KEK Beam Test Facility
Status and Plans

J. Haba (KEK)
for Fuji Test Beam Line GroupTest beam facility in KEK• Proton Synchrotron (12GeV PS) wasterminated Dec. 2005

Currently, there is no facility in KEK for the R&D efforts
toward SuperB, ILC nor J-PARC experiments….

• J-PARC (Tokai : ~50km from KEK): test beam

will be available not earlier than 2010.
• A new facility, “Fuji Test Beam Line(FTBL)”, is supposed to deliver a beamfrom Fall 2007.

Where FTBL being built?
Fuji XingTsukubaIR12 GeV PS(terminated)
Main Entrance

100 m straight section
for e- 8 GeV

“Turtle” simulation for Bremsstrahlung photon
by T. Higuchi
100mBending Magnet
8GeV e-KEKB tunnel

Bremsstrahlung photons(1.6x106 photons/sec >1GeV)
From 1.3 A electron beam on
residual-gas (3x10-8Pa CO assumed)

3.5GeV e+

Straight section(100m)

Beam chamber at the bend
to be replaced for gamma to exit efficiently

Effective thickness ~5mmt/sin(7゜) (Cu) ~ 3X0
10% photon will come out unconverted.

Photon exit windowTemperature at the exit windowWatercoolingSR~100 C

Slit for gamma
at the existing HER-Q

Slit 10x30

340 off
QX2E.2

QX3E.2

by T. Higuchi

Generated electron
Based on Geant4 simulation+/- 3.5mrad
Energy(GeV)

profile : px/pz (rad)Bending Magnet+)
Bremsstrahlung
photons
Charged particles(e-/efromBeam v.s.
residual-gas
scattering
fromBrems. photon
5 photons/sec(tungsten
converter: 3mm  ~1X0)
1.6x10Straight section(100m)

Converted particles are extracted
Bending Magnet
to outside of KEKB tunnel

Straight section(100m)

Fuji Xing

Bending
MagnetExtraction line components•Aperture•

Beam Line Parameters...

•––––

Bend
Q[1,2]
Q[3,4]
Shield hole––––––

Bend
type
B1L B1S wiggler L+S
B2
BT modelB3
BT modelB4
BT modelB5, 6, 7
wiggler L

B(T)
1.2
1.2
1.2
1.2
1.2

L(cm)
100+50
160
160
160
100x2

PS
A
B
B
B
AW
3400/2000

––––
–

Quad
Q1
Q2
Q3
Q4

Max I
50 A
50-0.276
0.317

L[m]
0.525
0.525
0.584
0.584

Bore[m]
0.052
0.052
0.166
0.166

PS
CCAB–––

Type A: Beam channel 300A55V
Type B: Beam channel 500A33V
Type C: KEKB Vac. Group 60A 35V

PS (Power supply)

Width 80mm (+sagitta 40mm)/ Height 40mm
φ50
φ166
LER spare
φ100

Max B
16 T/m1640.359
27.5053400 each

new
new
new
W
390 kg
390
2070
2070

Delivered Beam

“SAD” simulation
by A. Morita (KEKB)~200 electrons/sec (DC)p = 0.5 ~ 3.4 GeV/c
σp/p ~ 0.4%
spot size +/−1cm+/−1cm

σp/p = 0.4 %θAngular dispersion after converter

P (GeV/c)Beam line stage
constructed in Fuji hallKBKE

ju
Fielishd

Radiation restricted area

Components collected everywhere
Bendingmagnetshutter

Power supply

Most of the magnets,
all the power-supplies
and the beam shutter are
recycled fromthe past experiments

Three new compact magnets to beinstalled under Xing

Designed by Egawa

Fuji Test Beam Line : Schedule
2007
Jan Feb Mar Apr May Jun Jul Aug Sep
KEKB chamber modification
PS testKEKB magnet modification
Field mapping
Floor for exp.

magnets
installationcommissioning

Chamber
replaeUser run

Summer shutdownof KEKB

Run time  KEKB operation

J-PARC Test Beam Line (Phase-1)
Not earlier than 2010 ~,even for option 3.

25 Hz

Summary• New Test Beam Facility in KEK,

“Fuji Test Beam Line (FTBL)”,
will deliver a beam from Sep 2007
• Electron (positron) beamRate ~200 Hz (continuous, no bunch structure)p = 0.5~3.4 GeV/c, dp/p = 0.4%
Conversion of bremsstrahlung photon without
any performance degradation in KEKB

Backupフォトン数見積もり
2

d & 4 - kmax * 4(kmax ' kmin ) (kmax ' kmin ) #N. =ln++('$!
X 0 % 3 , kmin )3E2E 2"212.
5g/cm$ p (atm)!13d=#1"
10X036 g / cm 2for residual gas of CO @ p = 3 "10 !8Pa = 3 "10 !13 atmin 100 m long straight section.

Nγ= 2x10-13 / electron (1~8 GeV/c)
Nelectron(HER=1.3A)= 8.1x1018 (1/sec)

フォトン数＝1.6ｘ１０６ /秒

電子数の見積もり
ビームパイプ取り出し窓厚さ（銅：3 radiation
length を仮定）これによるコンバージョンロスは、•9X c = (X o )7より、3.0／(９／７)＝
２．３３ conversion lengthNγ (NC)= Nγ*exp (-2.33)= 1.6 x105 /秒
TURTLEによるHERビームのシミュレーションにより、Bremsstrahlungの生成、Geant4によりコンバージョン電子の生成を行う。

周辺の現状ステップ・リフターの設置で往来に配慮