Status of KEK 150MeV FFAG

M. Aiba (KEK)

For KEK FFAG Gr.

FFAG’05, 5 to 9 Dec., KURRI

Contents

Purpose of KEK 150MeV FFAG

Machine Parameters

Hardware　 improvements

Beam extraction and 100Hz operation

Status of accelerator performance

Summary

Purpose of150MeV FFAG

To be a prototype FFAG for various applicationsBeam extraction from FFAG for the first time

Rapid cycling

Test experiments for applications using extracted beam

Machine parameters

Lattice Triplet (DFD)Number of sector 12

k-value 7.6Energy (MeV) 12→ 150 (10→ 125)

Average radius(m) 4.47→ 5.20Betatron tune Hor.: 3.69～3.80

Ver.: 1.14～1.30

Maximum field (T) F: 1.63(on orbit) D: 0.78

Ion source of injector cyclotronHardware improvement (1)

Ion source: DC operation Pulsed operation

Cyclotron RF

Ion source

DC operation

Pulsed operation

Cyclotron RF

Ion source

Beam from cyclotron~200sec

~10secReduce unavailable beam (injection period of FFAG is few sec)Increase peak current 3~4times

Beam from cyclotron

RF systemHardware improvement (2)

Enhancement of RF system:

RF voltage: ~5kVpp ~12kVpp

Anode PS 55kW max. 300kW max.Vacuume tubeof main amp. 4CW25000A 4CW150000E

Drive mechanism for insertionsHardware improvement (3)

Attach drive mechanism toinjection septuminjection bumpsextraction kickerextraction septum

Extraction Septum

Position and angle can be changed while keeping vacuum.

Beam extraction

Fast extraction with kicker and septum

Realize 100% extraction efficiency

Top and side drawings of the septum magnet

Beam extraction experiment(1)Beam separation with kicker

0

0.05

0.1

0.15

0.2

0.25

0.3

5025 5030 5035 5040 5045 5050

Position [mm]

Sign

al [-

]

051026- 03t.wfm

O

Circulating beamSeparated beamwith kicker

0 30 60 90 120 150 180 210 240

- 40

- 30

- 20

- 10

0

10

20

30

40Kicker: main- 460Gauss, sub- 0Gauss

Del

ta_r

(m

m)

Theta (deg.)

Displacement of beam orbit by kicker (calculation)

Kicker

SeptumObservation

5mm*Septum field is not included in this calculation.

Beam extraction experiment(2)Experiment set up

Status of accelerator performance

First goal of accelerator developmentBeam energy: 100MeV

Rapid cycling: 100Hz

Beam current: 1nA

Status, Dec. 2005 Beam energy of100MeV has been achieved. 100Hz operation was successful. Beam current is more than 0.2nA@20Hz operation.

Basic accelerator R&D studies (design, construction, beam injection, acceleration and extraction) has been completed.

Summary

Many improvements since FFAG’04, KEK

Basic accelerator R&D studies has been completed.

First goal will be achieved soon.

Near future plan

Test experiments using the extracted beam

For medical application,

For ADS.