1. e+/e- Vertical Beam Size during CESR-c Collisions
E. Tanke, R. Holtzapple
Data taken 8/1/2006

2. e+ Average Vertical Beam Size:
Parasitic measurements made during CESR-c colliding beams.
The vertical distribution is averaged over 100 turns (10,000 turn total).
Fit each PMT profile to a Gaussian distribution to determine the sv(15.6 pixels/mm calibration).
Two separate data sets taken.
Typical 100 turn average e+ distribution. Note: Fit values shown here are in pixels not mm here

3. Average sv for two data sets.
100 turn pulse to pulse sv.
e+ vertical beam size decreases along each train (except for train 3)!

4. Mean position of vertical distribution for each train.
e+ vertical position increases along each train.
Correlation between sv and mean position of the vertical distribution.

5. Single bunch current
Slight correlation between beam size and current

6. e+ Single Turn Vertical Beam Size:
Single turn vertical distribution for 500 turns.
Typical single turn distribution
Vertical beam size for bunch 1 over 500 turns
Average single turn sv-Vertical beam size decreases along the train!

7. Single turn mean position along the trains
Single bunch mean position for bunch 1.

8. e- Average Vertical Beam Size::
The vertical distribution is averaged over 100 turns (10,000 turn total).
Fit each distribution to Gaussian to determine the vertical beam size (5.5 pixels/mm calibration)
Vertical beam size growth along each train (except for train 1)!
Average sv.
Typical distribution
100 turn pulse to pulse sv.

9. Current/bunch increases along each train (except for train 7).
Vertical position for each bunch along the train

10. e- Single Turn Vertical Beam Size:
Single turn vertical distribution for 500 turns.
Typical single turn distribution
Single turn vertical beam size for bunch 1 over 500 turns
Single turn mean position for bunch 1 over 500 turns

11. Summary
The positron sv decreases along the 3 bunch trains. In addition, the relative mean position of the distribution increases along the train which results in a correlation between sv and the mean vertical distribution.
The electron sv increases along the 3 bunch trains.
From the single turn analysis it is evident that the e- sv jitter (standard deviation) is ~3 time larger than the e+ sv jitter. The e- mean position jitter is ~2.5 times larger than the e+ mean position jitter.