Present status of Energy Recovery
Linac (ERL) project
H. Kawata
ERL Project Office, KEK
Photon Factory, KEKPlan for Future Light Source
Scientific requirement
Continuation(precise analysis)
1) nano-structure3) non-crystalline materials

mmbeam size :nm2) electronic states
ΔE :Jump(cutting-edge science)

1meV

coherency
4) non-equilibrium states

0.1meVHigh brilliant light source

sub-pico second pulse

Coherence and short pulse

Energy Recovery Linac(ERL) is the mostpromising for future light source◎ Linac based light source: 2~3 orders of magnitude!
1) Emittance ： 10pmrad（3rd generation source ： ~10nmrad)

2) Short pulse : 0.1~1 pico-second (3rd generation source : ~0.1nano-second)◎ A large numbers of ID-beamlines

Why 5GeV ERL for Future Light Source?
•Performances
The brilliance and pulse width are 2 orders of magnitude brighter andshorter than those of 3rd generation synchrotron radiation facilities.
(Option): XFEL-O: K.-J. Kim, Y. Shvyd’ko, S. Reiche, PRL. 100, 244802 (2008).

•Scientific Cases
Coherency
Atomic and nanoscale imaging (Cells and Viruses, Nano-materials etc.)
Femto-second science
Real-time reaction which requires high repetition rate.
(Chemical reaction, Photo-inused phase transition etc.)
Nano beam
Condensed matter physics under extreme conditions.

• A challenging machine• A great potential of KEK to develop the ERL accelerator(superconducting technology, nano-beam technology)

Grand challenges for basic sciences
˜ Non-crystalline materials and nano-science ˜Function in a cell

Catalysis chemistry

biologyandchemistry

Nano beam

D. Shapiro et. al. PNAS,102, (2005)

Nano-materials
at interface(c)Sr Ti O
2+4+3

La3+Ti3+O3

Formation of(LaO)2 layers

La3+Ti3~4+O3+d4 nm
A. Ohtomo et al.
Appl. Phys. Lett. 80, 3922 (2002)

Extreme conditionmaterials,energy
andenvironment

Grand challenges for basic sciences
˜ Non-equilibrium states generated by photons ˜
photosynthesis

visual sensing

biologyandchemistry
ultrafast
photo-switchingmaterials,
energyandenvironment

solar cellComparison between ERL and SASE-FEL
as a future light source

SASE-FEL

ERL

averagebrilliancepeak
brilliance

repetition
rate (Hz)

coherentfraction

bunchwidth(ps)# ofBLs

Remark~1023~1026

1.3G~20%0.1~1~30

Non-perturbed
measurement

SASEFE~1022~23
L~1033100~1K100%

0.1~1One-shotmeasurement~1033~1M

100%

1few

Single mode
FEL

ERL

XFEL-O（Option)~1027(brilliance : photons/mm2/mrad2/0.1%/s @ 10 keV)Is it possible to construct 5GeV-ERLin Tsukuba campus?
5GeV-ERL

PF-ARPF

5GeV-ERL light source will
be one of the most important
accelerator facilities atTsukuba campus in a future.

Structure of the ERL Project Office
Collaboration with
Other ERL Projects(Cornell)

ERL Project teamKEK
ERL Project TeamWG-1
ERL WG-2
Project WG-3
・Office ・WG-X

ISSP, AIST
OtherFacilities

JAEA

Development of the accelerator components
Super conducting cavity
for pre-accelerator

LatticeSuper conducting cavity
for main accelerator
•••
•••
•
•

Electron gun

Super conduction cavity for main accelerator (KEK, ISSP, JAEA)(37MV/m`Single cell model ⇒ 9 cell model ⇒ Cryo-module will be designed from the next
fiscal year）
Electron gun (JAEA, Hiroshima Univ., KEK, and Nagoya Univ.) (construction ofelectron gun of 250 kV and we start the designing of the electron gun of 500kV)

Development of the laser system for electron gun (AIST, ISSP, KEK)
(Yb fiber laser of ~100MHz oscillator ⇒ 1.3GHz oscillator)
Development for the super conducting cavity of pre-accelerator (KEK)(Test cavities have been completed.)
Start the development of high power RF source(300 kW Klystron will be ready until the next summer)
Designing of the cryogenic systems (KEK)
Designing of the lattice (KEK, ISSP, UV-SOR, JAEA)CDR of Compact ERL has been published at March 2008

Evolution of ERL
Development of keycomponentsFuture light source

Compact ERL〜2013

5GeV-ERL~60 MeV

2013〜
Coherent SR at THz region
Hard X-ray (-10keV) bylaser inversed Comptonscattering

Spread of the advanced compact Xray imaging sources to hospitals

Compact ERL
PS East Expt. Hall

key components
・ DC photocathode gun
・ 1.3GHz CW laser・ Superconducting cavities
・ Beam dynamics

Scientific Case
CSR at THz region
high intensity by order of 6-7
compared with conventional source

Hard X-ray by laser inversed
Compton scattering
・ extremely small beam
⇒ e.g. medical imaging
・ fs scienceTime Schedule of the ERL Project
2006

2007

2008

2009

2010

2011

2012

2013

2014

2015

Compact ERL
DesignDevelopmentof key
components
Construction
Commissioning
User operation
5GeV ERL
DesignConstruction1)Construction of a ~60 MeV class Compact ERL
2) Demonstration of the principle of the ERL until the end of2012.
3) We hope to start construction of 5 GeV class ERL from ~2013.

Summary• ERL project has been progressed under the collaboration with KEK,JAEA, ISSP, AIST, CHESS and other facilities.
• To resolve technical & physical challenges and demonstrate thecharacteristic scientific cases on ERL, the Compact ERL is underconstruction.
• The Compact ERL will consist of a 5-MeV injector, 1-2
cryomodules, a return loop and a beam dump. The energy will be 60200 MeV.
• R&D for the DC photocathode gun and for the SC cavities havebeen progressed.
• CDR of Compact ERL has been published at March 2008
• Funding to develop the advanced accelerator technology (basictechnology for ILC and ERL) from this fiscal year.