Drive Beam Injector Gun
Kévin Pepitone
CLIC project meeting, CERN, December 1st, 2015
Kevin PEPITONE, BE-RF
1
LEETCHI
Low Energy Electron source
from Thermionic Cathode
at High Intensity
Drive Beam Injector Gun
Kévin Pepitone
CLIC project meeting, CERN, December 1st, 2015
Kevin PEPITONE, BE-RF
2
Status of LEETCHI for CLIC
Kévin Pepitone
CLIC project meeting, CERN, December 1st, 2015
Kevin PEPITONE, BE-RF
3
Outline
• Introduction and electron beam parameters
• Integration: experimental area, HV deck and control room
• Components: HV components and PLC system
• Diagnostics: electrical and optical diagnostics
• Simulations
• Perspectives
• Conclusions
CLIC project meeting, CERN, December 1st, 2015
Kevin PEPITONE, BE-RF
4
Introduction
LEETCHI
Conceptual design report
(EDMS 1234244)
CLIC project meeting, CERN, December 1st, 2015
Kevin PEPITONE, BE-RF
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Electron beam parameters
Parameters
Beam energy
Baseline
140 keV
From a thermionic cathode
Beam current
5 to 7 A
Pulse length
140 µs
Emittance (RMS)
Repetition rate
Beam power
Shot to shot charge variation
Flat top charge variation
CLIC project meeting, CERN, December 1st, 2015
< 20 mm mrad
50 Hz
4,9 to 6,9 kW
0.1 %
0.1 % after correction
Kevin PEPITONE, BE-RF
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2750
Integration
162/R-002
High voltage
6330
CLIC project meeting, CERN, December 1st, 2015
CLINFTLA0100
Kevin PEPITONE, BE-RF
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Integration – Experimental area
HV deck
Relay
Ross DC
High
voltage
Insulating
Capacitor
connected
to
150
transformer
power
10
nFkV/ supply
150 to
kV
the kV/10
-140
produce
-200
220kV
mA
Vac
CLIC project meeting, CERN, December 1st, 2015
Kevin PEPITONE, BE-RF
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Integration – HV deck
PLC
Bias power supply
300 V / 450 mA
Heater power supply
15 V / 10 A
Pulser power supply
-1000 V at repetition
rates up to 1 kHz
CLIC project meeting, CERN, December 1st, 2015
Kevin PEPITONE, BE-RF
9
Cathode and connector
PLC in the control room
Cathode
HV deck
Control interface
PLC
Optical fibre
Bias PS
+300 V, 0.45 A
Grid
+
Anode
+
Heater PS
15 V, 10 A
Electron beam
HV pulser
-1000 V
Cathode
CPI YU156
+
220 V
220 V
Insulating
transformer
- 140 kV
+
Ground
CLIC project meeting, CERN, December 1st, 2015
Kevin PEPITONE, BE-RF
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Cathode and connector
Bias +
Heater +
Heater -
Bias -
Pulser Pulser +
220 V
Insulating
transformer
+
Vadim Soldatov
CLIC project meeting, CERN, December 1st, 2015
Kevin PEPITONE, BE-RF
11
Integration – Control room
PLC
Media converter
Vacuum gauges
PLC touch screen
HVPS remote
Delay generator
Ion pumps PS
Solenoids PS
Contactors
Danish Ali Nawaz
CLIC project meeting, CERN, December 1st, 2015
Kevin PEPITONE, BE-RF
12
Dump and Diagnostics
3D thermal analysis (ANSYS)
3D drawing (CATIA)
Water
Bergoz
ACCT-S-C8
Northstar VD-150
230 kV, 20 MHz
OTR with silicon carbide target
50 mm diameter
Alex Vamvakas
Graphite dump (diameter at
the beginning : 40 mm, total
length : 390 mm)
Copper holder with
water-cooling
channels
Energy deposition calculated with Geant4
for 140 keV, 5A, 140 µs electron beam
Energy deposition
1000
Integrated energy deposition as
0.8
a function of length
0.6
600
Edep (J)
Edep (J/g)
800
400
0.4
0.2
Cedric200Delory
0
0.0
0
20
40
60
80
100 120 140 160
0
50
100 150 200 250 300 350 400
r (µm)
CLIC project meeting, CERN, December 1st, 2015
z (mm)
Kevin PEPITONE, BE-RF
13
Simulations
MAGIC simulation example of the electron gun
Electrical field simulations in the
cathode region to check possible
breakdown locations (Flux2D).
Maximum surface field 14 kV/cm
Current dependence of the
emittance for the 8 mm
cathode (EGUN)
Bucking
coil
Focusing coil
Cathode r = 8 mm
r-z at 10 ns
CLIC project meeting, CERN, December 1st, 2015
Jacques Gardelle, CEA
Bruno Cassany, CEA
Romain Pecquois, CEA
Steffen Doebert
Kevin PEPITONE, BE-RF
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Perspectives
Modular 7.5 kV board
Parameters
Baseline
Schematic of the modulator 40
during
kV prototype of the modulator
Beam energy
140 keV
Charging and Discharging
During HV tests
Vs
Vs
Beam current
Sn
Dbp
Srn
Sn
Dch
ETAGE N
Pulse length
C
Dch
Sn
Dbp
Srn
Dch
Emittance (RMS)
Repetition rate
Dbp
Sr2
Dch
ETAGE 2
S1
Dbp
C
Sr2
Dch
ETAGE 2
-10k
Dch
ETAGE 1
Dbp
Sr2
-20k
ETAGE 2
-30k
C
4,9 to 6,9 kW
Dch
Shot to shot charge variation
Sr1
0
140 µs
S1
Dbp
ETAGE N
S2
C
Dch
Beam power
Dch
Srn
50 Hz
S2
C
Dch
Dbp
< 20 mm mrad
S2
Dch
Dch
ETAGE N
C
Dch
Voltage waveform on
4.5 kΩ resistive load
5 to 7 A
Tension (V)
Dch
Vs
Dbp
-40k
S1
Sr1
0.1 %
Dch
ETAGE 1
Dbp
Sr1
ETAGE 1
-150µ -100µ -50µ
Dch
Ve
C
Dch
Flat top charge variation
CLIC project meeting, CERN, December 1st, 2015
Ve
C
Dch
C
0
50µ
100µ 150µ 200µ 250µ
300µ 350µ
Temps (s)
0.1 % after correction
Ve
Kevin PEPITONE, BE-RF
Bruno Cassany, CEA
Baptiste Cadilhon, CEA
Romain Pecquois, CEA
15
Conclusions
• 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
CLIC project meeting, CERN, December 1st, 2015
Kevin PEPITONE, BE-RF
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Thank you for your attention
CLIC project meeting, CERN, December 1st, 2015
Kevin PEPITONE, BE-RF
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