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,

…

Ralph Aßmann | LPAW2013 | 02.09.2013 |

Who and What are We? DESY – Hamburg – Zeuthen – University Hamburg –

Helmholtz – ARD – LAOLA – CFEL – REGAE – FlashForward – SINBAD – EuroNNAc – LUX – Angus – etc…


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


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


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.


è EAAC 2013 in Elba, Italy

Elba 2013


ARD and LAOLA in Hamburg


FLASHForward


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.


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

….

….

….


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.


Why Can DESY Contribute as ”Newcomer“?


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


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

15

Control of timing jitter: fs-synchronization & RF controls & Beam based FB


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


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


The Exploratory Phase: Experiments at REGAE, FLASH

and PITZ


J. Osterhoff et al, see also talk by J. Dale

Ralph Aßmann | LPAW2013 | 02.09.2013 | J. Osterhoff et al, see also talk by J. Dale


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



•  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.



[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


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


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?!


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


The Targeted R&D Phase: Converting a Collider and Photon Science Accelerator into one Leg of an ARD Test Facility – Building

the Plasma Accelerator


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…


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


DORIS DESY Laser Laboratory


( hort novative unches and ccelerators at oris): Phase 1

DESY Laser Laboratory


“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.


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


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!


Towards the table-top, really compact accelerator…


… 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)


The end…


EAAC 2013

plasma acceleration r&d

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