Ideas for medium and long term facility upgrade Roberto Corsini for the CLIC Accelerator Collaboration

Short term upgrade Present Future: CALIFES minimum upgrade configuration RF deflector Test Area Spectrometer Add an available S-band klystron + modulator (N.B.: present one goes to AWAKE!) More RF power (beam energy), more operational flexibility (power in 1st structure, phase in structures 2 and 3), shorter bunches, possibility of running without RF pulse compression Option: use another S-band klystron + modulator to power existing RF deflector (bunch length measurements) Reconfigure present TBM area as test area Most (all) hardware already existing

Present CALIFES RF network Building 2010 CLEX 2009-2016

RF Upgrade KLYSTRONS AND MODULATORS 1st FLOOR G. McMonagle Building 2001 Building 2010 Implementation of Klystrons and Modulators in CTF3 Building 2013 MKS 30 Implementation of Klystrons and Modulators in CTF3 KLYSTRONS AND MODULATORS 1st FLOOR BUILDINGS 2001, 2013 and 2010

RF upgrade – present status MKS 30 Existing CALIFES set up 5 Hz repetition rate MKS30 will be transferred to AWAKE G. McMonagle

RF Upgrade – constraints & options Some modulators will not be supported by TE-EPC and BE-CO next year What can be reused for CALIFES to give more flexible performance and higher energy if necessary? 1st step: use compatible modulators in existing position, no upgrade for rep rate 2nd optional step: rep rate upgrade, optimize position Other considerations to be taken into account Main water cooling station must be kept operational Two water temperature stabilization stations to be kept operational Pulse compressor temperature control station to be operational Low Level RF and high power RF (klystrons) spares available from the other CTF3 modulators G. McMonagle

RF upgrade – proposal G. McMonagle

RF upgrade – proposal G. McMonagle

By using suggested modulators No support from TE-EPC needed for high power RF Removes incompatibility with future controls interface Using MKS31 all in place just waveguide configuration to change Most waveguides are available somewhere in the CTF3 facility Using MKS07 Modification of waveguide configuration Movement of charging supplies, PLC etc. from MKS 11, cabling costs manpower Keeps all CALIFES modulators in buildings 2010 and building 2013 Using MKS11 (instead of 07) Just waveguide modifications But modulator situated in building 2001 Using MKS30 area Transfer solid state modulator 21 from building 2001 to building 2010, allows 50Hz rep rate for structure testing. Waveguide modifications G. McMonagle

Other upgrades (or consolidation issues) Driven by: Experimental needs (assessment to be done after workshop – need information!) Practical considerations (reliability and availability, ease of maintenance, running cost…) Driven by experimental requirements I, beam parameter improvements: Shorter bunches Higher charge per bunch Higher total charge / longer trains Smaller emittance Higher rep rate Higher beam energy Driven by experimental requirements II, operational Pump and probe capability (independent tuning of time/position of two or more bunches) X-band RF power Available space for experiments Multiple beam lines Timing, synchronization, others

Beam parameters, wish list Bunch length 100 fs range most users Charge per bunch up to 5 nC THz, beam loading Train length 200 ns range beam loading Emittance < 1um plasma Energy up to 500 MeV Synchrotron rad down to 5-10 MeV VESPER Rep rate 25 Hz X-band Double bunch impedance, plasma Pulse shaping plasma, X-FEL … to be completed

CALIFES laser issues Issues: long (70 m) optical transfer line (pointing instability, power losses, aberrations) Photoinjector laser lab (1st floor) and optical transfer line to PHIN and CALIFES Front End Harmonic- generation Amplifier CALIFES PHIN Issues: quite complex no turn-key system, not optimized to CALIFES (new) needs. Maintenance/spares to be checked.

CALIFES laser Today’s CALIFES setup Pulse-picker with step size >1 bunch Today’s CALIFES setup

CALIFES laser, issues and upgrades Laser pulse shape Pointing instability Curtesy of W. Farabolini Curtesy of W. Farabolini Consider to: Move laser lab closer to CALIFES gun Simplify/consolidate present system Change laser to new one (commercial?) Others… Need input on parameters (pulse length, rep rate, stability, pulse shaping)

Laser upgrades Many applications need/would prefer improved laser parameters, e.g.: Shorter pulses (< 1 ps) Bunch comb (16 bunches…) Pulse shaping Higher power/pulse Consider also the possibility of double pulse with tunable distance Some proposed applications would need a different dedicated laser system Other don’t strictly need it, but may profit Need to understand parameters range, cost, infrastructure, manpower and maintenance needs, as well as potential synergies

X band capability - BOX1 connection Availability of X-band high power RF is an asset for CALIFES XBOX1 obvious choice Actually feed CTF2 test area and/or Dogleg beam loading experiment Low-loss RF line may be readapted and moved Alternative: move XBOX1 on top of desired location XBOX1 Low-loss RF transfer Drive beam, 1-3A, 100-50 MeV  50 mm circular waveguide CTF2 test area Dogleg experiment

Space availability The present CALIFES beam line is quite crowded. Even completely dismantling the Two-Beam Module, only a few meters will be available for equipment May sacrifice matching sections, instrumentation, spectrometers, but… Need to understand space requirements, typical times for installation and turnaround, compatibility, synergies Option: second beam line

Space availability

Options for a second beam line In CLEX there’s plenty of (transverse) space for a 2nd beam line (and possibly a 3rd one as well) Plenty of hardware to recuperate Dogleg can be used for compression Longitudinal space still limited May consider to extend towards CTF2

New source/gun Pump and probe experiments (Plasma, THz, impedance) would profit from a second independent electron source. A new source can also be optimized for short bunches and low emittance, beyond reach of the present CALIFES gun. A new source would not only be a tool, but an R&D goal in itself Some attractive possibilities: X-band photoinjector, plasma-based source Possible synergy with AWAKE (100 fs, ~ 400 A peak current, 50 MeV) See Steffen’s talk

Options for a second beam line + source 2nd line (alternative) New source Test area CALIFES 2nd line CLEX