1. Bunch by Bunch Profiling with a Rotating X-ray Mask
Christopher Lee
University of California – San Diego
Dr. Alan S. Fisher
Accelerator Systems Department at the Stanford Linear Accelerator Center

2. Introduction PEP II, bunches.
Why we want to monitor bunch cross sections?
How to monitor?
PEP II storage rings
Linear Accelerator
X-Rays

3. The Project $$$ Project Goal. Bunch statistics: Possible solution:
1700 bunches
4.2 nanoseconds
Possible solution:
$$$

4. Brightness vs Position
Proposed Solution
Measure properties and reconstruct.
Integrate brightness and plot.
Brightness vs Position

5. The Plan: X-Ray Mask Wheel

6. Setup
Three Slot X-Ray Mask
Beam Pipe
Scintillator
PMT

7. Change of Plans
Some obstacles: Scintillator, wheel design, encoder. Time.
Test concept with simpler setup.

8. Test Run Setup Blinking LED Two Slot Wheel 2 Slot Wheel Green LED
100 mm Lens
PMT

9. Test Run Setup
2 Slot Wheel
Lens
LED
PMT

10. Test Run Setup

11. .25 second

13. 7.3 microsecond

17. Results Center of wheel to LED image: 49.2 mm
Standard deviation: second
Full width at half maximum =
2.355*SD = second
Rotation rate: 2 Hz
Calculated diameter: *2*2*3.14*49.2 ~ 4.66 mm
Actual diameter: 6.35 mm

18. Acknowledgments SLACers Funding: Department of Energy SLAC
Mentor: Dr. Alan S. Fisher
Mechanical Engineering Consultant: Nicholas Reeck
SLACers