AWAKE workshop, CERN, April 9 th -11 th , 2014 Steffen Döbert, BE-RF AWAKE electron source New Electron Source WP at CERN Base Line Scenario Simulations Diagnostics Questions and Issues Conclusions
Dec 27, 2015
AWAKE workshop, CERN, April 9th-11th, 2014 Steffen Döbert, BE-RF
AWAKE electron source
New Electron Source WP at CERN
Base Line Scenario
Simulations
Diagnostics
Questions and Issues
Conclusions
Base line scenarioBase line
• Use PHIN gun and equipment (convert to copper cathode ?)• Klystron and Modulator from CTF3• Get booster from Cockcroft/Lancaster collaboration (specs from
CERN) ?• Additional equipment needed (solenoids, vacuum, wave guides,
girders)• Diagnostics, PHIN, CERN, INFN (to be defined)• Beam dynamics simulations, CERN ,Cockcroft ?• Integrated test in CTF2 in 2016, external help welcome• Installation and commissioning into CNGS area in 2017, external help
welcomeAlternative, upgrade
• Look for alternative gun, Califes, Cockcroft/Lancaster, INFN ? (goal will be ultimate beam performance, tiny emittance, ultra short bunches)• Evaluate performance, impact and cost
Work package responsibilities
Tasks Responsible
RF power CERN, Gerry McMonagle
GUN CERN, Steffen, Eric Chevallay
Booster STFC, Graham Burt ?
Laser CERN, Valentin Fedosseev
Instrumentation CERN, Lars Jensen
Mechanical design CERN, Nicolas Chritin
Magnets CERN, Jeremie Bauche
Vacuum CERN, Jan Hansen
Controls CERN, Marine Gourber-Pace
Integration CERN, Fred, Ans Pardons
Commissioning CERN, Steffen, Chiara
Simulations CERN,STFC, Steffen, Oznur Mete ?
Interlocks, Safety CERN, Rui Nunes
Be aware this list is certainly incomplete and preliminary
Ion Pump ?
AWAKE – INJECTOR MODULE
RF Gun
Beam
Direction
Ion PumpSupport Pedestal
Synthetic Granite Girder
Booster Linac 1m long
YAG
Quadrupole Magnet
Slit
Horizontal and Vertical Corrector Magnet YAG
Proposal by STFC Daresbury
AWAKE electron sourceschematic
Length ~ 4 m
FC
E, DE
MS
BPR
Laser +Diagnostics
RF GUN
Emittance
Incident, Reflected Power and phase
Spectrometer
Corrector
MTV
VPI
FCT
AcceleratorMTV,
Emittance
Matching triplet
BPR
BPR
Incident, Reflected, transmitted Power
Klystron
A,f
Awake electron beamrequirements
Parameter Phase 1 Phase 2
Beam Energy 13-16 MeV 20 MeV
Energy spread (rms) 0.1 %
Bunch Length ~ 4 ps < 1 ps
Laser/Rf synchronization 1 ps 0.1 ps
Free Repetition Rate 10 Hz
Synchronized repetition rate 0.03 Hz
Beam Focus Size < 250 mm
Divergence < 3 mrad
Normalized Emittance 2-5 mm mmrad 0.5 mm mrad
Bunch Charge 0.2 nC 1 nC
Awake simulationsPhin gun, 20 MV/m structure, 0.1 nC, 1 mm 3 ps laser
-50 0 50 100 150 200 2500
0.1
0.2
z
Bea
m S
ize
x (c
m)
-50 0 50 100 150 200 2500
0.1
0.2
z
Bea
m S
ize
y (c
m)
0 50 100 150 2000
1
2
3
z
Em
i x
0 50 100 150 2000
1
2
3
z
Em
i y
0 50 100 150 2000
10
20
z
En
erg
y (M
eV)
0 50 100 150 2000
1
2
3
z
bu
nch
len
gth
(p
s)
Awake simulations
Phin gun, 20 MV/m structure, 0.2 nC, 1 mm laser
0 50 100 150 2000
1
2
3
z
Em
i x
0 50 100 150 2000
1
2
3
z
Em
i y
Awake simulationsPhin gun, 20 MV/m structure, 0.2 nC, 1 mm laser,
1 ps laser
-50 0 50 100 150 200 2500
0.1
0.2
z
Be
am S
ize
x (
cm
)
-50 0 50 100 150 200 2500
0.1
0.2
z
Be
am S
ize
y (
cm
)
0 50 100 150 2000
1
2
3
z
Em
i x
0 50 100 150 2000
1
2
3
z
Em
i y0 50 100 150 200
0
10
20
z
En
erg
y (M
eV)
0 50 100 150 2000
1
2
3
z
bu
nch
len
gth
(p
s)
Awake simulations
Phin gun, 20 MV/m structure, 0.1 nC, 0.5 mm laser
0 50 100 150 2000
0.5
1
z
Em
i x
0 50 100 150 2000
0.5
1
z
Em
i y
Awake simulations
Phin gun, 20 MV/m structure, 0.1 nC, 0.25 mm laser
0 50 100 150 2000
0.5
1
z
Em
i x
0 50 100 150 2000
0.5
1
z
Em
i y
Many variants are possibleClear laser and beam parameter specification are needed for the
simulationsShould define reference scenarios for the simulations
Booster structure
Some rough numbers1 m long constant gradient structuref= 2998.55 MHzQ ~ 15000r/Q ~ 70 MWDV= 15 MVTf= 280 ns, 2a ~ 2 cmPo = 11 MW
PHIN gun needs about 10 MW for 85 MV/m
Roughly 30 MW needed to power the injector (one klystron)
Laser diagnostics: laser power, position, virtual cathode, micro pulse length
RF diagnostics: rf power signals, rf phase
Beam instrumentation
Instrument How many Resolution Precision
BPMs 3 50 mm ? ?
Phase monitor 1 ps ? ?
Screen 3 20 mm ? ?
Multi slit 1 < mm mrad ? ?
FCT 1 pC ? ?
Faraday Cup 1 pC ? ?
Spectrometer 1 10 keV ? ?
Streak Camera 1 < ps ? ?
Define rough commissioning scenario, what do we measure where and how
Klystron Issues Transport: Study of transport and possibility to
exchange klystron in situ has to be done, likely a
local lifting device is needed
Synchronisation: 3 GHz synchronized signal is
needed as well as a number of timing triggers
Safety: The modulator contains Oil together with
high voltage, the waveguide may contain SF6
A risk assessment has to be done to determine fire
protection measures !!
Remote control: We usually have access to those
klystron while running beam, likely need to improve
the remote control capabilities
Questions
A few question to trigger discussions:
1. Timing: How is it organised, beam, controls,
data acquisition
2. Controls: Guidelines for the control system,
hardware, FESA, data base
3. Experiment data taking: which information we
need synchronized, sampling rate (BPM’s
protons, electrons, Laser, spectrometer )?
4. Location of electronics for power supplies,
diagnostics and data acquisition
Rough time line2014 2015 2016 2017
Beam line design
Booster design
Infrastructure definition
Rough Integration
Detailed Component design and fabrication
Detailed integration
Infrastructure installation(Water, Power, Ethernet, klystron handling)
Installation and commissioningIn CTF2(may be not all hardware)
Infrastructure installation, electron source shielding, access system, racks
Installation of source and commissioningin AWAKE
Infrastructure and issues before installation:Water, power, Ethernet, klystron handling equipment, racks for electronics, electron source shielding, access system, laser beam line, alignment concept, commissioning concept, controls
Conclusions
New CERN work package for the electron source in
place
Many open questions we have to address in the
future
Beam requirements for first phase likely possible
with PHIN gun and booster
Some useful equipment should be available from
CTF3
Need detailed beam and laser specifications
Requirements for second phase challenging to fulfil
simultaneously
A lot of work ahead, help is very welcome
Awake electron beam work package reflections
Questions:
Access scenario, where can we go during experiment Location of power supplies, electronics, data acquisition, vacuum
equipment Location of klystron/modulator elements Transport of klystron/modulator items, crane for mounting klystron ? Safety requirements, restrictions Electron source housing, how does it look like Beam diagnostics, what has been done for the beam line yet, BPMs,
correctors Control system, beam, vacuum Water, electricity availability Clarify collaborations, with UK, Frascati ? Define time constraints, milestones