# LAUE:Laue Back-Reflection of X-Rays

This experiment looks at crystal planes in a single crystal using a technique involving constructive interference of X-rays.

Max von Laue won the Nobel Prize in Physics in 1914. Other Nobel Prizes involving X-Ray crystallography include Lawrence Bragg and William Bragg (Physics 1915), Max Perutz and John Kendrew (Chemistry 1962), Dorothy Hodgkin (Chemistry 1964), and Venkatraman Ramakrishnan, Thomas Steitz, Ada Yonath (Chemistry 2009).

### Write-Up in PDF Format or Microsoft Word Format.

Appendices in PDF Format , Web Format

(The lab is currently located in MP226; last write-up revision: Aug. 2006.)

MATLAB file, useful for this lab: showLaue.m

This handy little code can be run on the Matlab command-line with the command: showLaue(NORMALPLANE,MAXINDEX,DIST,LP,LABELALL). It opens a new window, which projects a picture of Laue spots as if the user is the crystal looking at its reflection in the polaroid film with the incident radiation wavevector opposite to the specified plane normal NORMALPLANE = [h,k,l]. Spots are shown in all visible permutations of [-MAXINDEX:MAXINDEX]. Projection is made DIST units from crystal, DIST > 0. If LABELALL == 1, then all visible points are labelled with the corresponding plane. If LABELALL == 0, then only those visible points which belong to the form specified by LP = [h,k,l] are labelled. Disable labelling by setting LABELALL = 0 and LP = [0,0,0]. Axes are indicated on the image with coloured arrows: (x,y,z) = (red,green,blue). So, for example, to plot spots opposite to the plane normal [1,0,1] plus or minus 3, with projection distance of 12 cm, labeling only the [2,2,2] points, you would type: showLaue([1,0,1],3,12,[2,2,2],0)

X-Ray attenuation lengths can be found here

3rd year Engineering Sciences Nanotechnology Option student, Emina Veletanlic, working on the Laue Back-Reflection of X-rays (26 January 2005).

Last updated on 6 October 2011