1. G5 Design Review, April 24, 2009 Gun to 5cell Cavity Test: Overview Dmitry Kayran G5 test Design Review April, 24 2009

2. G5 Design Review, April 24, 2009 Outline Goals of G5 Test G5 layout and main components Parameters and regimes Plans & Conclusions

3. G5 Design Review, April 24, 2009 Why we are doing the G5 test? G5 test is first stage of ERL commissioning –Most of all ERL components can be tested during G5Test Will demonstrate of high brightness SRF Injector operating The high energy at the end We will measure: »Projected emittance in both planes »Bunch length and longitudinal tails »Slice emittance »Energy spread To have a base line for comparison of straight line and z- bend merger system performance

4. G5 Design Review, April 24, 2009 ERL setup

5. G5 Design Review, April 24, 2009 G5 setup

6. G5 Design Review, April 24, 2009 G5 test layout SRF 5cell cavity SRF Gun Triplet Beam Profile Monitors OTR/Yag Screens Dipole Solenoids Transport car Faraday Cup GUN S FCT Halo monitor S 5 cell RF - BPMs FC ERL quad triplet quad interchangeable screen/slit 0.3 m 14º - OTR/YaG screens Pepper-pot S - Steering dipoles 1.95 m

7. G5 Design Review, April 24, 2009 G5Test: Components SRF Gun and 5cell cavity, Cryosystem for both 1MW Klystron and 50kW RF power supplies, LLRF Vacuum chambers, pumps, control Cathode, Deposition System, Transport Car, Laser, Laser Control Magnets and Power Supplies: HTS solenoid, solenoids, steering dipoles, quadrupoles, 14° dipole (ERL 60° dipole will be used) Instrumentation: beam profile monitors, beam position monitors, beam current monitor

8. G5 Design Review, April 24, 2009 Main parameters for G5 test Charge per Bunch: 0.05-5 nC Gun Energy: 2.5 -3 MeV Maximum Energy: 20 MeV Max. Average current: 500 nA Max. Rep Rate: 100 Hz Average Power: < 10 Watts Trains mode operation

9. G5 Design Review, April 24, 2009 Electron beam parameters and regimes for G5test Start-upBase lineHigh charge CathodeCooperMulti-Alkaline Long. Pulse shape (FWHM) 12 psec Sin(x)/x50 psec flattop70 psec flat top Trans. Pulse shapeGaussian2.5 mm sharp edge3 mm sharp RF frequency703.55 MHz Operational regemPulses of trains Rep. rate in train9.383 MHz Train length100 pulses Trains rep. rate0-1 Hz Charge per bunchupto 50 pC1.4 nC5 nC Gun kinetic energy2.0 MeV 2.5 MeV Max. Energy20 MeV Max average current0.001 mA Max average power20 W

10. G5 Design Review, April 24, 2009 Beam Parameters to Measure At 20MeV two operational modes: 1.Straight ahead –projected emittance –transverse halo 2.With the bend –bunch length / long. halo /energy spread –slice emittance Plan to do at low energy - Cathode QE and - Cathode lifetime in SRF gun - Slice emittance - Projected emittance - Halo studies GUN S FCT Halo monitor S 5 cell RF - BPMs FC ERL quad triplet quad interchangeable screen/slit 0.3 m 14º - OTR/YaG screens Pepper-pot S - Steering dipoles 1.95 m

11. G5 Design Review, April 24, 2009 Straight ahead path: Quad scan Only one quad of the triplet is used for quad scan. Assuming that PS’s are unipolar, the first quad can be used for the horizontal quad scan, while the second quad can be sued for the vertical scan.  x,min 200  m y max (95%) 6 mm  x (Parmela) 1.43  m  x (“reconstructed”) 1.45  m 1 st quad  y,min 135  m x max (95%) 6 mm  y (Parmela) 1.43  m  y (“reconstructed”) 1.46  m 2 nd quad We will be able to measure emittances in 1  m range

12. G5 Design Review, April 24, 2009 G5 test Status During the 5cell cavity Cold Emission Test: –5cell cavity (Cryo, Vacuum, Controls, RF PS, LLRF) tested ( 20 MV/m achieved in pulsed mode). –PASS, MPS and general control systems tested –BLMs, pin diodes, PMT, chipmunks tested –Next CET Feed back system needs to be tested. SRF Gun is under-construction in AES. 1MW RF power supply has been tasted. Waveguide components to SRF Gun needs to be designed Laser is here and will be tested soon. Laser beam delivery system is under constraction. Cathode deposition system and transport car are in 966 Dipole and quads are tested and available All solenoids (HTS and normal) assembled, magnetic measurements needs to be done. Some ERL vacuum components will be reused other were designed Steering dipoles need to be design Main magnets power supply are here, lower current PS needs to be purchased Beam profile monitors (Radiobeam) will be reviewed next month Pepper pot system and Faraday cup (preliminary discussed with Princeton scientific) Halo monitor (there are two crosses -place holders for halo monitors) needs to be designed

13. G5 Design Review, April 24, 2009 Commisionnig plan: ERL fully operational in 2011 We start commissioning of the R&D ERL components 5cell SRF cavity cold emission test first cool-down March, 14, 2009 20 MV/m in CET April, 23 2009 G5 test (low average current) work in progress First, the straight pass (gun -- 5 cell cavity -- beam stop) test for the SRF Gun performance studies. (October 2010) #Metal cathode (low charge per bunch) #Multi-Alkaline Cathode (up to 5nC per bunch) Next, a novel concept of emittance preservation in a beam merger at the lower energy will be tested ( end of 2010) After recirculation loop completed, demonstrate energy recovery of high charge and high current beam.The prototype will serve as a test bed for studying issues relevant for very high current ERLs ( 2011 ) Proof of principle coherent electron cooling ions in RHIC at ~ 40 GeV/n is feasible with existing R&D ERL parameters ( ERL available around 2012 )

14. G5 Design Review, April 24, 2009 2-3 MeV 20 MeV 2-3 MeV SC RF Gun SC 5 Cell cavity Beam dump BPM DCCT 1MW Klystron SRF Linac 50 kW Transmitter operational Arc assembly QuadrupoleDipole Tested in BLD912 ready for gun First cool- down, March, 2009 T=2K Measured, ready to be installed BNL R&D ERL: Status

15. G5 Design Review, April 24, 2009 Thank you

16. G5 Design Review, April 24, 2009 Backup slides

17. G5 Design Review, April 24, 2009 Transport car Under two ion pumps operation, the baseline vacuum is 2*10-8torr without baking. Baking the transport car. The temperature is kept at 200C except the bellow which is kept at 150C for 50 hours. The baseline vacuum is 3*10 -8 torr after baking.( We don’t know why until now) Leak test. No leak on the transport car.

18. G5 Design Review, April 24, 2009 BNL R&D ERL Status: complete Design of major ERL components is completed. Hardware components are being manufactured and/or procured. –ERL Enclosure (Vault) was constructed (2005) –5-cell Cavity is being processed and tested at JLAB, installed at 912. First cool down T=2K in March 2009. Cold Emission Test next week. –The preparation chamber for SRF gun photo-cathodes under vacuum studies –1 MW Gun klystron (for SRF gun) including circulators and dummy loads installed, tested for full power 1MW –50 kW (for 5 cell 20 MeV SRF linac) installed, tested –Recirculation loop magnets and injection line magnets have arrived and measured. Magnets power supplies were delivered. –Loop vacuum system components are on hand –RF control will be based on the new digital RHIC LLRF. The LLRF system is currently under development. (CET will use PLL based LLRF and move to digital LLRF then one is available). –Machine protection system is installed

19. G5 Design Review, April 24, 2009 BNL R&D ERL Status: to do list.. Laser room completion (April, 2009) Gun drive laser is been procured (arriving in May, 2009) G5 test additional components designed some needs to be ordered yet (June 2009) Extraction line component, magnets, vacuum chamber under design Gun is under construction at AES (Cold Emission Test at BNL October 2010)

20. G5 Design Review, April 24, 2009 5-Cell cavity, full load Start: 650 L, 80 kg (density=123.9 g/L) End: 304 L, 44.3 kg (density=145.6 g/L) Unusable volume: 100 L Usable Volume: 204 L at 145.6 g/L = 29700 gr. Usable heat capacity: 29700 x 23.4 J/g =695 000 Joules Usable time: 695 700 J / 50 W / 3600 s/hr = 3.8 hours

21. G5 Design Review, April 24, 2009 Gun Start: 167 L, 20.7 kg (density=123.9 g/L) End: 78.1 L, 11.4 kg (density=145.6 g/L) Unusable volume: 20 L (17L) Usable Volume: 58.1 L at 145.6 g/L = 8460 gr. Usable heat capacity: 8400 x 23.4 J/g = 197 964 Joules Usable time: 197964 / 14 W 3600 s/hr = 3.9 hours