Measurement of the sample surfaces can be done at KEK (at least for sample #1) and also in the UK (at Begbroke Science Park?). Measurement of damage at KEK is using Keyence VK8510 optical/laser microscope, assume comparable facility at Begbroke. Advantages to using optical microscope and interferometer rather than SEM alone.

Watanabe-san (yuichi.watanabe@kekNOSPAMPLEASE.jp) in the workshop made example images made on 21 Feb for sample #2 at two different magnifications:

1. x200
2. x2000
3. x2000, with vertical cross-section of Ra
4. x2000, 3D profile

Field of view and magnifications available at KEK workshop are as in the following table:

Mark analysed BPM measurements from Luis' Mega Sample: the 120 hits from one such run are extracted into this text file as (x,y) pairs. Plots showing the transverse distribution of the hits are shown below. Using a field of view of 400x400 um would be more than sufficient to search for the damaged regions initially. In the following, the coordinate system has (x,y)=(0,0)=lower left corner of sample as viewed from upstream,

• 25 Feb 2008 First compilation of beam hits

-- NigelWatson - 23 Feb 2008

/twiki/pub/ILCBDSColl/DamageDataAnalysis/megarun_fig1.tiff

• 

• 

• 
• 
• 
• 
• 
• 
• 
• 
• 

These were made with simple Matlab script roi.m which plots regions of interest (defined by pixel indices in ASCII text file from Mark) and Mathworks contributed file ellipse.m. Regions of interest input by hand as pulse numbers by inspection.

• megarun_fig1.tiff: megarun_fig1.tiff