1. Considerations on Beam Diagnostics Physics
Jilei Sun, Jingyu Tang (IHEP)
International Review Meeting on
C-ADS Accelerator Physics Design
September 19, 2011

2. Outline Introduction Consideration of major diagnostic devices
Beam diagnostics scheme for the first phase
Summary

3. Introduction Beam current 10mA Frequency 325MHz Duty factor 100%
Energy up to 1.5GeV
3.08 ns (325MHz)
Current 10mA

4. Aim
Commission the accelerator
Monitor and maintain normal operation
Protect the hardware
Provide information for trouble-shooting
Types
On-line
Characterization

5. Interesting properties
Energy
Intensity
Beam profile
Position
Emittance
Beam loss

6. Scheme of the C-ADS beam diagnostic systems

7. Consideration of major diagnostic devices
Beam Position Monitors (BPM)
Steer and center the beam in the aperture
Warm BPM (strip-line) and cold BPM (considered to be button type)

8. Beam Current Transformers (BCT)
Provide the transmission efficiency in the initial commissioning
Monitor the variation of beam current during the operation

9. Beam loss monitors (BLM)
Minimize the beam losses
Significant part in the MPS
Beam profile monitors (Wire Scanner)
Measures the emittance and envelopes
WS used in the commissioning with reduced beam power
Non-interceptive type

10. Beam phase monitors
BPM or Fast BCT (FCT)
Emittance measurement
Double-slit system in LEBT &MEBT
Multi-profile method for high energy
Collimators
LEBT, MEBT1 and MEBT2

11. Diagnostics-box
Modest power beam stop.
Double-slit emittance measurement system.

12. Existing devices

13. Beam diagnostics scheme for the first phase
At the moment, only the injector diagnostics has been designed.
For the MEBT1-1

14. Parameters of the diagnostic devices for the MEBT1
Quantity
z-extent(mm)
Measures
Accuracy
Response
Beam Position
Monitors (BPM) 6
<90
Position/
Phase
<±0.1mm ——
Fast Current
Transformer (FCT) 2
<50
current
<0.1mA
<50ns
Beam Loss
Monitors (BLM) 3
beam loss
<1%
<2us
Wire Scanner（WS）
<60
x/y profile
<0.1mm
Emittance 1
Transverse
emittance
<2%
Beam stop

15. For the 3~5MeV
Cold BPM (considered to be button type).
D-box with beam stop and double-slit emittance measurement system.

16. Summary
BPM, BLM, FCT, BLM, D-box…will be used in the C-ADS diagnostic systems.
Some prototypes are exist in IHEP.
The scheme of the diagnostic system for the first phase has been finished.

17. Thanks for your attention!