phil Oxford , june 18 Photoinjector at

LAL activities

Brief LAL History A new accelerator at LAL (photoinjector - 9 MeV) 1955 : fisrt linac at ORSAY 1960 to 1980 : collaborations CERN, Italy, 1967 synchrotron radiation (ACO) 1977 DCI e+/e- collsions 1985 : LAL split in LAL & LURE 1988 : super ACO (synchrotron radiation) 2000 : LURE became synchrotron radiation SOLEIL 2001 : ELYSE (pulsed radiolysis facility) 2003 : linac of super ACO shut down (dismantlement) 2005 : PHIL (CARE Project) R&D and building activities Collaborations CERN (CTF), TTF, SLAC (FFTB) A new accelerator at LAL (photoinjector - 9 MeV)

PHIL brief history 2005 : LAL in CARE project : RF gun for CERN & LAL 2006 : LASER for PHIL (HQ Laser) 2007 : start of installation in old LINAC building (building modifications, bunker build up,…) 2008 : ASN deadline for PHIL PHIL start ok 2009 : fisrt beam ?

PHIL Goals Developpement of electrons sources & associated technologies Provide electron beam for different users Formation (students, thesis,…) Maintain & improve know-how@LAL for future accelarator projects New accelerator in LAL/Orsay

Possible applications TEST BENCH FOR: RF technology and high brillance guns design New Cathodes High gradient structures Low energy diagnostics Simulations code Laser pulse shaping … USERS Detector calibration (charge ,energy) Chemistry reactions Plasma acceleration with external injection

Photoinjector principle F = q Ef RF (EM wave) Acceleration of charged particle Laser beam Electron beam Ef Copper pillbox cavity Temporal structure are identical Standing wave with on axis Electric field short duration electron bunch (ps or below) Electron production with photoemission (cathode inside cavity) Ef ~ 80 MV/m leads to E ~ 4 MeV in 10 cm (3GHz)

Photoinjector parts Photon source : laser Nd:YLF Electron source : RF gun + photocathode RF source : electric field for acceleration Transport line : beam properties caracterization (size, duration, charge,…) 5. Status & Planning

PHIL installation 2.5 m photon source RF source User area electron source

PHIL laser Photon source Bought from HQ Laser in 2006 Oscillator Nd-YLF F= 74,963750MHz W/impulsion: 2 nJ X 2 1 mJ Amplification Nd-YLF gain ~ 106 80 µJ Pockels cell X 2 Bought from HQ Laser in 2006

Laser transport Photon source Upper view Accelerator room laser room 80 µJ/pulse 2 m laser = 266 nm F = 5 Hz 50 µJ/pulse Virtual cathode Streak camera RF gun cathode Length of transport ~ 17 m Laser position stabilisation

PHIL RF gun 20 mm Electron source HFSS simulations F = 3 GHz, 2.5 cell RF gun for CERN/CLIC 20 mm

Photocathode Electron source Q Cs2Te photocathode Start with copper ~ 100 pC CsTe cathode ~ 4 nC transfert arm Project with CERN - Other types of photocathodes ? Versatility of injector : - high level detection signal - low emittance - short pulses Q Te = 20 nm Cs = 16 nm Cs2Te photocathode CsTe QE ~ 8% fabrication QE ~ 1 % after few hours of RF (co-evaporation is better) Life time ~ several months Detail of Transfert arm

RF source RF source THALES Klystron (2040 type – 2001) Pmax = 20 MW COUPLER 6 dB CIRCULATOR Pik Prk SF6 Pic pump Prc pump Low level Input 140 W – 3 µs THALES Klystron (2040 type – 2001) Pmax = 20 MW (230 kV – 250 A) Gain ~ 52% RF GUN MODULATOR KLYSTRON RF duration = 3 µs

RF transport RF source COUPLER 6 dB CIRCULATOR Pik Prk SF6 Pic Prc pump Prc pump PA RF GUN BOOSTER MODULATOR KLYSTRON

Beam transport line

PHIL beam transport line RF input 1 m booster emittance screen pump RF gun BPM WCM Vacuum valve laser Beam catcher slit solenoids Cerenkov 60° dipole Fisrt version

Beam caracteristics Energy 5 MeV ±1 % Duration 5 < t < 10 ps Rep. rate 5 Hz Single laser pulse Charge 100 pC to ~ 2 nC Emittance 5 < e < 15 p mm.mrad Diameter 2 < d < 10 mm End line Fisrt version of accelerator

Project status V0 production Transport Diagnostic security RF power 15/06/09 production Transport Diagnostic security RF power magnets & Power supplies Faraday cage 1 Autorisation ASN Isolator Beam line WCM-BPM Autorisation UDIL Laser Vacuum Faraday cage 2 Radiation meas. First beam cathode Energy meas. RF gun klystron July 2008 BPM Leaks ! march 2009 Pelletier Reparation installation copper Tests ok. Not installed Regulation T°C E = 5 MeV Q = 100 pC F = 5 Hz

Global Planning Version Main characteristics Date Budget V0 (5 MeV, 100pC) Initial state : RF gun & first basic diagnostics (charge , energy) sept 2009 CARE+ IN2P3 V1 Full diagnostics (beam size, bunch length, emittance) dec 2009 P2i V2 Booster & CsTe cathode (9 MeV, 2 nC) mar 2010 IN2P3+ ANR +other First users (LAL) Sept 2010 ?

Thank you for your attention 18/06/09 H. Monard monard@in2p3.lal.fr