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Plasma acceleration experiments at PITZ
Osip Lishilin Laplas-2018, 2018-01-30, Moscow
Plasma acceleration experiments at PITZ Osip Lishilin Laplas-2018, - - PowerPoint PPT Presentation
Plasma acceleration experiments at PITZ Osip Lishilin Laplas-2018, - - PowerPoint PPT Presentation
Plasma acceleration experiments at PITZ Osip Lishilin Laplas-2018, 2018-01-30, Moscow PITZ facility PITZ facility Flexible photocathode laser system Arbitrary longitudinal pulse shape Up to 24 ps FWHM long, 2 ps fronts
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PITZ facility
| Plasma acceleration experiments at PITZ | Osip Lishilin | 2018-01-31
- Flexible photocathode laser system
- Arbitrary longitudinal pulse shape
- Up to 24 ps FWHM long, 2 ps fronts
- Electron beam momentum up to 25 MeV/c
after Booster
- Electron beam charge up to 5 nC
- Longitudinal phase space measurement
employing a transverse deflecting cavity (TDS) and a dipole spectrometer. Temporal resolution up to 0.3 ps, momentum resolution up to 10 keV/c
Free pulse shaping
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Beamline upgrades
| Plasma acceleration experiments at PITZ | Osip Lishilin | 2018-01-31
Electron Beam Plasma cell Dipole Quad 1…4 Quad 5…6 Quad 7…8
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Plasma sources
Lithium plasma cell Gas discharge plasma cell
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Cross-shaped heat pipe oven plasma cell
| Plasma acceleration experiments at PITZ | Osip Lishilin | 2018-01-31
Design: Gerald Koss
2nd generation
Thermal Insulation Cooling Sleeve Electron Window Buffer Gas Distribution Heating Coils
e-
Ionization Laser Path
Gas loaded heat pipe principle
Li Ar Ar z
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Heat pipe plasma cell: ionization laser
| Plasma acceleration experiments at PITZ | Osip Lishilin | 2018-01-31
and its transport
- Coherent COMPexPro 201: ArF
Excimer Laser, 193 nm, up to 400 mJ / pulse, 10 Hz
Optics box
> Side coupling advantage: Well defined and adjustable plasma channel length
- Option: Add filter to implement
density ramps or other plasma profiles
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Lithium plasma cell
| Plasma acceleration experiments at PITZ | Osip Lishilin | 2018-01-31
- Experimental run in 2016: suboptimal buffer gas pressure led to a low plasma
density of 1.3x1014 cm-3 and eventual condensation of lithium in the side arms
- Upcoming run in 2018:
- For the upcoming run heat pipe oven parameters are adjusted -> stable
- peration without condensation issues, measured vapor is density more than
1016 cm-3
- Variable ionization channel length
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Gas discharge plasma cell
| Plasma acceleration experiments at PITZ | Osip Lishilin | 2018-01-31
> ArH2 gas at 0.1 – 10 mbar (sealed off) > 10mm diameter, 100mm length discharge channel > 2-10µs pulses of 200 – 1000A > Plasma densities up to 5x1015 cm-3 > Pre-ionisation via glow discharge
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PWFA experiments
Self-modulation instability High Transformer ratio
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Page 11 | Plasma acceleration experiments at PITZ | Osip Lishilin | 2018-01-31
EAAC Workshop 2013: Patric Muggli, AWAKE: A Proton-Driven Plasma Wakefield Experiment at CERN > High accelerating gradient requires short bunches (z less than 100µm) > Existing proton machines produce long bunches (10cm)
Courtesy: Patric Muggli, Erdem Öz
Self-modulation!
𝐹𝑨,𝑛𝑏𝑦 = 240(𝑁𝑊 𝑛−1) 𝑂 4𝑦1010 0.6 𝑨 𝑛𝑛
2
- Use high energy proton beams from SPS to
drive plasma wave
- Convert proton beam energy to accelerate
electron beam in single stage
Caldwell et al., NIM A (2016)
Caldwell et al., Nature Physics (2009):
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Self-modulation instability (SMI) at PITZ
| Plasma acceleration experiments at PITZ | Osip Lishilin | 2018-01-31
> Study the physics of the self modulation instability > Self-amplified transverse modulation of bunch and coherent wake driving > Studies for proton driven plasma wakefield acceleration (AWAKE, CERN)
Expected measured phase space at 1015 cm-3
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Page 13 | Plasma acceleration experiments at PITZ | Osip Lishilin | 2018-01-31
SMI Experimental Results: 1) Time Resolved Beam
- The first direct time-resolved experimental observation of a self-modulated electron beam
Q=970 pC Plasma density: 1014 cm-3
2016: Lithium plasma cell
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Page 14 | Plasma acceleration experiments at PITZ | Osip Lishilin | 2018-01-31
SMI Experimental Results: 2) Longitudinal Phase space
- Momentum modulation with 200 keV/c amplitude
Q=970 pC Plasma density: 1.3x 1014 cm-3
2016: Lithium plasma cell
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Page 15 | Plasma acceleration experiments at PITZ | Osip Lishilin | 2018-01-31
SMI Experimental Results 3): Self-Modulation vs plasma density
- Measured time resolved electron bunch for different delays of the electron bunch arrival
time relative to the ionization laser pulse
- Paper submitted to PRL
2016: Lithium plasma cell
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SMI Experimental Results 4): Parameter scan at higher plasma densities
| Plasma acceleration experiments at PITZ | Osip Lishilin | 2018-01-31
- Experiment with higher plasma densities (up to 2x1015 cm-3)
- 2-d parameter scan: main solenoid and charge
- Some scans show more evident signs of self-modulation
- Data is not fully analyzed yet
2017: Gas discharge plasma cell Solenoid current: 380 A Solenoid current: 370 A
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High Transformer Ratio
| Plasma acceleration experiments at PITZ | Osip Lishilin | 2018-01-31
Head E- Fundamental theorem of beamloading: Eacc/Edec < 2 Only true for symm. Bunches Various proposed bunch shapes HTR: E+/ E- > 2 E+ Collinear wakefield acceleration (linear theory):
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HTR measurement method
| Plasma acceleration experiments at PITZ | Osip Lishilin | 2018-01-31
- Time resolved energy measurement (slice energy) on screen
- YAG screen for high charge driver maximum loss in driver
- LYSO screen for low charge witness Increase of maximum energy of witness
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HTR measurement
| Plasma acceleration experiments at PITZ | Osip Lishilin | 2018-01-31
- Measured High Transformer ratio up to ~5.3
- Stable only in low density plasma, <5x1013 cm-3
- 508 pC driver, 10 pC witness
- Paper is in preparation
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Laboratory Astrophysics
| Plasma acceleration experiments at PITZ | Osip Lishilin | 2018-01-31
- Bell‘s instability: Amplification of magnetic fields in a plasma, induced by cosmic rays
- Idea: find parameter scaling so that astrophysical phenomena can be investigated in the
laboratory, using PITZ beam and plasma source
- Extensive simulation study is ongoing
- Challenging, but no “show stoppers” found yet
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Conclusions
| Plasma acceleration experiments at PITZ | Osip Lishilin | 2018-01-31
- Two plasma sources are commissioned
- First time resolved measurements of the Self-modulation instability
- Advanced measurements in 2018
- Transformer ratio >5 is demonstrated
- Investigations for lab astrophysics are ongoing
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Thank you for your attention!
| Plasma acceleration experiments at PITZ | Osip Lishilin | 2018-01-31
Plasma team @ PITZ: M. Gross, G. Loisch, O. Lishilin, G. Koss, S. Philipp,
- S. Maschmann
Former members: G. Pathak, J. Engel, P. Weidemann, M. Schinkel, V. Wohlfarth,
- R. Schuetze
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Backup
| Plasma acceleration experiments at PITZ | Osip Lishilin | 2018-01-31
SMI based density measurements
> Density calculation from SMI induced patterns in transverse / longit. phase space > Density measurement at exact point (& time) of bunch passage > Spectroscopic benchmark measurements under preparation > Simulations show errors <10% Fourier spectrum
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Backup
| Plasma acceleration experiments at PITZ | Osip Lishilin | 2018-01-31
HTR definition
> No direct field measurement > No controlled injection of witness bunch (witnessing wide phase range) > Measuring & simulating “effective Transformer Ratio“: Eslice_max, witness, Plasma On – Eslice_max, witness, Plasma Off max( E(mean-slice-energy), driver, Plasma Off – E(mean-slice-energy), driver, Plasma On ) > Worst case underestimating TR: highest energy witness electrons with plasma not necessarily at highest energy without plasma
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Backup
| Plasma acceleration experiments at PITZ | Osip Lishilin | 2018-01-31
Simulations (ASTRA and HiPACE)