Bent Crystal Results to Date Feb 26, 2007 D. Still

Relative Positions of Crystal and E03H

Thought from Discussions Is there an effect on baking the strip crystal. Is there an effect on baking the strip crystal. Should we request addition crystals for possible use here. Maybe 150urad and ~400 urad. Should we request addition crystals for possible use here. Maybe 150urad and ~400 urad.

Total Work on Sat Finished scans Finished scans Scanned -28 mils point. Scanned -28 mils point. Data w/ TEL off Data w/ TEL off Data w/ 1mm bump Data w/ 1mm bump

Effect of TEL off TEL off drops losses by X2. TEL off drops losses by X2. Not sure if this is a problem. Not sure if this is a problem.

Results of scan from 20 to 46 mils

Results of a 3urad scan from a 36x36 end of store study

Channel Signature

Rescan of possible channel (-28mils)

Could not Confirm Channeling Should have seen channeling but only saw large losses. Maybe due to beam motion, angle does Not repeat? Beam on Feb 20 different than Previous store. Crystal and E03H Did not go in as far. Previous EOS FEB 20 EOS

Summary of the Crystal Studies: Completed a 2 urad step size scan over the entire range of the ~ 8000 urad of the inchworm. In part of that data on Feb 19 saw a signature of channeling. Completed a 2 urad step size scan over the entire range of the ~ 8000 urad of the inchworm. In part of that data on Feb 19 saw a signature of channeling. Rescanned the area that was believed to be channeling (E0CCIW ` -28 mils) multiple times including different rates, inch worm approaches and a +1 mm vertical offset to the crystal. We could not reproduce any other signature of channeling. Rescanned the area that was believed to be channeling (E0CCIW ` -28 mils) multiple times including different rates, inch worm approaches and a +1 mm vertical offset to the crystal. We could not reproduce any other signature of channeling.

Summary continued Did make a scan with TEL 2 off and noticed that it reduced the amount of loss noise on the crystal by about a factor of 2. This should not effect channeling. Also TEL was used during “O” shaped measurements without problem only addition of noise. Did make a scan with TEL 2 off and noticed that it reduced the amount of loss noise on the crystal by about a factor of 2. This should not effect channeling. Also TEL was used during “O” shaped measurements without problem only addition of noise. Todd informed that the optical offset measured before installation was 0 = 3.9 volts on the LVDT which is about 2000 urad offset. There should still be a enough inchworm angle to see channeling. Todd informed that the optical offset measured before installation was 0 = 3.9 volts on the LVDT which is about 2000 urad offset. There should still be a enough inchworm angle to see channeling. Attempts to make a horizontal angle bump would only lead to a small angle and we are not sure that alignment is the total problem. Attempts to make a horizontal angle bump would only lead to a small angle and we are not sure that alignment is the total problem. This leaves making the bend angle and alignment measurements in the tunnel as the next best ideas. This leaves making the bend angle and alignment measurements in the tunnel as the next best ideas.

The Plan this Week: Finish scanning the 8 mrad angular range of inchworm. Investigate anything that looked like channeling. 8 mrad Angular Inchworm range This is the signature we are looking for Scanned last week Scanned this week

Looking for the channel