Comb beam for particle-driven plasma

Comb beam for particle-driven
plasma-based accelerators
A.  Mostacci,
on behalf of the SPARC team
Comb beams are sub-picosecond, high-brightness electron bunch trains generated via
the velocity bunching technique. Such bunch trains can be used to drive tunable and
narrow band THz sources, FELs and plasma wake field accelerators. In this paper we
present recent results at SPARC_LAB on the generation of comb beams for particledriven plasma-based accelerators.
Trieste 23-27 Settembre 2013
Comb beam for particle-driven plasma-based accelerators
Novel schemes for plasma based accelerators relies on high brightness beams (high
current, low emittance). Recent and forthcoming technological upgrades have made
SPARC a unique test bench for R&D on high brightness electron beam and their
applications, other than SASE FEL activity already assessed.
Resonant plasma Oscillations by Multiple electron Bunches.
Generation of sub-ps, high brightness electron bunch trains (COMB beam).
Successful generation of COMB beams (measurements).
Numerical simulations for better understanding of the properties of COMB beams
and investigating their application to particle-driven plasma based accelerators.
Comb beam for particle-driven
plasma-based accelerators
Andrea Mostacci
(Sapienza University, INFN-Roma 1)
Coherent (resonant) plasma Oscillations by Multiple electron Bunches
•  Weak blowout regime with resonant amplification of plasma wave by a train of
high Brightness electron bunches produced by Laser Comb technique ==> 5 GV/m
with a train of 3 bunches, 100 pC/bunch, 50 µm long, 20 µm spot size, in a plasma
of density 1022 e-/m3 at λp=300 µm
•  Ramped bunch train configuration to enhance transformer ratio
•  High quality bunch preservation during acceleration and transport
See also
F. Massimo, Transformer ratio studies for PWFA, Tuesday 24-09.
A.R. Rossi, Plasma accelerators: external injection, Wednesday 25-09.
Comb beam for particle-driven
plasma-based accelerators
Andrea Mostacci
(Sapienza University, INFN-Roma 1)
M. Boscolo, M. Ferrario et al., NIM A 577, 409-416 (2007)
Comb beam for particle-driven
plasma-based accelerators
Andrea Mostacci
(Sapienza University, INFN-Roma 1)
Gun focusing field (~3kG)
Emittance
Bunches current, length
Inj. phase
Bunch spacing
Train length
Accelerating field phase
Energy separation
TW focusing field (~300G)
Emittance
Bunches current, length and
their max compression phase
Gun exit energy
Beam brightness
Compression phase
stability
Bunch separation
stability
Gun inj. phase and
space charge
Bunches distance at
the linac entrance
Comb beam for particle-driven
plasma-based accelerators
Andrea Mostacci
(Sapienza University, INFN-Roma 1)
Comb beam for particle-driven
plasma-based accelerators
Andrea Mostacci
(Sapienza University, INFN-Roma 1)
Over-compression
180 deg<φ<90 deg
Compression
φ<90 deg
Deep over-compression
φ>180 deg
TSTEP simulation by C. Ronsivalle
Comb beam for particle-driven
plasma-based accelerators
Andrea Mostacci
(Sapienza University, INFN-Roma 1)
MEASUREMENT
Over-compression
180 deg<φ<90TSTEP
deg
Compression
φ<90 deg
Deep over-compression
φ>180 deg
TSTEP simulation by C. Ronsivalle
Comb beam for particle-driven
plasma-based accelerators
Andrea Mostacci
(Sapienza University, INFN-Roma 1)
Over-compression
180 deg<φ<90 deg
Compression
φ<90 deg
Deep over-compression
φ>180 deg
MEASUREMENT
TSTEP
TSTEP simulation by C. Ronsivalle
Comb beam for particle-driven
plasma-based accelerators
Andrea Mostacci
(Sapienza University, INFN-Roma 1)
MEASUREMENT
Over-compression
TSTEP
180 deg<φ<90
deg
Compression
φ<90 deg
Deep over-compression
φ>180 deg
TSTEP simulation by C. Ronsivalle
Comb beam for particle-driven
plasma-based accelerators
Andrea Mostacci
(Sapienza University, INFN-Roma 1)
Measurements with 200pC
Gun energy
5.7MeV
Charge
40pC/80pC/50pC/30pC
Energy
168-109 MeV
Energy Spread
<0.8%
Bunch length on crest
2126.3 (8.7) fs
Min. bunch length
168.2 (8.7) fs
Gun ext. phase
35 deg
Comb beam for particle-driven
plasma-based accelerators
Andrea Mostacci
(Sapienza University, INFN-Roma 1)
C. Ronsivalle, TSTEP simulations.
Comb beam for particle-driven
plasma-based accelerators
Andrea Mostacci
(Sapienza University, INFN-Roma 1)
C. Ronsivalle, TSTEP simulations.
Comb beam for particle-driven
plasma-based accelerators
Andrea Mostacci
(Sapienza University, INFN-Roma 1)
Deep
over compression
Over compression
Compression
C. Ronsivalle, TSTEP simulations.
Comb beam for particle-driven
plasma-based accelerators
Andrea Mostacci
(Sapienza University, INFN-Roma 1)
Deep
over compression
Over compression
Compression
C. Ronsivalle, TSTEP simulations.
Comb beam for particle-driven
plasma-based accelerators
Andrea Mostacci
(Sapienza University, INFN-Roma 1)
The injection phase in the compressor (RF compressor phase) can select the number
of bunches and their relative current.
Selection of the
Tuning of the relative
Modulation in the bunch
number of pulses
amplitude and separation
Deep
over compression
Over compression
4p
3p
2p
Compression
1p
C. Ronsivalle, TSTEP simulations.
Comb beam for particle-driven
plasma-based accelerators
Andrea Mostacci
(Sapienza University, INFN-Roma 1)
The injection phase in the compressor (RF compressor phase) can select the number
of bunches and their relative current.
Selection of the
Tuning of the relative
Modulation in the bunch
number of pulses
amplitude and separation
Deep RF comp. phase
-89.5 deg
over compression
Over compression
4p
3p
2p
Compression
1p
C. Ronsivalle, TSTEP simulations.
Comb beam for particle-driven
plasma-based accelerators
Andrea Mostacci
(Sapienza University, INFN-Roma 1)
The injection phase in the compressor (RF compressor phase) can select the number
of bunches and their relative current.
Selection of the
Tuning of the relative
Modulation in the bunch
number
of
pulses
amplitude
and
separation
RF comp. phase
Deep -91.5 deg
over compression
Over compression
4p
3p
2p
Compression
1p
C. Ronsivalle, TSTEP simulations.
Comb beam for particle-driven
plasma-based accelerators
Andrea Mostacci
(Sapienza University, INFN-Roma 1)
The injection phase in the compressor (RF compressor phase) can select the number
of bunches and their relative current.
Selection of the
Tuning of the relative
Modulation in the bunch
number of pulses
amplitude and separation
Deep
over compression
Over compression
4p
3p
2p
Compression
1p
RF comp. phase
-93.5 deg
C. Ronsivalle, TSTEP simulations.
Comb beam for particle-driven
plasma-based accelerators
Andrea Mostacci
(Sapienza University, INFN-Roma 1)
The injection phase in the compressor (RF compressor phase) can select the number
of bunches and their relative current.
Selection of the
Tuning of the relative
Modulation in the bunch
number of pulses
amplitude and separation
Deep
over compression
Over compression
Compression
4p
3p
2p
1p
RF comp. phase
-96.5 deg
C. Ronsivalle, TSTEP simulations.
Comb beam for particle-driven
plasma-based accelerators
Andrea Mostacci
(Sapienza University, INFN-Roma 1)
The injection phase in the compressor (RF compressor phase) can select the number
of bunches and their relative current.
Selection of the
Tuning of the relative
Modulation in the bunch
number of pulses
amplitude and separation
Deep
over compression
Over compression
4p
3p
2p
Compression
1p
RF comp. phase -105.5 deg
C. Ronsivalle, TSTEP simulations.
Comb beam for particle-driven
plasma-based accelerators
Andrea Mostacci
(Sapienza University, INFN-Roma 1)
THz radiation source
Measurements,
4 pulses, 200pC
E. Chiadroni,
Linac-based THz radiation sources,
Tuesday 24-09.
E. Chiadroni et al., Rev. Sci.
Instrum. 84, 022703 (2013)
Two color FEL radiation
F. Villa,
Two Colors FEL experiment at SPARC_LAB,
Tuesday 24-09.
Measurements,
2 pulses, 160pC
V. Petrillo et al., Phys. Rev. Lett.
111, 114802 (2013).
Beam diagnostics
R. Pompili, Single-shot longitudinal not intercepting diagnostic (EOS), Wednesday 25-09.
L. Innocenti, A. Cianchi, Measurement of TWISS parameters for COMB beams.
Low level RF system
M. Bellaveglia, fs synchronization systems for advanced accelerator applications, Thursday 26-09.
Comb beam for particle-driven
plasma-based accelerators
Andrea Mostacci
(Sapienza University, INFN-Roma 1)
C_Band
driver
See D. Alesini,
High-gradient C-band
accelerating structures,
Wednesday 25-09.
THz
Radiation
Velocity Bunching
LWFA_ext
THz Radiation
LASER
COMB
See A. Cianchi,
Advanced beam dynamics
experimental studies and
applications at SPARC_LAB,
Wednesday 25-09.
PWFA
DWFA
FEL
Thomson
FEL Single
Spike
Comb beam for particle-driven
plasma-based accelerators
Andrea Mostacci
(Sapienza University, INFN-Roma 1)
Thank
you
Comb beam for particle-driven
plasma-based accelerators
Andrea Mostacci
(Sapienza University, INFN-Roma 1)