LCLS Gun Fabrication and Testing David H Dowell

LCLS Gun Fabrication and Testing David H. Dowell Facility Advisory Committee Meeting October 12, 2006 • Status of gun fabrication and testing • Gun test results • Characterization of magnetic components • Cathode qualification chamber operational • Gun high power testing in Klystron Lab • Summary LCLS FAC October 12, 2006 RF Gun Fabrication & Testing 1 David H. Dowell dowell@slac. stanford. edu

Gun Fabrication and Testing Process ü ü ü ü Fabricate parts Cold test sub assemblies and clamped parts Machine and measure for resonance and field balance Braze and weld final assembly Low power RF and cathode tests Furnace bake at 500 deg C Assemble and configure for high power RF test (hot test) Vacuum bake of assembly in Klystron test vault Perform hot test Vacuum qualification of gun Alignment of assembly with CMM Install at S 20 LCLS FAC October 12, 2006 RF Gun Fabrication & Testing 2 David H. Dowell dowell@slac. stanford. edu

RF Gun Fabrication and Cold RF Testing Finished & Preparing for High-Power Tests Gun only pictures CAD cut away view of gun interior LCLS FAC October 12, 2006 RF Gun Fabrication & Testing 3 David H. Dowell dowell@slac. stanford. edu

RF Field Balance Measured Using Bead Drop Technique Data compliments J. Wang, ATR Dept. , SLAC LCLS FAC October 12, 2006 RF Gun Fabrication & Testing 4 David H. Dowell dowell@slac. stanford. edu

Gun Design and Measured Specifications RF Parameters Design Measured fp (GHz) 2. 855987 2. 855999 Q 0 13960 14062 β 2. 1 2. 03 Mode Sep. f (MHz) 15 15. 17 Field Balance 1 1 LCLS FAC October 12, 2006 RF Gun Fabrication & Testing 5 David H. Dowell dowell@slac. stanford. edu

LCLS RF Gun: Cathode Side focusing solenoid dual rf power feed cathode flange LCLS FAC October 12, 2006 RF Gun Fabrication & Testing 6 David H. Dowell dowell@slac. stanford. edu

LCLS RF Gun: Beam Side dual rf power feeds focusing solenoid beam port: Attach 2 -km linac here LCLS FAC October 12, 2006 RF Gun Fabrication & Testing 7 David H. Dowell dowell@slac. stanford. edu

Description of gun magnet system Gun solenoid: SOL 1 Bucking coil: SOL 1 BK X, Y dipole correctors: XC 00&YC 00 (inside SOL 1) Normal & skewed quad correctors: CQ 01&SQ 01 (inside SOL 1) Field maps and calibrations measured LCLS FAC October 12, 2006 RF Gun Fabrication & Testing 8 David H. Dowell dowell@slac. stanford. edu

Gun Solenoid and Dipole Corrector Magnetic Measurements LCLS FAC October 12, 2006 RF Gun Fabrication & Testing 9 David H. Dowell dowell@slac. stanford. edu

Bucking Coil Magnetic Measurements LCLS FAC October 12, 2006 RF Gun Fabrication & Testing 10 David H. Dowell dowell@slac. stanford. edu

Cathode Qualification System (CQS) (1) (2) (3) (4) (5) (6) Vacuum chamber Cathode load port Viewport Cathode on rotation stage To RGA and gauge To vacuum pump LCLS FAC October 12, 2006 RF Gun Fabrication & Testing (7) XPS x-ray source (8) AES/SEM electron gun (9) XPS/AES energy analyzer (10) Cold cathode H+ gun (11) UV light and monochromator 11 David H. Dowell dowell@slac. stanford. edu

Cathode Qualification System • Measures either GTF- or LCLS-style cathodes • Ion-cleaning, XPS/AES, QE • Cathode carrier/storage containers are being fabricated LCLS FAC October 12, 2006 RF Gun Fabrication & Testing 12 David H. Dowell dowell@slac. stanford. edu

LCLS Cathode#1 Qualification (in CQS) H 2 -brazed, diamond fly cut, vacuum fired at 650 C for 24 hours LCLS FAC October 12, 2006 RF Gun Fabrication & Testing 13 David H. Dowell dowell@slac. stanford. edu

RF Gun/Solenoid Assembly in Klystron Test Vault LCLS FAC October 12, 2006 RF Gun Fabrication & Testing 14 David H. Dowell dowell@slac. stanford. edu

Summary of Gun Fabrication and Testing Gun fabrication and cold testing completed Gun meets all design goals All magnetic components calibrated and characterized Gun integrated with solenoid and waveguide assembly Installed in test vault at Klystron First bake of assembly (gun vacuum in high 10 -10 Torr) High-power RF (hot) testing has begun Final vacuum qualification & alignment performed after Hot. Testing Cathode processing chamber operational and producing cathodes for the gun Gun on schedule for Dec’ 06 installation LCLS FAC October 12, 2006 RF Gun Fabrication & Testing 15 David H. Dowell dowell@slac. stanford. edu