1. Peter McIntosh (STFC Daresbury Laboratory) 2 nd PASI Workshop, RAL April 3 - 5, 2013

2. Daresbury Test Facilities: –ALICE: SRF Cryomodule R&D RF Control – Microphonics and Lorenz Detuning –EMMA NS-FFAG: Beam Dynamics Studies RF Control – Vector Sum Architecture –VELA: Deflecting Cavity Diagnostics Collaborative Opportunities Conclusions Overview

3. ALICE at Daresbury Laboratory operates using Energy Recovery principle. Only accelerator of its type in Europe. Used as an R&D test facility for next generation electron beam technology development. Booster Compressor IR-FEL Photoinjector Laser Linac Acceleration Deceleration 8 MeV 35 MeV 8 MeV http://www.stfc.ac.uk/ASTeC/Programmes/Alice/35997.aspx ALICE ERL Facility

4. ALICE Operating Parameters ParameterDesign ValueOperating Value Gun Energy (keV)350320 Injector Energy (MeV)8.357 ERL Energy (MeV)2723 Total Beam Energy (MeV)3530 RF Frequency (GHz)1.3 Bunch Repetition Frequency (MHz)81.2581.25/16 Train Length (µs)0 - 100 Train Repetition Frequency (Hz)0 - 20 Compressed Bunch Length (ps)<1 rms<1 rms (measured) Bunch Charge (pC)8040/80 Energy Recovery Rate (%)>99>99 (measured)

5. New SRF Cryomodule Collaboration formulated in early 2006 to design and fabricate new CW cryomodule and validate with beam. Dimensioned to fit on the ALICE ERL facility at Daresbury: –Same cryomodule footprint. –Same cryo/RF interconnects. –‘Plug Compatible’ with existing cryomodule. ParameterTarget Frequency (GHz)1.3 Cryomodule Length (m)3.6 R/Q (  ) 762 E acc (MV/m)>20 E pk /E acc 2.23 H pk /E acc 46.9 CM Energy Gain (MeV)>32 QoQo >10 10 Q ext 4 x 10 6 - 10 8

6. CM Component Testing DESY superstructures (7Z2 & 7Z4) modified to incorporate optimised end groups. Saclay-II tuner with wider aperture and low voltage piezo cartridges, pinned and stress tested. Modified Cornell ERL injector coupler with a shortened cold section, high power conditioned. Cavities, cold couplers and central HOM absorbers installed. Cryomodule assembled & undergoing final cold testing.

7. Assembly and Integration

8. DLLRF Implementation LLRF4 –Designed at LBNL by L.Doolittle –Open source –Xilinx spartan 3 FPGA –4 -14 bit ADC Channels –2 -14 bit DAC's –USB comms –Clock management chip Cost ~$3k, built and tested System installed in 2011 on NC buncher cavity. To also install on SRF cavities: –1.3 GHz. –High Q Superconducting Cavities. –4ms pulse & CW –Fast feedback –Feed Forward for beam loading compensation.

9. ParameterValue Energy range10 – 20 MeV LatticeF/D Doublet Circumference16.57 m No of cells42 Normalised transverse acceptance3 mm Frequency (nominal)1.3 GHz No of RF cavities19 Average beam current13 μA Repetition rate1, 5, 20 Hz Bunch charge16-32 pC single bunch EMMA NS-FFAG http://www.stfc.ac.uk/ASTeC/Programmes/17426.aspx

10. Applications of NS-FFAGs High power proton driver Neutrino FactoryProton & Carbon Therapy Dedicated Muon Source Accelerator driven reactor

11. Fixed energy operation to map closed orbits and tunes vs momentum Many lattice configurations –Vary ratio of dipole to quadrupole fields –Vary frequency, amplitude and phase of RF cavities Map longitudinal and transverse acceptances with probe beam from ALICE EMMA is heavily instrumented with beam diagnostics EMMA Objectives

12. Ion Pump Cavity D Magnet F MagnetLocation for diagnostics Beam direction Girder EMMA 6-Cell Girder Assembly

13. YAG Screen eBPM x 81 Septum Power Supply Kicker Power Supplies Septum Power Supply Kicker Power Supplies EMMA Ring Configuration Wall Current Monitor LLRF

14. Realisation of EMMA August 2010 First TurnSecond Turn 16 th Aug 2010

15. Optimising RF for Acceleration ToF zero crossing of each cavity to find optimum phase angle. Beam loading effects could be seen on Libera system during phase optimisation. Possibility to zero cross each cavity, tune for maximum acceleration. Close Libera RF control loop to keep track of the correct phase of the system: –phase accumulator is reset during sweep. LLRF control essential in order to achieve successful beam acceleration.

16. EMMA Acceleration Achievement Successful acceleration in serpentine channel demonstrated. Published in Nature Physics (01/03/12) Measured March 2011

17. VELA – Versatile Electron Linear Accelerator (ex EBTF) For the development and testing of novel and compact accelerator technologies. Through partnership with industry and the scientific community. Aimed at addressing applications in medicine, health, security, energy, industrial processing and science. Will enable research into areas of accelerator technologies which have the potential to revolutionise the cost, compactness and efficiency of such systems. The main element of the infrastructure:- high performance and flexible electron beam injector facility feeding customised state-of- the-art testing enclosures and associated support infrastructure. Critical for development of underpinning technologies; –Advanced Beam Diagnostics, –Accelerating and Dipole Mode RF Structures, –RF Sources and Distribution Systems, –Vacuum Systems, –Magnet Systems, –Beam-based Feedback and Control Systems, –Beam Synchronisation Systems. VELA Pulsar

18. Module 1 Module 2 Module 3 Module 4 Module 5 Module 6 Module 1 Accelerator Modules http://www.stfc.ac.uk/ASTeC/Programmes/EBTF/38426.aspx

19. VELA/CLARA Beam Parameters VELA (Min)VELA (Max) CLARA (single spike) Min/Max CLARA (seeding) Min/Max Comments Beam Energy4 MeV6 MeV6 /25 MeV Magnets in VELA can go up to 25 MeV later for CLARA and some diag devices will be used at this higher energy. Bunch Charge10 pC250 pC10 pC250 pCExperimental modes Bunch length (σ t,rms )80 fs3 ps 35 fs /3ps (@25 MeV) 50 fs /3ps (@25 MeV) Bunch length changes along the line. CLARA in bunch compression mode. Experimental modes. Normalised emittance 0.1  m2.0  m 0.1/1 µm0.6/3.0 µm CLARA in bunch compression mode. Experimental modes Beam size (σ x,y,rms )0.1 mm3.5 mm0.1/2.0 mm0.1/4 mmVaries along the beam line Energy spread (σ e,rms )0.1%5%~ 0.1/1 %~ 0.1/5%Varies along the beam line Bunch repetition rate1 Hz400 HzTBD Klystron Modulator & Laser 400 Hz

20. Transverse Deflecting Cavity Beam Diagnostic Parameter Value Number of cells 9 Frequency (MHz) 2998.5 Nominal/Maximum RF voltage (MV)5 Nominal/Maximum RF power (MW)5/6 Operating Modeπ Repetition rate (Hz)10 Active length (m)0.5 Quality factor (Q o )~18000 Shunt Impedance deflecting mode R (MΩ)5.0 Aperture beam pipe diameter (mm)35 (Iris 32)

21. H-field E-field TDC Characterisation Estimated peak transverse voltage 5 MV (limited by available RF power) 3-cell TDC prototype (RI GmbH)

22. VELA Status and Layout Injector RoomEnclosure 2 Rack Room Synchronisation Room Laser Room Control Room

23. SRF Cryomodule Operation (ALICE): –CW SRF Cavity Operation: Thermal Characterisation –Microphonics Assessment & feedback/forward Control NS-FFAG Beam Dynamics (EMMA): –Serpentine Acceleration –RF Control Processes –Slow RF acceleration – Induction techniques? –Magnet Systems (Conventional & SC) Deflecting/Crab Cavities (VELA/ALICE/EMMA): –Structure Designs –RF Control Developments Vacuum Systems (VELA/ALICE/EMMA) Collaborative Opportunities

24. Innovative and unique accelerator test facilities available at Daresbury: ALICE – Europe’s only ERL Facility EMMA – World’s only NS-FFAG VELA – High performance beam injector Each allow for technology development and/or demonstration. Although machines use electrons, compliance exists for proton technologies: Accelerator Systems RF Control/feedback/feed-forward/synchronisation Deflecting/Crab Cavity Systems (Diagnostics/Beam Manipulation) Magnets Vacuum Systems Opportunity to explore UK-FNAL collaboration in these (or other) areas. Conclusions

25. THANK YOU!