1. Kévin Pepitone 1CLIC workshop, CERN, 18-22 January 2016 Kevin PEPITONE, BE-RF LEETCHI: Drive Beam Electron Source

2. 2 Outline Introduction and electron beam parameters Integration: experimental area, HV deck and cathode connector Diagnostics: electrical and optical diagnostics Simulations Perspectives: modulator Conclusions Drive beam electron source automation control (Danish Ali Nawaz) CLIC workshop, CERN, 18-22 January 2016 Kevin PEPITONE, BE-RF

3. 3 Introduction LEETCHI CLIC workshop, CERN, 18-22 January 2016 Kevin PEPITONE, BE-RF 162/R-008

4. ParametersBaseline Beam energy140 keV Beam current5 to 7 A Pulse length140 µs Emittance (RMS)< 20 mm mrad Repetition rate50 Hz Beam power4,9 to 6,9 kW Shot to shot charge variation0.1 % Flat top charge variation0.1 % after correction 4 Electron beam parameters CLIC workshop, CERN, 18-22 January 2016 Kevin PEPITONE, BE-RF ParametersBaseline Beam energy140 keV Beam current5 to 7 A Pulse length140 µs Emittance (RMS)< 20 mm mrad Repetition rate50 Hz Beam power4,9 to 6,9 kW Shot to shot charge variation0.1 % Flat top charge variation0.1 % after correction From a thermionic cathode

5. Relay Ross 150 kV Insulating transformer to produce 220 Vac 5 Integration – Experimental area CLIC workshop, CERN, 18-22 January 2016 Kevin PEPITONE, BE-RF HV deck connected to the -140 kV High voltage DC power supply -200 kV/10 mA Capacitor 10 nF / 150 kV

6. 6 Integration – HV deck CLIC workshop, CERN, 18-22 January 2016 Kevin PEPITONE, BE-RF Pulser power supply -1000 V at repetition rates up to 1 kHz Bias power supply 300 V / 450 mA Heater power supply 15 V / 10 A PLC

7. 7 Cathode and connector CLIC workshop, CERN, 18-22 January 2016 Kevin PEPITONE, BE-RF Ground + - 140 kV Anode Cathode Electron beam Grid HV pulser -1000 V Heater PS 15 V, 10 A Bias PS +300 V, 0.45 A 220 V Insulating transformer 220 V + + + Control interface PLC Optical fibre PLC in the control room HV deck Cathode CPI YU156

8. 8 Cathode and connector CLIC workshop, CERN, 18-22 January 2016 Kevin PEPITONE, BE-RF + 220 V Insulating transformer -140 kV Heater + Pulser + Pulser - Heater - Bias - Bias + Vadim Soldatov

9. 9 Dump and Diagnostics CLIC workshop, CERN, 18-22 January 2016 Kevin PEPITONE, BE-RF Energy deposition calculated with Geant4 for 140 keV, 5A, 140 µs electron beam 3D thermal analysis (ANSYS) Energy deposition Integrated energy deposition as a function of length Cedric Delory Northstar VD-150 230 kV, 20 MHz Bergoz ACCT-S-C8 OTR with silicon carbide target 50 mm diameter e- beam

10. 10 Simulations CLIC workshop, CERN, 18-22 January 2016 Kevin PEPITONE, BE-RF Current dependence of the emittance for the 8 mm cathode (EGUN) MAGIC simulation example of the electron gun Focusing coilBucking coil Cathode r = 8 mm r-z at 10 ns Electrical field simulations in the cathode region to check possible breakdown locations (Flux2D). Maximum surface field 14 kV/cm Jacques Gardelle, CEA Bruno Cassany, CEA Romain Pecquois, CEA Steffen Doebert

11. 11 Simulations CLIC workshop, CERN, 18-22 January 2016 Kevin PEPITONE, BE-RF CST studio Tracking solver Potential E-field

12. 12 Perspectives CLIC workshop, CERN, 18-22 January 2016 Kevin PEPITONE, BE-RF ParametersBaseline Beam energy140 keV Beam current5 to 7 A Pulse length140 µs Emittance (RMS)< 20 mm mrad Repetition rate50 Hz Beam power4,9 to 6,9 kW Shot to shot charge variation0.1 % Flat top charge variation0.1 % after correction

13. 13 Perspectives Pspice simulation @ 50 HzPspice simulation @ 2.5 Hz CLIC workshop, CERN, 18-22 January 2016 Kevin PEPITONE, BE-RF Pspice simulation @ 50 Hz 10 mA power supply 1 1 1: Charge during 500 ms 2 2 2: First beam 3 3: Charge during 20 ms 4 4 4: Second beam After 7 beams @ 50 Hz, V beam < 40 kV

14. 14 Perspectives CLIC workshop, CERN, 18-22 January 2016 Kevin PEPITONE, BE-RF 40 kV prototype of the modulator During HV tests Modular 7.5 kV board Voltage waveform on 4.5 kΩ resistive load Schematic of the modulator during Charging and Discharging Bruno Cassany, CEA Baptiste Cadilhon, CEA Romain Pecquois, CEA

15. 15 Conclusions CLIC workshop, CERN, 18-22 January 2016 Kevin PEPITONE, BE-RF Integration and installation of the gun in the area are completed Vacuum is good New components are expected:  Optical diagnostic  Dump  Connector The first tests with short pulses beams will be performed in 2016 The tests with long pulses at 50 Hz should be performed in 2016

16. Thank you for your attention 16CLIC workshop, CERN, 18-22 January 2016 Kevin PEPITONE, BE-RF