qy cut Enable Qy Cut selection box This indicates weather or not the selected cut should be plotted and fitted or not 24 4 2009 page 31 SENRef User s Guide Qy Cuts Generator panel Qy Cuts Generator Oy first order nm 1 0 066 y Width of cuts nm 1 0 0044 Number of Orders 5 Generate The three input boxes and button on this panel can be used to generate the Qy cuts v Oy first order input box This number determines the Qy average value used for the specific Qy cut unit nanometer 1 Default value is determined by the height of the sample Oy width input box This number determines the Qy interval width used to add the intensities for the specific Qy cut unit nanometer 1 Default value is determined by the height of the sample Number of orders input box This number represents the number of Qy cuts All cuts for 1 to the indicated number are generated Generate button Pressing this button generates the Qy cuts The generated Qy cuts can be checked in the graph on the Sample Window and QxQyPlot window Calculate Qy Cuts panel Calculate Qy Cuts Scale Factor 0 67 10 3 Polarization Cor Cale Data None Calculate p The input boxes and buttons on this panel can be used to re calculate the Qy cu
21. ction box Start Value input box This value determines the initial value of the fit parameter selected in the selection box Max Value input box This value determines the upper limit of the fit parameter selected in the selection box 24 4 2009 page 36 SENRef User s Guide Remove button If this button is pressed the parameter is removed from the above mentioned selection box and returned to the selection box in the Select Fit Parameters panel This parameter will is not fitted anymore Copy to model button If this button is pressed the actual value of the parameter selected in the above selection box is copied to the parameter in the Instrument or Sample Window The previous value of this parameters is lost Copy All to model button If this button is pressed the actual value of all possible fit parameters in the both selection boxes of the Select and Define Fit Parameter Panels are copied to the respective parameters in the Instrument or Sample Window The previous values of these parameters are lost Control Fit panel Fit Control Maximum number of iterations 100 2 10 LOG Iteration accuracy lt 3 3 Added Acc to data Abs Rel La Pia Pia Bi fe B2 Bo Bo Bo P La D bo d C HSM 0 2 4 6 3 i0 12 Iteration number The four input boxes and two buttons on this panel can be used to control the fitting procedure The graph at the lower side of the panel shows the chi squared as funct
22. described by R Pynn Phys Rev B Vol 45 No 2 January 1992 p602 612 See also appendix D Output box The output box just below the Load button shows the filename of the loaded profile if present other wise the output box is empty If a user defined height profile or correlation is selected the button Load is enabled Load button This button enables the profile input Note that for a 1D or 2D user defined profile the height distribution is loaded and for an isotropic defined profile the correlation function If pressed a file selection dialog will pop up requesting a filename Extensions are OUT for a space delimited file OSV for a TAB delimited file or CSV for a comma delimited file The format of the input file is defined in appendix B If a valid filename is chosen another window will pop up enabling the correct data input This window is called Import Data File Window Import Data File Window Import Data File 600 800 1000 Along Beam Direction nm Name of Dataset Imported Profile i C Documents and Settings Victor de Haan Bureaublad a out 24 4 2009 page 16 SENRef User s Guide At the upper part of the window the data is shown as loaded To the lower left the window has one panel Name of Dataset This panel contains an input box for the name of the dataset It can be used for future reference Below this panel an output box shows the filename of the imported data To the lower right it c
23. e If a valid filename is chosen the data will be saved under that name 24 4 2009 page 29 SENRef User s Guide 8 QyCuts Window SENRef Instrument Sample QxQyPlot QxCuts GyCuts Fitting Thanks Load Session Save Session Make Session Default Qy Cuts Definition Number of cuts 5 3 Log Shim Intensity A U Selected cut 2 Qy avg nm 1 0 066 Con Qy width nm 1 0 0044 Min Wavelength nm 0 101 Max Wavelength nm 0 991 Qy Cuts Generator Qy first order nm 1 0 066 Qy Width of cuts nm 1 0 0044 Number of Orders 5 2 Y Generate Calculate Qy Cuts Scale Factor 067 103 Polarization Cor Calc Data None 1 y 1 d Em di v 10LogScale Orders in log scale 5 3 The purpose of this window is for diagnostic purposes only Be sure that the data calculated matches the required parameters hence calculation is the last action performed on the Sample Window To the left side this window has three panels The Oy Cuts Definition panel the Oy cuts Generator panel and the Calculate Oy Cuts panel At the left bottom side it has a selection box 10 Log Scale and an input box Orders in log scale and to the right an output graph showing the cuts The cuts represent both the data if available as error bars and or the calculations if available as lines The corresponding Qy cuts have the same colour The intensities are j
24. e and the intensity with the square of this ratio The input must be changed to the desired value and depends on the setting of the apparatus Input boxes Incident Angle or Wavelength Resolution and Coherence length These inputs must be changed to the desired values The Incident Angle is the angle between incident beam and sample surface The resolution is the standard deviation of the Gaussian distributed Incident Angle spread of the beam The coherence length is the width of a homogeneous Gaussian distributed mutual coherence function As the three variables are coupled see chapter 6 1 1 of reference in footnote 2 changing one will result in a corresponding change of the others For SENRef the relation between these parameters is _ 4 1000 27 a Aa F where r is the Coherence Length in micrometer units 2 the wavelength in nanometer d the Incident Angle in milliradians and Aq is the Resolution also in milliradians 24 4 2009 page 8 SENRef User s Guide Load button This button enables the empty beam polarization input If pressed a file selection dialog will pop up requesting a filename Extensions are OUT for a space delimited file OSV for a TAB delimited file or CSV for a comma delimited file The format of the input file is defined in appendix B If a valid filename is chosen another window will pop up enabling the correct data input This window is called Jmport Data File Window See also the Load Button
25. e button enable the data output If pressed a file selection dialog will pop up requesting a filename Extensions are OUT for a space delimited file OSV for a TAB delimited file or CSV for a comma delimited file If a valid filename is chosen the data will be saved under that name Orders in colour scale input box The input box is a number to change the logarithmic colour scale of the graphs 10 Log Scale selection box If selected the output of the shown graph have a logarithmic scale 24 4 2009 page 25 SENRef User s Guide 7 QxCuts Window SENRef Instrument Sample QxQyPlot QxCuts GyCuts Fitting Thanks Load Session Save Session Make Session Default Qx Cuts Definition Number of cuts 3 Log Intensity U Selected cut 2 Qx avg um ue E Ox width um 0 0968 Min Wavelength nm 0 101 Max Wavelength nm 0 991 Qx Cuts Generator Qx first order um 1 0 827 Qx Width of cuts um 1 0 0553 Number of Positive Orders 0 E Number of Negative Orders 2 v Include Specular d II Calculate Qx Cuts i E fi il UE en Hi sa gl Calculate I 1 10LogScale Orders in log scale 6 Warelengi nm The purpose of this window is for diagnostic purposes only Be sure that the data calculated matches the required parameters hence calculation is the last action performed on the Sample Window To the left side this windo
26. e program continuous with the default values of the program The above SENRef Warning dialog box will appear whenever the user does something unexpected For all parameters tooltips are given explaining shortly the use of the control that is pointed at with the mouse The program has a button driven interface which consists of 1 tab control with 7 major tab windows Instrument Sample OxOyPlot OxCuts and QyCuts Fitting and Thanks and three buttons Load Session Save Session and Make Session Default Load Session button This button enables the session data input If pressed a file selection dialog will pop up requesting a filename The used extension is XML as the session data file is XML formatted If a valid filename is chosen the session data file will be loaded enabling the continuation of a previous session Save Session button This button enables the session data output If pressed a file selection dialog will pop up requesting a filename The used extension is XML as the session data file is XML formatted If a valid filename is chosen the session data file will be saved enabling the continuation in a future session Make Session Default button This button enables the creation of a default session data file If pressed the session data is saved in the default session data file that will be automatically loaded at the next start of the program Clicking the names of the tab windows will select that window The Instrument Wind
27. ection or off specular reflection In monochromatic mode the wavelength of the neutrons is fixed to some small interval and the incident angle is varied The angle after interaction with the sample can be determined either by a PSD or by a slit in front of a single detector The definition of the sample geometry is given in figure 1 Figure 1 Definition of angles in spin echo neutron reflection geometry a is the angle between the path of the incident neutron represented by vector k indicated by the green arrow or the red arrow where the start of the vector has been shifted to the sample surface and the sample surface fy is the angle the path of the incident neutron makes with the xy plane a the angle between the path of the off specular scattered neutron vector p and the sample surface and p is the angle between the path of the off specular scattered neutron and the xy plane 0 is the angle between the path of the off specular scattered neutron and the path of the not scattered neutron In general the wave vectors are given by cos a cos Z cos a cos sin a p sin z cos a sin cos a sin 24 4 2009 page 3 SENRef User s Guide Throughout the program the small angle approximation for the determination of the wave vectors is used hence He BY 1 4 a 4 8 gt 27 _ 2x SEH s p 2 f B The neutron beam of a reflectometer is always collimated in two directions The first directi
28. ed The larger the number the more accurate and slower the calculations 24 4 2009 page 21 SENRef User s Guide Calculation Data panel Calculation Data Number per coherence length 1 i Number of points per Angle Div 1 Phase Object e LE I This panel defines the theory used to perform the scattering calculations and some parameters needed to perform the calculations The panel contains 2 input boxes and 3 selection boxes Number per Coherence length input box for 1D profile This number determines the number of orders used to calculate the scattering for a periodic structure It corresponds to the range of n in the summations of Appendix C In general if the separate Qx cuts can be distinguished in the scattering then this parameter can be 1 If they start to overlap this number must be increased If they coincide due to scattering in the z direction only to get an accurate result the number must be taken large enough A rule of thumb for an X profile Number of points Coherence length Period Coherence length Cos In Plane Angle the Cos function changes into a Sin function for an Z profile It is wavelength dependent as the coherence length is wavelength dependent The calculations are slower if the number is larger Number per Coherence length input box for 2D profile This number determines the number of intervals used to calculate the Fourier transform of the 2D correlation function d
29. ed matches the last calculation action performed on the Sample Window The QxQy plot is calculated in such a way that the integral over O O of the scattering function gives the same value as the integral over 4 dp To the left side this window has two panels The Ox Range panel and the Qy Range panel To the right side it has a selection box 70 Log Scale and an input box Orders in colour scale and two output graphs showing the plots for the calculations and the data At the bottom of the window three buttons appear the Calculate button and two Save buttons Qx Range panel Ox Range Minimum um 1 2 5 Maximum um 1 05 Number 300 This panel consists of three input boxes Minimum Maximum and Number and a button Default They define the linear range and step over which Qx is varied Note that the unit of Qx is micrometer Pushing the default button changes the values to the range available in the calculations Qy Range panel Qy Range Minimum nm 1 i0 Maximum nm 1 0 3 Number 150 4 24 4 2009 page 24 SENRef User s Guide This panel consists of three input boxes Minimum Maximum and Number and a button Default They define the linear range and step over which Qy is varied Note that the unit of Qy is nanometer Pushing the default button changes the values to the range available in the calculations Calculate button This button starts the calculations It can take a while before it finishes Save buttons Thes
30. ename is chosen another window will pop up enabling the correct data input This window is called Import Measurement Window 24 4 2009 page 10 SENRef User s Guide 4 Import Measurement Window Import Measurement Define Type Neutrons Time of flight Non Polarized Neutrons Monochromatic Polarized O X rays Up Spin Angle mrad Down Spin 3 5000 4 Including Error From File Name of Measurement Dataset BR 8 SSeS sc Imported Data 16 03 E pci 7 nm Wavelength Range and Resolution Reflected Angle Range and Resolution Data Input nm O A Input Deg G mrad Min value s d Angle Offset mad q Minimum nm Resolution type Minimum mrad Resolution type Maximum nm Maximum mrad D Mijn i A documenten BonPhysics Projecten Number Gaussian Number G Gaussian TUD R3 Measurements ISIS_No Resolution width Resolution width v2007 ConvertedD ata87 osv Relative Relative 2 Absolute im 00000 Absolute mad 0 0000 To the upper left the window has two panels Define Type and Name of Measurement Dataset To the upper right there is space for two graphs showing the selected input data At the bottom there are three panels Wavelength Range and Resolution or Incident Angle Range and Resolution Scattered Angle Range and Resolution and Data Finally at the right bottom of the window there are two buttons OK and Cancel Define Type panel Define Type
31. ength Range or Incident Angle Range and Data panel To the right there is space for viewing the data after loading Depending on the status of the instrument panel and the data loaded graphs are given of the relevant neutron or X ray intensity plots At the bottom there are two buttons Load and Save Instrument panel Time Of Flight mode Monochromatic mode Instrument Instrument Time DFFlight Time Of Flight Monochromatic Neutron Monochromatic Neutron O Ray Ray C Spin Echo Spin Ech Empty beam polarization Empty beam polarization Spin Echo Constant c Footprint Angle ET micrometer nm 2 ass mrad 386 Incident Angle mrad 3 5 Wavelength nm 0 154 Resolution mrad 10 078 Coherence length um FS at 0 154 nm 3 5 mrad 83 77971 Resolution mrad 0 078 Coherence length um at 0 154 nm 3 5 mrad 89 798 The instrument panel consists of three selection boxes for the measurement type and a check box for the Spin Echo mode four input boxes Spin Echo Constant or Footprint angle Incident Angle or Wavelength Resolution and Coherence length and a Load and Show button 24 4 2009 page 7 SENRef User s Guide Selection boxes measurement type Select either Time of Flight only for neutron scattering Monochromatic Neutron or Monochromatic X Ray In Time of Flight mode the second input box on the instrument panel changes to the input box for the Incident Angle In monochromatic mode it
32. etermined from the user defined height profile function The Fourier transform extends to 5 times the coherence length Number of points per Angle Div input box This number determines the number of intervals used to calculate the influence of the width of the interval of the scattered angle channels Selection box This selection enables the selection of the theory used for the calculations Options are First Born approximation Phase Object approximation Distorted Wave Born approximation see Appendix C for detail or Extended Phase Object approximation see Thanks Window click on picture below text The Extended Phase Object approximation is not implemented for the Gaussian distribution of the profile s For this approximation one can either choose the height to be constant or the scattering length density of the layer to be constant by selecting the appropriate radio button after the Height input box or Gamma Layer input box For this approximation it is also possible to have a different scattering length density for the substrate and the layer Note that the colour of the DWBA selection box turns red if the calculations render an unrealistic result due to the imaginary part of the wave vector transfer becoming too 24 4 2009 page 22 SENRef User s Guide large negative Then the criteria for the DWBA are not fulfilled Roughly the criteria are small disturbances less then a few nanometer in height only close to the critical edge o
33. heory G Average Gamma Gamma substrate nm 2 0 0026 Grating Data SA Rough Gauss Dist v Gauss Envel Correlation length nm 30000 Gamma Layer nm 2 Height nm Const 97 7 Period nm E DutyCycle Base 23 7 Slope Z 100 In Plane Angle deg 83 3 Divergence In Plane Angle deg 0 2 Number of points per In Plane Angle 5 3 Calculation Data Number per coherence length 1 06 03 Wavelength nm Number of points per Angle Div 110 phase Dhea Orders in color scale 5 Y 10 Log Scale To the left side this window has four panels Sample Surface Type Specular Data Grating Data or Isotropic Data or nothing and Calculation Data To the right side it has a selection box Type two output graphs two buttons Calculate and Save an input box Orders in colour scale and a selection box 0 Log Scale The panel Grating Data appears if a 1D or 2D profile is selected The panel Isotropic Data appears if an Isotropic profile is selected Sample Surface Type panel Sample Surface Type None Load 1D Block 1D Trapezium This panel defines the type of profile or correlation function describing the sample From this function the scattering is calculated according to the approximation selected in the Calculation Data panel The panel has one selection box and two buttons and an output box 24 4 2009 page 14 SENRef User s Guide Selection box Several
34. imum Maximum and Number define the range and number of data points in the data file Relative and Absolute 24 4 2009 page 12 SENRef User s Guide define the resolution distribution not used for now The button Swap at the upper top side is used to swap the data in the file so that the axes are interchanged Data panel Data Min value s d Angle Offset mrad d DAMin documenten BonPhysics Projecten TUDS RAS Measurements ISIS_No 2007 ConvertedD ata87 osv This panel consists of two input boxes and an output box The output box shows part of the data file name The input box Min value is enabled if the Including Error box was selected in the Define Type panel If the relative error of the data point is larger than the value in this box the error is set to 0 The input box Angle Offset is used to shift the incident angle scale over the value given in the box OK button This button copies the data to the main program and returns the control to the Instrument Window Cancel button This button ignores the data and returns the control to the Instrument Window 24 4 2009 page 13 SENRef User s Guide 5 Sample Window SENRef Instrument Sample QxQyPlot OxCuts QyCuts Fiting Thanks Load Session Save Session Make Session Default SENRefSessionData xml Sample Surface Type None A Load Ea 3 Calculation Data rapezium Reflected Angle mrad Reflected Angle mrad Specular Data O T
35. ion of the iteration number Maximum number of iterations input box This number determines the maximum number of iterations The fit can stop sooner if the required accuracy in chi squared is reached 10 LOG Iteration accuracy input box This number determines fit accuracy It is used as a measure of the step size to determine the gradient of the function and it determines the minimum change in chi squared to continue fitting 24 4 2009 page 37 SENRef User s Guide Abs input box This value is added to the error of each cut point value to manipulate the fitting For instance it can be used to overcome faulty error bars due to wrong background subtraction Rel input box This value is the percentage of the cut point value that is added to the error of each cut point value to manipulate the fitting For instance it can be used to overcome faulty error bars due to wrong scaling Start button Enables the start of the fit procedure All input boxes or buttons on all windows are disabled It is possible to change to another Window during the fit to investigate its progress on either the Sample QxCuts or QyCuts Windows Stop button If pressed the fit is stopped after the current iteration is finished The start button can be pressed again and de fit will restart Fit Results panel Fit Results Number of iterations Chi 2 Copy all to Start Values SampleD ata 5 ample Period InstrumentD ata
36. ion range in 5 v correlation length This panel defines the isotropic correlation functions describing the sample Either by means of a predefined or by a user defined correlation function It consists of 5 input boxes describing the correlation function sample Roughness Correlation Length and Jaggedness Correlation Length input box This parameter defines the correlation length of the sample surface Roughness Input box This parameter defines the Gaussian roughness of the sample surface Jaggedness input box Only enabled for a Self affine fractional correlation function This parameter defines the type of Gaussian roughness correlation function A small value produces an extreme jagged surface and a value of 1 gives smooth hills and valleys It is related to a fractal surface with fractal dimension 3 Jaggedness See also the reference in footnote 3 Number of points per correlation length input box Determines the number of points used to calculate the correlation function The larger the number the more accurate and slower the calculations Integration range in correlation length input box Determines the maximum range over which the correlation function extends in units of correlation lengths The larger the range the more accurate the results for small momentem tranfer and the less accurate the results for large moment transfer These can also be more accurate when the number of points per correlation length is increas
37. on parallel to the sample surface is in general very wide and the second direction perpendicular to the surface is in general small some mm to 1 10 of mm The latter slit width is important for the resulting profile resolution and determines also the coherence length of the neutron beam along the sample surface The former slit width is kept wide to keep the beam intensity as high as possible as the reflected intensity will be orders of magnitude smaller than the incident intensity as much as 6 to 8 orders have been achieved The Spin Echo technique can be used to code a component of the direction of an individual neutron in the beam and find out the component of the scattering angle in the same direction If this direction is used along the wide slit direction then also the scattering angle parallel to the sample can be determined yielding information on the sample surface in all directions The information obtained in the direction parallel to the surface are the sample surface correlation functions and perpendicular to the surface the sample profile J Plomp Spin echo development for a time of flight neutron reflectometer Thesis Delft University of Technology 2009 2 V O de Haan Coherence approach to neutron propagation in spin echo instruments 1 ed BonPhysics Research and Investigations B V 2007 24 4 2009 page 4 SENRef User s Guide 2 Start program The program is written in Microsoft Visual Studio 2
38. on the Grating Data panel on the Sample Window Show button The Show button enables investigation of the loaded empty beam polarization If this button is pressed a window will pop up showing the data This window is called Show Data Window See also the Load Profile Button on the Sample Window Reflected Angle Range panel Reflected Angle Range Minimum mrad Maximum mrad 20 Number 50 4 This panel consists of three input boxes Minimum Maximum and Number They define the linear range and step over which the reflected angle is varied This range will be used for the calculations if the Scales from Data selection box is not checked Incident Angle Range panel Available when in Monochromatic Mode Incident Angle Range Minimum mrad 0 Maximum mrad 20 Number 50 This panel consists of three input boxes Minimum Maximum and Number They define the linear range and step over which the incident angle is varied This range will be used for the calculations if the Scales from Data selection box is not checked Wavelength Range panel Available when in Time Of Flight Mode Wavelength Range Minimum nm 0 1 Maximum nm Number 50 s i This panel consists of three input boxes Minimum Maximum and Number They define the linear range and step over which the wavelength is varied This range will be used for the calculations if the Scales from Data selection box is not checked 24 4 2009 page 9 SE
39. ontains three buttons Swap button This is used to swap the data in the file so that the axes are interchanged OK button This button copies the data to the main program and returns the control to the Instrument Window Cancel button This button ignores the data and returns the control to the Instrument Window Show button This button presents the used profile If this button is pressed a window will pop up showing the profile as it is defined This window is called Show Data Show Data 1000 300 Along Grating nm Type of Data At the upper part of the window the defined profile is shown To the lower left the window has one panel Type of Data This panel contains an output box indicating the type of data To the lower right it contains two buttons 24 4 2009 page 17 SENRef User s Guide Save button This is used to save the data into a file Extensions are OUT for a space delimited file OSV for a TAB delimited file or CSV for a comma delimited file If a valid filename is chosen the data will be saved under that name The format of the file is the same as of the input file see Appendix B OK button This button returns the control to the Instrument Window Specular Data panel Specular Data Specular Data Theory Average Gamma Theor Average Gamma Gamma substrate nm 2 Gamma substrate nm 2 at wavelength nm 0 0026 0 0253 0 154 DS or This panel defines the sam
40. ow is used to define the instrument parameters and load the measured data The Sample Window is used to define the sample parameters load sample profiles and perform calculations The QxQyPlot QxCuts and QyCuts windows are used for diagnostic purposes and defining the cuts These windows work for either or both the loaded data including the calculation of the error bars for QxCuts and QyCuts and the calculated data The Fitting window can be used to fit the selected sample model to the data The Thanks windows contains clickable images yielding information about the program and theory behind the calculations used 24 4 2009 page 6 SENRef User s Guide 3 Instrument Window SENRef Instrument Sample QxQyPlot QxCuts GyCuts Fitting Thanks Load Session Save Session Make Session Default SENRefSessionData xml Instrument Time Of Flight Intensity Monochromatic Neutron Reflected Angle mrad O XRay C Spin Echo Empty beam polarization Spin Echo Constant micrometer nm 2 Incident angle mrad 353 Resolution mrad 10 075 Coherence length um at 0 154 nm 3 5 mrad 92 7998 Reflected Angle Range Minimum mrad Maximum mrad Number Wavelength Range Minimum nm Maximum nm Number Data ConvertedD ata87 osv Wavelength nm i Orders in color scale v Scales from Data To the left the Instrument Window has 4 panels Instrument Reflected Angle Range Wavel
41. ple surface and the way the specular part of the reflectivity is calculated It consists of two selection boxes Theory and Average Gamma and one or two in X Ray mode input box es Gamma substrate and at wavelength Theory selection box If selected the specular part is calculated from the theory provided by the selected approximation The formula used is given in Appendix C Average Gamma selection box If selected the specular part is calculated from the scattering length density profile determined by the surface average of the height profile function Gamma substrate input box This value represents the scattering length density of the sample substrate material times 4n in nanometer units at wavelength input box In X Ray mode this value represents the wavelength corresponding to the value given for the scattering length density of the sample material in the Gamma input box 24 4 2009 page 18 SENRef User s Guide Grating Data panel Grating Data C SA Rough _ Gauss Dist Gauss Envel Correlation length nm 30000 Gamma Layer nm 2 Height nm 97 7 Period nm 900 DutyCycle Base 23 7 Slope E In Plane Angle deg 83 3 Divergence In Plane Angle deg 0 2 Number of points per In Plane Angle 5 2 This panel defines the height profile function describing the sample Either by means of a predefined or a user defined height profile function The panel has three check boxes SA
42. proximation of this value is found by inserting cola h c ash ze Di e 2 009 1 ae S where a Qo c a h and c a h are parameters which depend only weakly on a but strong on h and c a h depends weakly on h and stronger on a Pynn does not give values for these coefficients but it can be found that a reasonable approximation is given by 4 e c a h TS eo alan a Bl 11 KO EH p max Zar e 24 4 2009 page 55 SENRef User s Guide where o is the coherence length defined as the standard deviation of the Gaussian Resolution distribution of the neutron or X ray beam I x I i Ocon J 270 The Fourier transform of this approximate function is a Voight function which can be calculated by means of the complex error function However it can also be approximated by a sum of a weighted Lorentzian and Gaussian distribution with different width The way this is done is shown by P Thomson et al J Appl Cryst 20 1987 p79 83 and G K Wertheim et al Rev Sci Ins 45 11 1974 p1369 1371 cos q x 1 jer SI o 8 E parelen EA eal n Te na se Mle o N 20T iu 2 3 T 2 T5 2 69269L T7 2 42843T T7 4 471631 51 0 07842 IT I 2 r 3 L 0 47719 0 11116 r r T 2 ln 2 16 Lo 16 c a h The 2 flip count rate can be found in a similar way where the approximation is used S where n l 366031 star e 7 Ja Ia glor Msc
43. r far away from the critical edge Type selection box With this box the type of data shown in selected Chose Shim Plus intensity Min intensity or Polarization Calculate button This button starts the calculations It can take a while before it finishes The bar directly to the right indicates progress made During calculations the Save button changes into a Stop button that can be used for obvious reasons After stopping in this way the data the calculated is not reliable Save button This button enables the data output If pressed a file selection dialog will pop up requesting a filename Extensions are OUT for a space delimited file OSV for a TAB delimited file or CSV for a comma delimited file If a valid filename is chosen the data will be saved under that name Orders in colour scale input box The input box is a number to change the logarithmic colour scale of the graphs 10 Log Scale selection box If selected the output of the shown graph has a logarithmic scale 24 4 2009 page 23 SENRef User s Guide 6 QxQyPlot Window SENRef Instrument Sample OxQyPlot Gscuts QyCuts Fitting Thanks Save Session Make Session Default Ox Range Minimum um 1 Calculation Maximum um Number Du Range Minimum nm 1 Maximum nm 1 Number Orders in color scale 7 10 Log Scale m The purpose of this window is for diagnostic purposes only The data calculat
44. root of the counts If selection box Including Error is not checked all errors are set to 0 Name of Measurement Dataset panel Name of Measurement Dataset Imported Data This panel contains an input box for the name of the loaded dataset It can be used for future reference Wavelength or Incident Angle Range and Resolution panel Wavelength Range and Resolution Incident Angle Range and Resolution Input mO A Input Deg mrad Minimum nm Resolution type Minimum Z mrad 17 Resolution type Maximum nm Maximum mrad File Number Gaussian Number Gaussian Resolution width Resolution width Block Relative Relative Absolute nm 0 0000 Absolute mrad 0 0000 s or This panel contains 2 selection criteria Input nm or A and Resolution type File Gaussian and Block three output and two input boxes Minimum Maximum and Number define the range and number of data points in the data file Relative and Absolute define the resolution distribution not used for now Scattered Angle Range and Resolution panel Reflected Angle Range and Resolution Input Deg mrad Minimum mrad Resolution type Maximum mrad Number Gaussian Resolution width Relative Absolute mrad 0 0000 This panel contains 2 selection criteria Input Degrees or milliradians and Resolution type File Gaussian and Block three output and two input boxes Min
45. s on this panel can be used to re calculate the Qx cuts and save them Scale Factor input boxes This factor is used to change the scaling factor of the measurements The calculations correspond to the number of neutrons or X rays counted in the detector channel except for a scaling factor For comparison the scaling of the measurements can be adapted to match the one of the calculations Polarization Correction selection buttons These buttons are visible if the polarization of the empty beam has been loaded using the Load button on the Instrument panel on the Instrument Window If Calc is selected the calculated polarization is multiplied by the loaded empty beam polarization If the wavelength is outside the available wavelength range the calculated polarization is set to 0 If Data is selected the measured polarization is divided by the loaded empty beam polarization If the wavelength is outside the available wavelength range the measured polarization is set to 0 If None is selected no correction is done Remember to use the Calculate button to let the changed selection take effect Calculate button Pressing this button re calculates the Qx cuts The Qx cuts can be checked in the graph to the right Save button This button enables the data output If pressed a file selection dialog will pop up requesting a filename Extensions are OUT for a space delimited file OSV for a TAB delimited file or CSV for a comma delimited fil
46. sample types and approximations are given 24 4 2009 page 44 SENRef User s Guide DWBA General Sample surface correlation function Combination of eqs 6 96 to 6 99 of reference in footnote 2 2 2 ITT go p AR p m A Fe y Sample surface scattering function Combination of eqs 6 104 to 6 107 of reference in footnote 2 S p k fea Ltr d r eelere 1 y S p k 4 A Fe 5 47 80 Q Spee p k E AT T p T k poema Ele J 24 4 2009 page 45 SENRef User s Guide DWBA Gaussian Random Distribution standard deviation o average u complex constant q E ier e T ling E C _ ca so 02 2 ce 2 H 5s H 5 7 d rs C0 e S Sample surface correlation function 2 Gir Ltr Go p Le ert Si y G Sy ss Ke Ap T k Re x Jo ect GA JE Gen y y y y D zj Pe UD AA ENS W s SCH e Sample surface scattering function 2 1 Py ca 1 a 5 6 Py 24 4 2009 page 46 SENRef User s Guide DWBA Block Height H Period L Width D Bee ler 1 jee dai Ce 1 i qz mls E 2 l a a Sc H 77 zm D lt x lt E ene 1 C cos H Ref _ 1 Sample surface correlation function jg ieee al GP p 75 GP p L tze SE gt 2 T k 0 lt x lt D Gy p k d Go 2 Ap T sl E42 Jem cos H Refx 1 e 7 lx
47. t box This value determines the sample height in nanometers If a height profile function is loaded it represents the total height of the loaded profile Period Input box This value determines the sample repetition period in nanometers If a height profile function is loaded it represents the repetition period of the loaded profile DutyCycle Base Input box This value determines the sample base width of either block or trapezium in of the period value Slope Input box This value determines the slope in of the trapezium 100 is an angle of 45 degrees The minimum angle depends on the height of the sample the period and the dutycycle of the base In Plane Angle Input box This value determines the orientation angle of the sample profile with respect to the beam For 0 the grating profile is parallel to the beam direction and for 90 it is perpendicular Divergence In Plane Angle input box This value determines the spread in the In Plane Angle parameter The distribution function is a block with a constant width and amplitude given by this value Number of points per In Plane Angle input box This number determines the number of interval steps used to calculate the influence of the divergence of the In Plane Angle parameter 24 4 2009 page 20 SENRef User s Guide Isotropic Data panel Isotropic Data Correlation Lenath nm 1 Roughness nm 1 Jaggedness Number of points per correlation length 50 Y Integat
48. tor de Haan BonPhysics BV for Delft University of Technology The theoretical background has been published in a book U D e ft Extended Phase Object Natuurkundig Onderzovks en Ontwiktelingsbureon A D BonPhysics Research and Investigations B V Click on the images to find out The purpose of this window is for information purposes only You can find this guide by clicking on the upper left picture The theoretical background for the calculations can be found in the book Coherence approach to neutron propagation in spin echo instruments This is opened if the lower left picture is clicked Clicking on the Extended Phase Object gives information about these calculations Clicking the right pictures opens the home pages of the corresponding institutes 24 4 2009 page 40 SENRef User s Guide Appendix A Format of Data file The files are simple ASCII files The input format is as follows Up Spin or Down Spin or Non Polarized Without Errors YO Yl Y2 Yn Yn 1 XI DII D12 D1n X2 D21 D22 D2n Xm Dm Dm2 Dmn Xm 1 Up Spin or Down Spin or Non Polarized With Errors XO YT Y1 Y2 Y2 Yn Yn Yn Yn 1 X1 DII E11 DI2 E12 Din Eln X2 D21 E21 D22 E22 D2n E2n Xm Dm Em1 Dm2 Em2 Dmn Emn Xm 1 Polarized Without Errors YO Yl Yl Y2 Y2 Yn Yn Yn 1 Yn 1 X1 P11 M11 P12 MI2 PIn MIn X1 P21 M21 P22 M22 P2n M2n Xm Pml Mml
49. ts and save them Scale Factor input boxes This factor is used to change the scaling factor of the measurements The calculations correspond to the number of neutrons or X rays counted in the detector channel except for a scaling factor For comparison the scaling of the measurements can be adapted to match the one of the calculations 24 4 2009 page 32 SENRef User s Guide Polarization Correction selection buttons These buttons are visible if the polarization of the empty beam has been loaded using the Load button on the Instrument panel on the Instrument Window If Calc is selected the calculated polarization is multiplied by the loaded empty beam polarization If the wavelength is outside the available wavelength range the calculated polarization is set to 0 If Data is selected the measured polarization is divided by the loaded empty beam polarization If the wavelength is outside the available wavelength range the measured polarization is set to 0 If None is selected no correction is done Remember to use the Calculate button to let the changed selection take effect Calculate button Pressing this button re calculates the Qy cuts The Qy cuts can be checked in the graph to the right Save button This button enables the data output If pressed a file selection dialog will pop up requesting a filename Extensions are OUT for a space delimited file OSV for a TAB delimited file or CSV for a comma delimited file If a
50. ust the sum of all of the intensities of the points between the upper and lower limits of the Qy cut defined by Qy max Qy avg Qy width and Qy min Qy avg Qy width The Qy cut summation areas if any are selected will be shown as black lines on the graphs on the Sample Window and QxQyPlot Window Orders in colour scale input box The input box is a number to change the logarithmic colour scale of the graphs 10 Log Scale selection box If selected the output of the shown graph have a logarithmic scale 24 4 2009 page 30 SENRef User s Guide Qy Cuts Definition panel y Cuts Definition Number of cuts 5 E Selected cut 1 t Du avg nm 1 10 066 ELEG Oy width nm 1 0 0044 Min Wavelength nm 010 Max Wavelength nm 391 This panel defines the Qy cuts by means of 6 input boxes and 1 selection box Number of cuts input box This number represents the number of cuts in the figure Each Qy value is represented by one line in the graph Selected Cut input box This number indicates from which Qy cut the values are indicated in the two lower input boxes Qy avg input box This number determines the value of the average Qy value the cuts should unit nanometer 1 Oy width input box This number determines the intervals used to add the intensities for the specific Qy cut unit nanometer 1 Min Wavelength input box This number determines the minimum of the wavelength range used to calcul
51. valid filename is chosen the data will be saved under that name 24 4 2009 page 33 SENRef User s Guide 9 Fitting Window SENRef Instrument Sample OxQyPlot QsCuts QyCuts Fitting Thanks Load Session Save Session Make Session Default Define Fit Parameters Fit Control SampleData S ample Period Maximum number of iterations 100 a InstrumentData Measurent Scaling Factor 10 LOG Iteration accuracy lt 0 3 2 Select Fit P SampleD ata S ample Height L RA See Added Acc to data Abs 0 Rel 0 InstrumentD ata Incident Angle Resolution InstrumentD ata Incident Angle SampleData Gamma SampleData 5 ample Base Dutycycle SampleData S ample Trapezium Slope BEES fS DO DO DO BO DS n DRK O Q5 CS ho A ch lo o 12 qetanoinunber 20 Fit Results Number of iterations Chi2 Copy all to Start Values lt SampleD ata S ample Period SampleData Sample Period 5 InstrumentD ata Measurent Scaling Factor JEE Min Value 0 01 SampleD ata S ample Height SampleData 5 ample Height ik Start Value 0 66 I Value Value nstrumentData Incident Angle Resolution Max Value 100 i ES S a Spread Tm Spread 4 7293742 Start EH Remove Copy to Model Spread 0 Value Spread Add Fit Parameter Copy Alto Model Correlation Matrix Inversion Indicator The purpose of this window is for fitting the model to the data The data
52. w has three panels The Ox Cuts Definition panel the Ox cuts Generator panel and the Calculate Ox Cuts panel To the left bottom side it has a selection box 10 Log Scale and an input box Orders in log scale and to the right an output graph showing the cuts The cuts represent both the data if available as error bars and or the calculations if available as lines The corresponding Qx cuts have the same colour The intensities are just the sum of all of the intensities in the points between the upper and lower limits of the Qx cut defined by Qx max Qx avg Qx width and Qx min Qx avg Qx width If Qx is equal to 0 the cut is the specular one between Incident Angle Delta Angle and Incident Angle Delta Angle The Qx cut summation areas if any are selected will be shown as black lines on the graphs on the Sample Window and QxQyPlot Window Orders in colour scale input box The input box is a number to change the logarithmic colour scale of the graphs 10 Log Scale selection box If selected the output of the shown graph have a logarithmic scale 24 4 2009 page 26 SENRef User s Guide Qx Cuts Definition panel Qx Cuts Definition Qx Cuts Definition Number of cuts 3 s Number of cuts 3 2 Selected cut 1 E Selected cut 3 i Ox avg um 1 63 Zen Ox avg um 0 Sein Qx width um 1 0 0968 Delta Angle 1 Min Wavelength nm 0101 Min Wavelength nm 015 Max Wavelength nm nom 7 Max Wavelength nm 05 i

SENRef User's Guide - BonPhysics Research and Investigations BV

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