Plasma Acceleration R&D
Transcript of Plasma Acceleration R&D
Plasma Acceleration R&D at DESY and University Hamburg
Ralph W. Aßmann Leading Scientist, DESY
02.09.2013
Acknowledge discussions with and/or material from:
R. Brinkmann, H. Schlarb, J. Osterhoff, E. Elsen, F. Grüner, K. Flöttmann, B. Hidding, B. Zeitler, F. Stephan, M. Gross, A. Maier,
…
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Who and What are We? DESY – Hamburg – Zeuthen – University Hamburg –
Helmholtz – ARD – LAOLA – CFEL – REGAE – FlashForward – SINBAD – EuroNNAc – LUX – Angus – etc…
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Helmholtz ARD Programm – Accelerator R&D as a Research Field
> The Helmholtz association distributes research budget from the federal German government to the big German research centers (physics, medicine, biology, computing, climate, chemistry, ...)
> The Helmholtz-ARD program:
> Significant, stable funding (base budget) for acce-lerator R&D independent of big science projects. Coordinator: Reinhard Brinkmann
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Helmholtz ARD – Research Topics and DESY Involvement
Superconducting RF Technology
Concepts and Techno-‐logies for Hadron Acc.
ps – fs Electron and Photon Beams
Novel Acceleration Concepts
ACCELERATOR Research & Development
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DESY base ARD budget 2014 – 2019: > 25 M€ (not full cost)
Add. funding requested from EU and later Helmholtz (strategic invest.).
Very important for us:
Not just national but also international networking!
Example: EuroNNAc = European Network for Novel Accelerators
Fully open for international collaboration.
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è EAAC 2013 in Elba, Italy
Elba 2013
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ARD and LAOLA in Hamburg
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FLASHForward
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LAOLA: Collaboration for Plasma Acceleration
Wismar, Germany, 2012
= DESY Hamburg + DESY Zeuthen/Berlin + Uni Hamburg + Friends
DESY Hamburg
University Hamburg
DESY Zeuthen
Supporting institutes.
LAOLA Board R. Aßmann (co-chair) R. Brinkmann (DESY directorate) E. Elsen (link particle physics) K. Flöttmann (PL REGAE) B. Foster (Head VI) F. Grüner (speaker) B. Hidding (PL trojan horse) A. Maier (scientific secretary) J. Osterhoff (PL FLASHforward) B. Schmidt (co-chair) F. Stephan (PL LAOLA@PITZ) Decision body. Meeting every two weeks with minutes and action list for follow-up.
LAOLA Technical B. Hidding (co-chair) J. Osterhoff (co-chair) All collaboration members invited.
Technical discussion meeting. Should take place every 2 weeks.
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LAOLA: Related Projects and Schedule
10
2012 2013 2014 2015 2016 2017 2018
FACET E-210: TROJAN
LUX: LWFA driven undulator & FEL
lase
r driv
en
beam
driv
en
SINBAD: ARD distributed facility at DESY
preparation installation operation
REGAE: low energy injection
PITZ: self-modulation & high transformer ratio
FLASHForward: high energy injection, Trojan horse
….
….
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One Focus: External Injection of Known Beams...
> Stability in plasma accelerators still insufficient. At the same time no fundamental limit on stability is know.
> § A known e-beam is
injected à .
§ DESY „Best in Class“ accelerator + laser + plasma.
§ Reduced complexity!
§ Allows placing several accelerating plasma structures behind each other (“Staging”).
> Probably requires correction of correlated energy spread.
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Why Can DESY Contribute as ”Newcomer“?
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DESY “femto-second” Beam Expertise as
Enabling Technology
H. Schlarb, EuCARD2, CERN, WP13, 14.06.2013
FLASH layout > Fixed gap SASE undulators
315 m"
Bunch Compressor"
SASE Undulators"sFLASH"
Bunch Compressor"
5 MeV" 150 MeV" 450 MeV" 1250 MeV"
Accelerating Structures"
FEL Experiments"
RF stations"
RF Gun"
> TESLA type superconducting accelerating modules (1.3 GHz) > 3rd harmonic module (3.9 GHz )
> Diagnostics and matching > Normal conducting 1.3 GHz RF gun
> Ce2Te cathode
> Nd:YLF based ps photocathode laser
> Variable gap sFLASH undulators > FEL Experimental Hall
> FEL Experimental Hall
H. Schlarb, EuCARD2, CERN, WP13, 14.06.2013
Sources of timing jitter in short-pulse accelerators
RF gun" Accelerator"Undulator/ Plasma cell
γ
bunch compressor" Main Linac"
Photo-cathode"laser"
Pump-probe"laser"
Sources of timing jitter (uncorrelated): σt = [Σ (w σt,I)2 ]1/2
Photo-cathode laser w < 5% RF phase of RF gun (non-relativistic electrons) w < 5% Seed / Pump-probe laser / LWA Laser w ~ 100% RF amplitude and phase w ~ 100%
Seed"laser"
Timing jitter behind BC
Voltage
XFEL: 3.3 ps/% FLASH: 5.5ps/%
2 ps/deg L-band
0.05 ps/ps C=20
Phase Incoming compression factor C ~5 … 20
A/φ
Arrival time jitter at undulator / plasma cell (single stage)
R56=180mm
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Control of timing jitter: fs-synchronization & RF controls & Beam based FB
H. Schlarb, EuCARD2, CERN, WP13, 14.06.2013
RF control of long RF pulses (SRF) 16
ADC boards LL
RF
CTR
L
POW
ER
MO
DU
L
E M
CH
CPU
Tim
ing
> MTCA.4 Shelf: FLASH/E-XFEL > Keeping cables short
> E-stability (SR-3DBC2)
800us
Energy stability dE/E = 5E-5.
1 RF station, 8 cav.
> New features obs. Single 1nC bunch transients
7/9-pi mode instabl.
> FLASH operation:
ACC23 in accelerator tunnel ACC23 LLRF racks
H. Schlarb, EuCARD2, CERN, WP13, 14.06.2013
RF control of long RF pulses (SRF) 17
ADC boards LL
RF
CTR
L
POW
ER
MO
DU
L
E M
CH
CPU
Tim
ing
> MTCA.4 Shelf: FLASH/E-XFEL > Keeping cables short
> E-stability (SR-3DBC2)
800us
Energy stability dE/E = 5E-5.
1 RF station, 8 cav.
> New features obs. Single 1nC bunch transients
7/9-pi mode instabl.
> FLASH operation:
ACC23 in accelerator tunnel ACC23 LLRF racks
Approach for dA/A ~ 0.001% and ~ 0.001 deg
many new effects have to be taken into account
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The Exploratory Phase: Experiments at REGAE, FLASH
and PITZ
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J. Osterhoff et al, see also talk by J. Dale
Ralph Aßmann | LPAW2013 | 02.09.2013 | Page 25 J. Osterhoff et al, see also talk by J. Dale
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J. Osterhoff et al, see also talk by J. Dale
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J. Osterhoff et al, see also talk by J. Dale
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J. Osterhoff et al, see also talk by J. Dale
Hybrid LWFA/PWFA: PWFA has fundamental advantages compared to LWFA: no dephasing, particle beam expansion much less of an issue than laser beam diffraction, unipolar e-beam field orders of magnitude lower when compared to oscillating fields of Ti:Sapph lasers But: suitable electron drivers require conventional accelerator, not easily available ⇒ Use electron beams from LWFA as drivers in subsequent PWFA stage! Hidding et al., PRL 104, 195002, 2010. Various PoC experiments in preparation.
Prof. Bernhard Hidding Plasma accel. core activities, LPAW 2013
scapa.ac.uk hybrids.desy.de laola.desy.de
laser diffraction vs . beam expansion:
LWFA bubble
PWFA blowout
Underdense photocathode PWFA (aka Trojan Horse): Hybrid system with PWFA blowout based on low-ionization-threshold (HIT) medium such as hydrogen, and strongly focused low-intensity laser pulses which release higher-ionization-threshold (LIT) medium (such as He) electrons inside the blowout either in co-propagating geometry or at an arbitrary angle [1-4]: Hidding et al., PRL 104, 195002, 2010
Prof. Bernhard Hidding Plasma accel. core activities, LPAW 2013
scapa.ac.uk hybrids.desy.de laola.desy.de
• Key enabling principle: plasma blowout is generated with extremely low peak E-fields, subsequent laser pulse can have low intensity & electric fields to liberate further electrons with low transverse momentum
• enormous controllability and flexibility (e.g. use higher release laser frequencies)
• allows extremely small emittance εn down to 10-10 m rad and enormous brightness B = 2 I/εn
2 > 1019 A rad-2 m-2
• ⇒ ideal candidates for light source drivers such as FEL
Proof-of-concept experiments at FACET 2014, FlashForward 2016, hybrid laser-plasma-accelerators, SINBAD..
[1] German/US/PCT patents AZ 10 2011 104 858.1, 2011,PCT/US2012/043002, 2012 [2] Hidding et al., PRL 108, 035001, 2012 [3] Hidding et al., AIP Conf. Proc. 1507, 2012 [4] Xi et al., PRSTAB 16, 031303, 2013
Space radiation reproduction and testing of electronics: Radiation in space can harm electronics as well as astronauts onboard of space vessels, and is a main showstopper for space exploration. So far, linacs & cyclotrons are used for ground-based testing, but these produce strictly monoenergetic beams, whereas radiation in space is always broadband, often exponential, and power-law type. Such broadband flux is the realm of laser-plasma-accelerators! Laser-plasma-acceleration for space radiation reproduction with underdense and overdense targets was introduced [1-3] and proof-of-concept experiments have recently been conducted successfully in cooperation with European Space Agency.
Prof. Bernhard Hidding Plasma accel. core activities, LPAW 2013
scapa.ac.uk hybrids.desy.de laola.desy.de
[1] German/US patents AZ 10 2010 010 716.6, 2010, US 13/042,738, 2011 [2] Hidding et al., NIM A, Vol. 636, 1, 2011 [3] Königstein et al., JPP 78, 4,2012
Van-Allen belt “Killer electrons” flux has been produced from LWFA w/ solid targets (using the Arcturus 150+ TW laser in Düsseldorf), and space-grade optocouplers provided by ESA were irradiated and showed significant performance degradation.
This is an application for LPAs which has been left behind, high feasibility, opens up industrial exploitation. tbc
Optocoupler shadow on image plates after irradiation with laser-plasma-generated electron flux
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LAOLA@PITZ: The Plasma Exp. In DESY/Zeuthen – Berlin
Electron Beam
Design: Gerald Koss
Plasma cell windows
Preliminary Version
Screen stations
Quadru- poles
Plasma cell
Laser in
Laser out
1 meter
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LAOLA@PITZ Goals
> Self-modulation of a long e- bunch in a plasma cell. § Micro-bunching. Instabilities. Seeding.
> Metal vapor plasma cell design. § Plasma to vacuum UHV transition without windows (low energy beam).
§ Reliable beam steering into plasma channel.
> High transformer ratio with bunch shaping.
> Multiple bunch driving plasma wakefield. § Requires installation of required bunch compressor.
§ Resonant beam driving with optimized photo injector.
> Lessons for CERN experiment AWAKE?!
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Experiments have started with Plasma Cell Prototype
Temperature probe with measurement
Power supply for heater
Plasma cell with heat insulation
> First: Measurement of temperature profile with air in plasma cell tube
> Copper tube helps to homogenize temperature distribution: ±2°C (<1%) over 10cm
> Temperature is high enough: need ≈650°C in PITZ experiment
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The Targeted R&D Phase: Converting a Collider and Photon Science Accelerator into one Leg of an ARD Test Facility – Building
the Plasma Accelerator
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Helmholtz Roadmap
> The latest Helmholtz-roadmap for research infrastructure was published in 2011.
> This roadmap calls for a Distributed ARD Test Facility.
> This would be a joined proposal in 2016 by several Helmholtz centers for infrastructures at these labs.
> Total construction cost as listed: 40 M€. To be spent in a distributed way…
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DESY: DORIS into Accelerator R&D Facility?
Project for atto-second science?
ARD collabora-tion on very short bunches (DESY, Uni HH, KIT, …)
LAOLA-ARD experiments (DESY, Uni HH, …) on staged, ultra-high gradient plasma acceleration
Room for addi-tional experi-ments: the PIER Voss-Wideröe Center will be a forum to call for proposals
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DORIS DESY Laser Laboratory
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( hort novative unches and ccelerators at oris): Phase 1
DESY Laser Laboratory
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“Conventional” 1 GeV Electrons in DORIS?
Excellent integration into DESY accelerator park! 1 GeV allows
, outside of user‘s operation.
PIA allows à needed for collider applications (HEP)! Must address RP aspects in transfer tunnel below building 30.
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Scientific Case SINBAD (on 1 Slide)
> Generating bunches with length < 1 fs, into the atto-second regime: § Conventional photo-injectors with velocity bunching, space charge field, …
(see also Holger Schlarb, FLUTE, …)
§ Towards atto-second science with new technologies
§ Compact light sources
> Prototyping a 1 GeV plasma accelerator unit with industrial quality: , staging, …
(next phase of LAOLA@REGAE type experiment)
§ Best plasma cell technology: different types, UHV compatibility, …
§ Plasma unit with internal injection (replacing 100 MeV linac)
§ Plasma unit with (10 b. low E à 1 b. high E)
> Prototyping applications for plasma accelerators: § Ultra-compact VUV FEL’s
§ Demonstration of plasma linear collider at very low energy
LAO
LA R
elat
ed R
&D
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SINBAD Scenario: Building a 1 GeV Plasma Stage
A. Plasma density ≈ 1014 cm-3 – plasma length ≈ 0.1 m 1) Match a well characterized beam into plasma with
2) Energy gain , match plasma at exit , measure E spread
3) Demonstrate (non-diluted case): transport over , minimize betatron oscillation out of plasma, measure emittance
4) Requires about two π/2 FODO cells before and after plasma, eventually plus matching, diagnostic integrated in FODO cells, plus collimation, correction, …
B. Increase plasma density in steps…
C. …up to final of ≈ 1017 cm-3 – plasma length ≈ 0.1 m: 1) Match a well characterized beam into plasma with beta
2) Energy gain ≈1 GeV, match plasma at exit with beta
3) Demonstrate (fully diluted case): transport over , minimize betatron osc. out of plasma, measure emittance
NOTE: SINBAD is not aimed at new accelerating records but at producing a useable, high quality beam from a plasma accelerator!
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Towards the table-top, really compact accelerator…
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… for high power physicists
Thank you for your
attention!
German chancellor Dr. Angela Merkel with a miniature model of an accelerating structure during her 2012 visit to DESY, with Prof. Dr. Helmut Dosch (DESY director)
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The end…
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EAAC 2013