# Presentation: 037892

## First Polarization Measurements30 Jan 2008

## Target scan in Blue

- Seen beam loss with target moving in. Decide to swtich from target 5 to 1 as there may be a problem on the beam position here.

## First attempt: Bad pattern

- First attempt of polarization measurement at yellow injection: -5.8+-2.6% This is with 13 bunches and wrong spin pattern (+-+- filled, ++-- desired). We will refill and try again.

## Better Pattern

- Yellow injection polarization: -29.2+-2.6%. The sign is off since we filled kind of as toggle.

## Banana

## T-Dependence

## Spin Pattern

## Polarization Vector

## Blue target1 scan. It caused quite beam loss. Center moved by 3mm from yesterday.

- Blue Target 1 scan

## Orbits

- Orbits from yesterday and today.

## Moving down linearly by two mm. Not good.

- Moved Blue Target down 2mm

## Movin up by 2mm this time the loss is almost nothing. 

- Moved up 2mm

## moving up another 1.5mm and loss is worse. I will move it back down. 

- Move up 1.5mm more

## Fresh Beam

## The blue polarimeter get very little carbon events. First we have to find out why there are so many non-carbon events. The target scan also generates a lot beam loss.

## After Vincent fixed the horizotnal orbit, Another try with target1. I still see large beam loss.

## Target 5 Scan

## lienar position 36500 

## linear position 38500.

## linear 40500 

## linear 34500. 

## linear 38000,

-  this seems the best for now.

## Target 3 at 74000 

## V target4 peak at 148543. 

## v target6 peaked at 148128.

-  The linear position would
-  cause beam loss.
- But it is close to the limit switch.

## V target6 with linearly higher by 500 counts. still large beam loss. 

## H target1 scan. It shows that emittance is large.

## fresh beam with h target1. still large emittance reported.

## Target3 gives similar odd shape beam profile but target clearance is good. 

## H target2 is seen. 

## raise linear by 1mm helped to reduce beam loss.

## See more beam loss with linear position at 64000. 

## Another try with h target2.

## H target4. 

- Beam is back
-  to Gaussian now.

## Slide 35

## Fresh beam
with h target1. 
Non-gaussian beam.

- with h target1.
- Non-gaussian beam.

## Just to satisfy 
our curiosity, 
we run the h 
target4 again 
with the fresh
bean 

- our curiosity,
- we run the h
- target4 again
- with the fresh
- bean

## Blue polarization measurement with horizontal target 1. The value should be analyzed later when corrected deadlayer 

## The spin pattern is as expected. 

- The spin pattern is as expected.

## Target scan after cut parameter set to carbons.

## Target scan with broad range. 

## Another measurement with vertical target1.

## Banana shape and spin pattern look correct.

##  23:32 Summary of Polarimeter commissioning tonight:
1. We scanned all blue targets. A few targets always cause beam loss when inserted. It could be related to the large transverse emittance and possibly the misaligned target frames (the targets were aligned properly in the expense of the crooked target frames). For some targets, the linear positions are near the positive limit switches. To use these target at injection, we need ring access to raise the limit switches.
2. Both rings were filled with toggle mode. Polarimeter detected correct spin pattern in this mode. remaining to be seen is the filling with a desired spin pattern.
3. The cut parameters have been adjusted so that carbon bananas are in the right places. There is still need to do dead-layer correction to get meaningful polarizaiton values. Some si strips requires individual tweaks. 
Haixin,Anatoli,Ron

- 1. We scanned all blue targets. A few targets always cause beam loss when inserted. It could be related to the large transverse emittance and possibly the misaligned target frames (the targets were aligned properly in the expense of the crooked target frames). For some targets, the linear positions are near the positive limit switches. To use these target at injection, we need ring access to raise the limit switches.
- 2. Both rings were filled with toggle mode. Polarimeter detected correct spin pattern in this mode. remaining to be seen is the filling with a desired spin pattern.
- 3. The cut parameters have been adjusted so that carbon bananas are in the right places. There is still need to do dead-layer correction to get meaningful polarizaiton values. Some si strips requires individual tweaks.
- Haixin,Anatoli,Ron