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.

• 25 Feb 2008 First compilation of beam hits

-- NigelWatson - 23 Feb 2008

• Megarun 1: