1. Future Work Plan and Action Items
Jim Clarke
ASTeC & Cockcroft Institute
Daresbury Laboratory
16/7/10
DESY Positron Workshop

2. Actions from DESY Workshop
Actions were placed on many groups at the DESY Workshop (Jul 2010)
Short Term (Dec 2010)
Medium Term (Mar 2011)
Longer Term (end 2011)
General comments/outstanding items
Positron Workshop

3. Undulator
Continue “Real” Undulator spectrums modelling of multiple 2m undulators – David
Impact of random angular errors inside undulators – spot size on target, polarisation loss? Include quad misalignment – ANL
Complete 4m cryomodule & test (fix heat load problem!) – RAL
Horizontal magnet measurements required at some stage???
Electron beam tests required at some stage
Modules need to be engineered for large scale production and operation
Intermodule connections need engineering
Store cryomodule safely so can be powered at a later date 3

4. Source Modelling
Use real spectrum in PPS-Sim – Mike/Ian (assistance from DESY?)
Generate lattice for source to DR - ?
Supply period vs K for Nb3Sn undulator – RAL
Assess impact of Nb3Sn undulator - Wei
Look at PTRAN losses in ANL simulations with new lattice – Wei
Ongoing list of current simulation codes and objectives + input files – Ian
Ongoing yield/polarisation evaluation with source design evolution (Wei) 4

5. Compton
Continue DR stacking studies and work with DR group to ensure optimum solution - Frank
cavity stability tests (LAL/KEK) - Omori
Laser demonstration – Fabian Zomer, Vitaly
ATF demo with 4 mirror system – Omori
2010/11 demo with new cavities of high gamma flux at ATF 5

6. Polarisation
Polarisation change with collimator aperture/beam position jitter (0.5 sigma jitter in electron position and angle) - ANL
Close contact with IP group polarimeter (Tony)
Ensure spin survives to DR
Close contact with simulations group – spin track to IP
Confirm investigation showing we can destroy polarisation in DR completely
Electron spin survival within undulator – Des
Study performance of spin rotator design, jitter effects etc (5GeV) 6

7. Collimation High power photon collimator needs to be studied
Positron collimation – design documented, needs updating as source evolves
Variable aperture collimator needed for polarisation upgrade
(Electron collimation before undulator – BDS group?) 7

8. Target Complete Eddy current tests at Daresbury – Ian
Store target properly – Ian/Jim
Generate simulations to compare with experimental results – (Jeff/Tom) Ian/RAL
Measuring conductivity of target material - Mike
Pressure shock wave analysis – Stephan to pass on all files to Ian/Sabine (wiki) and write up/document and numerical modelling later
Energy compression before DR to be studied to improve yield – Wan Ming
Vacuum seal & water union tests – LLNL
Ferrofluid radiation tests
Beam tests on Ti (also W) samples (~100J/g) – ANL/LLNL/DESY/Ian to check what beam is suitable and make appropriate proposal (also 250 GeV beam collimators)
Lifetime studies of target (LLNL)
Alternative liquid metal & window (BINP/KEK tests) – Junji
Engineered solution, including prototype tests – water, vacuum, … 8

9. OMD
Li Lens - Cornell
Evaluate level of radiation damage in window & implications for lifetime
Stress-strain in window with liquid flow
Thermal cycling fatigue
Cavitation wear on windows
Proton beam tests?
Assess KEKB BN window tests - Omori
Discuss funding with M Harrison – Marc/Nick
Concern with liquid li containment in steel (Pavel)
Flux Concentrator
Complete design – LLNL
Build prototype 9

10. Remote Handling RH scenarios refined
Changeover times (requirement ties in with lifetime of kit in RH)
Replacement of pillow seals?
Pillow seals need R&D
Need engineered design compatible with source layout (remove inconsistencies!)
If yield increases then RH not needed (limited only?)
Use detailed target, RF, etc model in Fluka 10

11. EDMS work package Report back on EDMS status – ongoing action Ian/Lars
Put instructions on the wiki - Ian
Use the wiki instead! 11

12. Auxiliary Source Is electron beam dump ok for AS?
How to separate electron drive beam?
Where do particles get lost?
Intensity requirements vs BPM resolution
How many bunches are needed ?
Nick says Aim for 5% intensity 12

13. 10 Hz Source Check cooling system of target – LLNL/ANL
Put holes in target to let unwanted gamma beam through? Assess other options?
Generate consistent layout showing extra electron dump, drive beam line to dump etc

14. Thanks to Gudi and Sabine for organising this workshop
Thanks to you all for participating!