Post on 24-Feb-2016
description
Ion Source Development at RAL
Dan Faircloth
Including the work of:Scott Lawrie, Alan Letchford, Christoph Gabor, Phil Wise, Mark Whitehead, Trevor Wood, Mike Perkins, Mick Bates,
David Findlay, Juergen Pozimski, Simon Jolly, Pete Savage, David Lee
Dan Faircloth – Proton Meeting RAL Thursday 24th March
The ISIS Ion Source• Penning H- ion source• Surface plasma source (SPS)• Dudnikov type• 15 ml/min H2• 3 g/month Cs• 20 day average lifetime
Mounting Flange
Negative Ion Beam
Mica
Penning Pole Pieces
10mm
Slit Aperture
Plate
Water Cooling Channels
Source BodyAir Cooling Channels
Ceramic Spacer
Copper Spacer
Cathode
Hollow Anode
Discharge Region
Extraction Electrode
H2
Negative Ion Beam
Piezo Hydrogen Valve
Caesium Oven
Caesium Vapour Heated Transport
Line
Hollow Anode
50 A Discharge
+17 kV Extraction Voltage
10 mm
H2
Negative Ion Beam
Piezo Hydrogen Valve
Caesium Oven
Caesium Vapour Heated Transport
Line
Hollow Anode
50 A Discharge
+17 kV Extraction Voltage
Source Runs at 50 Hz Rep Rate
10 mm
Timing
Time
H2 Gas Pulse
~ 200 μs
Extraction Voltage Pulse~ 250 μs
Source Runs at 50 Hz Rep Rate
Discharge Pulse~ 600 μs
H- Beam
Cathode
Hydrogen Feed
Heated Caesium Transport Line
Air Cooling
Source Body
Hollow Anode
Discharge Power Feed
Thermocouples
Aperture Plate
Extraction Electrode
Support Insulators
Caesium Shields
Extraction Mount
3 Sources at ISIS
Operational Source
24 x 7 operation20 day average lifetime
200-300 μs pulse length50 Hz35 keV
35 mA @ RFQ
Ion Source Development Rig
Pre-test operationalsources
Problem solving
FETS Source
Experimental sources
High current
Long pulse
65 keV
FETS65 kV high
voltage platform
LaserDiagnostics
Vessel
3 Solenoid LEBT
Ion Source
+
Platform ground
-18 kV Pulsed
extraction power supply
Extraction electrode Aperture plate
Extraction gap
90 Sector magnet
Toriod 1
H- beam
FETS Source Schematic
Extraction electrode, coldbox and sector magnet all pulsed
Coldbox
65 kV Platform DC power supply
Post extraction acceleration gap
Laboratory ground
+-
160 MΩ 750 kΩ
Protection electrode
Ground planeSuppression electrode
P.S.
FETS source modifications
600520440360280200Steady state
calculation
Computational fluid dynamic cooling calculation
450
500
550
600
650
700
0 0.005 0.01 0.015 0.02 0.025 0.03
Time (seconds)
Tem
pera
ture
(C)
Cathode Surface
Anode Surface
ΔT= 73 ºC
ΔT= 39 ºC
Transient CalculationFinite Element Modelling
2.2 ms discharge at 50 Hz achieved with simple design changes
1. Extend discharge duty cycle
1. Extend discharge duty cycle
2. Discharge current
FETS source modifications
Experiments
For each extraction condition
there is a range of discharge currents that give minimum beam divergence
14 kV extraction voltage2.2 mm extraction gap
1. Extend discharge duty cycle 3. Permanent magnet Penning field
2. Discharge current
FETS source modifications
Nd2Fe14B Permanent Magnets
B
To allow different extraction voltages the Penning field must be decoupled from the sector magnet field
Permanent magnets are used to produce the produce the 0.15 – 0.25 T required for a stable discharge
1. Extend discharge duty cycle 3. Permanent magnet Penning field
2. Discharge current 4. Extraction
FETS source modifications
Voltage, Geometry and Meniscus
Increase voltage from 17 to 25 kV
2
23
B dVI
Child-Langmuir
-100
-80
-60
-40
-20
0
20
40
60
80
100
120
-100 0 100 200 300 400 500 600 700 800 900 1000
Ext V (kV)
Dis Cur (A)
H- (mA)
78 mA
Widen plasma electrode aperture
Meniscus Studies
Decrease extraction jaw separation
1. Extend discharge duty cycle 3. Permanent magnet Penning field
2. Discharge current 4. Extraction
5. Analysing magnet
FETS source modifications
Magnet RedesignDipole has a focusing component
Magnetic Field Gradient Index, n
dRdB
BR
ne
eField gradient index
0 0.5T
Field must be adequately terminated
Significant improvement in emittance
Size of good field region increased
Beam expands under space charge
Exact degree of compensation unknown
Optimum field gradient index n = 1.2 determined by experiment
1. Extend discharge duty cycle 3. Permanent magnet Penning field
2. Discharge current 4. Extraction
5. Analysing magnet
6. Post acceleration
FETS source modifications
Optimize Post Acceleration Gap
0 . 5 0
0 . 5 2
0 . 5 4
0 . 5 6
0 . 5 8
0 . 6 0
0 . 6 2
0 . 6 4
0 . 6 6
0 . 6 8
0 . 7 0
0 1 0 2 0 3 0 4 0
E l e c t r i c F i e l d [ k V / m m ]
no
rm.
rm
s-
em
itta
nc
e,
10
0%
x x ' e m i t t a n c e
y y ' e m i t t a n c e
Minimum emittance growth occurs for a post acceleration field of 9 kVmm-1
17 kV PA Voltage
Measured 355 mm from Ground Plane of PA Gap
11 kV PA Voltage 25 kV PA Voltage
Constant 10 kV Extraction Voltage 23 mA H - Beam Current
19 kV PA Voltage
55.0
mm
PA
Gap
9.2
mm
PA
Gap
2.5
mm
PA
Gap
2.0
mm
PA
Gap
12.5 kVmm-
19.5 kVmm-18.5 kVmm-15.5 kVmm-1
10 kVmm-
17.6 kVmm-1
6.8 kVmm-1
4.4 kVmm-1
2.7 kVmm-1
2.1 kVmm-1
1.8 kVmm-1
1.2 kVmm-1
0.5 kVmm-1
0.4 kVmm-1
0.3 kVmm-1
0.2 kVmm-1
Incr
easi
ng P
ost A
ccel
erat
ion
Gap
Len
gth
Increasing Post Acceleration Voltage
Isolating Column
1×10-4 mBar
6×10-5 mBar
Beam shutter
Slit-slit scanners
5×10-6 mBar
Retractable Faraday Cup
2000 Ls-1 Turbo Pump
Pepper pot or profile scintillator head
Camera
7×10-6 mBar
Solenoid 3
Toroid3
Solenoid 2
Solenoid 1
Toroid 1
Toroid 2
4 × 800 Ls-1 & 1 x 400 Ls-1 Turbo Pumps
Differential pumping and laser profile
vessel
400 Ls-1 turbo pump
Diagnostics vessel
Toroid 4
Laser Diagnostics
Short Pulse Operation <1ms
For pulse lengths shorter than 1 ms:80 mA at the ground plane60 mA at the entrance of the RFQ0.3 πmm.mrads r.m.s normalised
Results that follow are for 2 ms pulse lengths…
Vary Discharge Current- 20 to 50 ADischarge Current Discharge Voltage
Discharge Power Discharge Impedance
H- Beam Current
1. Increased Plasma Density• Increased H+ and Cs+ bombardment
sputters Cs from cathode surface.
• More H- are stripped on their way to the extraction region.
Possible Explanation of Droop:
2. Electrode Surface Temperature Rise
Transient 3D FEA calculations of electrode surface temperature
Higher discharge currents↓
Greater surface temperature rise during the pulse↓
Surface Cs coverage pushed away from optimum
Discharge Power
Vary Discharge Rep Rate
Vary Discharge Rep Rate
Vary Discharge Rep Rate
Lower repetition rate↓
More time between pulses↓
Longer time for Cs coverage to build up
Time Variation of Emittance:25 Hz 50 A discharge
500
Current (μA)
Current (μA)
450
400
350
300
250
200
150
100
50
0
300
270
240
210
180
150
120
90
60
30
0
0 µs
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Horizontal Vertical
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Beam Current
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
500
Current (μA)
Current (μA)
450
400
350
300
250
200
150
100
50
0
300
270
240
210
180
150
120
90
60
30
0
53 µs
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Horizontal Vertical
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Beam Current
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
500
Current (μA)
Current (μA)
450
400
350
300
250
200
150
100
50
0
300
270
240
210
180
150
120
90
60
30
0
105 µs
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Horizontal Vertical
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Beam Current
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
500
Current (μA)
Current (μA)
450
400
350
300
250
200
150
100
50
0
300
270
240
210
180
150
120
90
60
30
0
158 µs
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Horizontal Vertical
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Beam Current
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
500
Current (μA)
Current (μA)
450
400
350
300
250
200
150
100
50
0
300
270
240
210
180
150
120
90
60
30
0
210 µs
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Horizontal Vertical
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Beam Current
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
500
Current (μA)
Current (μA)
450
400
350
300
250
200
150
100
50
0
300
270
240
210
180
150
120
90
60
30
0
263 µs
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Horizontal Vertical
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Beam Current
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
500
Current (μA)
Current (μA)
450
400
350
300
250
200
150
100
50
0
300
270
240
210
180
150
120
90
60
30
0
315 µs
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Horizontal Vertical
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Beam Current
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
500
Current (μA)
Current (μA)
450
400
350
300
250
200
150
100
50
0
300
270
240
210
180
150
120
90
60
30
0
368 µs
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Horizontal Vertical
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Beam Current
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
500
Current (μA)
Current (μA)
450
400
350
300
250
200
150
100
50
0
300
270
240
210
180
150
120
90
60
30
0
420 µs
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Horizontal Vertical
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Beam Current
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
500
Current (μA)
Current (μA)
450
400
350
300
250
200
150
100
50
0
300
270
240
210
180
150
120
90
60
30
0
473 µs
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Horizontal Vertical
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Beam Current
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
500
Current (μA)
Current (μA)
450
400
350
300
250
200
150
100
50
0
300
270
240
210
180
150
120
90
60
30
0
525 µs
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Horizontal Vertical
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Beam Current
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
500
Current (μA)
Current (μA)
450
400
350
300
250
200
150
100
50
0
300
270
240
210
180
150
120
90
60
30
0
578 µs
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Horizontal Vertical
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Beam Current
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
500
Current (μA)
Current (μA)
450
400
350
300
250
200
150
100
50
0
300
270
240
210
180
150
120
90
60
30
0
630 µs
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Horizontal Vertical
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Beam Current
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
500
Current (μA)
Current (μA)
450
400
350
300
250
200
150
100
50
0
300
270
240
210
180
150
120
90
60
30
0
683 µs
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Horizontal Vertical
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Beam Current
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
500
Current (μA)
Current (μA)
450
400
350
300
250
200
150
100
50
0
300
270
240
210
180
150
120
90
60
30
0
735 µs
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Horizontal Vertical
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Beam Current
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
500
Current (μA)
Current (μA)
450
400
350
300
250
200
150
100
50
0
300
270
240
210
180
150
120
90
60
30
0
788 µs
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Horizontal Vertical
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Beam Current
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
500
Current (μA)
Current (μA)
450
400
350
300
250
200
150
100
50
0
300
270
240
210
180
150
120
90
60
30
0
840 µs
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Horizontal Vertical
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Beam Current
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
500
Current (μA)
Current (μA)
450
400
350
300
250
200
150
100
50
0
300
270
240
210
180
150
120
90
60
30
0
893 µs
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Horizontal Vertical
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Beam Current
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
500
Current (μA)
Current (μA)
450
400
350
300
250
200
150
100
50
0
300
270
240
210
180
150
120
90
60
30
0
945 µs
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Horizontal Vertical
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Beam Current
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
500
Current (μA)
Current (μA)
450
400
350
300
250
200
150
100
50
0
300
270
240
210
180
150
120
90
60
30
0
998 µs
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Horizontal Vertical
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Beam Current
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
500
Current (μA)
Current (μA)
450
400
350
300
250
200
150
100
50
0
300
270
240
210
180
150
120
90
60
30
0
1050 µs
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Horizontal Vertical
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Beam Current
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
500
Current (μA)
Current (μA)
450
400
350
300
250
200
150
100
50
0
300
270
240
210
180
150
120
90
60
30
0
1103 µs
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Horizontal Vertical
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Beam Current
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
500
Current (μA)
Current (μA)
450
400
350
300
250
200
150
100
50
0
300
270
240
210
180
150
120
90
60
30
0
1155 µs
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Horizontal Vertical
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Beam Current
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
500
Current (μA)
Current (μA)
450
400
350
300
250
200
150
100
50
0
300
270
240
210
180
150
120
90
60
30
0
1208 µs
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Horizontal Vertical
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Beam Current
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
500
Current (μA)
Current (μA)
450
400
350
300
250
200
150
100
50
0
300
270
240
210
180
150
120
90
60
30
0
1260 µs
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Horizontal Vertical
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Beam Current
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
500
Current (μA)
Current (μA)
450
400
350
300
250
200
150
100
50
0
300
270
240
210
180
150
120
90
60
30
0
1313 µs
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Horizontal Vertical
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Beam Current
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
500
Current (μA)
Current (μA)
450
400
350
300
250
200
150
100
50
0
300
270
240
210
180
150
120
90
60
30
0
1365 µs
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Horizontal Vertical
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Beam Current
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
500
Current (μA)
Current (μA)
450
400
350
300
250
200
150
100
50
0
300
270
240
210
180
150
120
90
60
30
0
1418 µs
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Horizontal Vertical
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Beam Current
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
500
Current (μA)
Current (μA)
450
400
350
300
250
200
150
100
50
0
300
270
240
210
180
150
120
90
60
30
0
1470 µs
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Horizontal Vertical
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Beam Current
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
500
Current (μA)
Current (μA)
450
400
350
300
250
200
150
100
50
0
300
270
240
210
180
150
120
90
60
30
0
1523 µs
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Horizontal Vertical
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Beam Current
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
500
Current (μA)
Current (μA)
450
400
350
300
250
200
150
100
50
0
300
270
240
210
180
150
120
90
60
30
0
1575 µs
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Horizontal Vertical
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Beam Current
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
500
Current (μA)
Current (μA)
450
400
350
300
250
200
150
100
50
0
300
270
240
210
180
150
120
90
60
30
0
1628 µs
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Horizontal Vertical
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Beam Current
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
500
Current (μA)
Current (μA)
450
400
350
300
250
200
150
100
50
0
300
270
240
210
180
150
120
90
60
30
0
1680 µs
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Horizontal Vertical
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Beam Current
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
500
Current (μA)
Current (μA)
450
400
350
300
250
200
150
100
50
0
300
270
240
210
180
150
120
90
60
30
0
1733 µs
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Horizontal Vertical
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Beam Current
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
500
Current (μA)
Current (μA)
450
400
350
300
250
200
150
100
50
0
300
270
240
210
180
150
120
90
60
30
0
1785 µs
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Horizontal Vertical
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Beam Current
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
500
Current (μA)
Current (μA)
450
400
350
300
250
200
150
100
50
0
300
270
240
210
180
150
120
90
60
30
0
1838 µs
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Horizontal Vertical
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Beam Current
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
500
Current (μA)
Current (μA)
450
400
350
300
250
200
150
100
50
0
300
270
240
210
180
150
120
90
60
30
0
1890 µs
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Horizontal Vertical
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Beam Current
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
500
Current (μA)
Current (μA)
450
400
350
300
250
200
150
100
50
0
300
270
240
210
180
150
120
90
60
30
0
1943 µs
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Horizontal Vertical
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Beam Current
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
500
Current (μA)
Current (μA)
450
400
350
300
250
200
150
100
50
0
300
270
240
210
180
150
120
90
60
30
0
1995 µs
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Horizontal Vertical
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Beam Current
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
500
Current (μA)
Current (μA)
450
400
350
300
250
200
150
100
50
0
300
270
240
210
180
150
120
90
60
30
0
2048 µs
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Horizontal Vertical
0.000.050.100.150.200.250.300.350.400.450.50
0 500 1000 1500 2000Time (µs)
Beam Current
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
Nor
mal
ised
RM
S Em
ittan
ce (π
mm
mra
d)
Time variation of Emittance Parameters for different conditions:
Phase space rotation caused by decompensation of the beam
HO
RIZ
ON
TAL
VE
RTI
CA
L
Normalised RMS Emittance Twiss Alpha Twiss Beta
IB8π2εHεV
Beam Brightness =
ISIS Source around the World
Chinese Spallation Neutron Source ESS Bilbao
CERN SLHC-pp Source DESY Linac4 LP-SPL HP-SPL
H- current (mA) 40 80 80 80RF peak power (kW) 30 100 100 100RF frequency (MHz) 2 2 2 2Repetition rate (Hz) 3 2 2 50Pulse length (ms) 0.15 0.4 1.2 0.4 - 1.2duty factor (%) 0.045 0.08 0.24 2 – 6Average RF power (W) 13.5 80 240 2000 - 6000
THE CHALLENGE:Over 3 times increase in powerOver 100 times increase in d.f.
Modelling and Prototyping
1.2 ms pulse length at 50 Hz 50 kW plasma stable
The Future• Up-rated power supplies• Better understanding of the plasma
- PhD research project with JAI
- Optical spectroscopy- Plasma modelling
• Scaled source• Understand lifetime limitations
Thank you for your attention
Questions, Comments?