accelerator design and construction for ffag-kuca adsr

Accelerator Design andConstruction for

FFAG-KUCA　 ADSR

Y.Ishi Mitsubishi Electric Corp.Oct. 15 2004

ADSRAccelerator Driven Subcritical Reactor

charged particle

accelerator

subcritical reactor

target for generating neutron

Beam off chain reaction stopsSafer system !

FFAG for ADSRAccelerators should have high power efficiency

Pbeam / Ploss > 30%

FFAG (B~rk)

• Fixed field -extremely high rep. rate(1kHz) high intensity

-superconducting magnet small Ploss

• Alternating gradient

-compact size

ADSR in Kyoto University Research Reactor Institute(KURRI)

Feasibility study of ADSR

Five-year program 2002 – 2006

Subject1. Accelerator technology -variable energy FFAG 2. Reactor technology -basic experiments for energy dependence

of the reactor physics ( need ~10nA)

Beam specifications

Beam species

Energy

Average beam current

Rep. rate

H ＋

150MeV

1A

120Hz

H ＋

200MeV

100A

１ kHz

future upgradebasic experiments

FFAG – KUCA ADSR system schematic diagram

ion source

injector

main ring

KUCA

subcritical reactor

booster

100keV 2.5MeV 20MeV 150MeV

Parameters of the Accelerator Complex

Einj

Eext

Lattice type

Acc. scheme

# of cells

k value

coil/pole

Pext/Pinj

Rinj

Rext

Injector

100keV

2.5MeV

Spiral

Induction

8

2.5

coil

5.00

0.60m

0.99m

Booster

2.5MeV

20MeV

Radial DFD

rf

8

2.5

pole

2.84

1.27m

1.87m

Main ring

20MeV

150MeV

Radial DFD

rf

12

7.5

pole

2.83

4.54m

5.12m

Beam intensity schedule

Ion source

Injector inj.

Injector ext.

Booster inj.

Booster ext.

Main ring inj.

Main ring ext.

Scheme

continuous

continuous

12-turn

1-turn

1-turn

1-turn

pulse length

50s

5s

5s

50ns

50ns

65ns

peak current

5mA

-

32mA

-

2.4A

-

1.6A

Efficiency

90%

70%

80%

95%

95%

95%

<I>=1.6A ×65ns ×1kHz = 108A

Layout of the complex

Specifications of the injectoritem

Energy<I>

Rep. ratePulse length

kspiral angle

tuneSize

Weight

(1.85,0.80)

specs

42 degree2.5

MeV２．５μ A０－２

Hz- 1kHz１２０μ s１－５

3500Wx6000Dx2500H３０ｔ

Image view of the injector

Top view of the injector

Top view of the injector

Cross section of the magnet

Tune of the Injector

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

1.5 1.6 1.7 1.8 1.9 2 2.1 2.2 2.3 2.4 2.5

ν ｘ

ν y

model27d

model28

model30

Model of injector magnet

Injector main magnet

Injector main magnet2

Induction accelerationV=d/dt

Duty=(b-a)/s

= （ 1-Va/BS)

V=BS/b

=b/s

High duty

large

B →　 large

S →　 large

Pulse structure of the beam

continuous injection to the injector

compressed pulse from the injector

Vgap=2kV

Vgap=30kV

acc. period spill

5s

acc. Voltageinjection

50s

Acceleration voltage pattern

Induction core

Booster layout

Injection septum magnet

Injection septum

electrode

Injection bump magnet

Injection bump magnet

Injection bump magnet

Extraction kicker magnet

Rf cavity

T （ MeV)

B （ Tm)

k

Vrf(kV)

Rmin(m)

Rmax(m)

frev(MHz)

BF/FD(T)

tune

injection

2.5

0.2286

1.270

1.364

2.595

0.637/0.204

extraction

20

0.6496

1.736

1.865

5.294

1.376/0.462

2.5

1.6 – 3.0

(2.15,1.38)

Specifications of the booster

Lattice structure of the booster

Lattice functions of the booster

K value optimization

K value optimization

Booster main magnet

Cross section of the booster main magnet

Booster tune variation

Specifications of the main ring(the same design as KEK 150MeV)

T （ MeV)

B （ Tm)

k

Rmin(m)

Rmax(m)

frev(MHz)

BF/FD

tune

injection

20

0.6496

4.451

4.633

2.106

0.678/0.398

extraction

150

1.8390

5.023

5.229

4.651

1.699/0.998

7.6

(3.73,1.55)

TOSCA calculation

Main ring main magnet

Main magnet F coil

Main magnet D coil

Main ring vacuum chamber1

Main ring vacuum chamber2

Summary

• Accelerator complex is now under construction

• First beam from FFAG will be injected to subcritical reactor in 2005.