cERL周回部真空系の進捗状況

谷本 育律, 本田 融, 野上 隆史, 高井 良太, 帯名 崇
KEK 加速器第七研究系
2013年2月21日 第69回ERL検討会

Outline

1. Design of the cERL Vacuum System
2. Layout of the Vacuum Components
3. Summary of the Progress

1. Design of the cERL Vacuum System

cERL Vacuum System
Low-impedance Vacuum Components- need to be developed to accommodate high current (10~100 mA), lowemittance (0.1~1 mm•mrad), and short pulse (0.1~3 ps) beams- adopt gap-less and step-less structures in ﬂanges, monitors, etc. to reduce
resistive wall wake ﬁelds, aiming at mitigation of BBU and chamber heating
Required Pressure- around SC cavities: 5×10-9 Pa by NEG-coated tubes (coated at ESRF)
to minimize gas condensation on cryo surface- in other regions:
1×10-7 Pa by lumped NEG pumps and sputter ion pumps
to mitigate beam-gas interactions (ion trapping and beam loss)
Ready for In-situ Bakeout- no scrubbing eﬀect expected
Incoherent SR (ISR) power: 2.2 W (125 MeV, 100 mA)
Coherent SR (CSR) power:
77 W (125 MeV, 10 mA, σz = 0.3 mm)- no measures needed against the heat load of SR
adopt stainless steel (AISI 316L) as main material of beam tubes
High-power Beam Dump
- Max power load: initially 60 kW (6 MeV, 10 mA), ﬁnally 600 kW (6 MeV 100 mA)

Dipole ChamberA

Laser Alignment Porte- Beam

A

40

70

NEG Pump

60

A-A

56

SR PortSpecial Flange for cERL

φ114

114

4-Flat Surface

40φ50

70
2-Leak Groove( W 2, D1.2)
2-Leak Groove(R0.2)

2-Leak Groove(R0.1)
2-Leak Groove( W 2, D1.2)

Straight Section(Type A, φ114)

8-φ10 Hole(PCD92.2)

φ118

12-φ10 Hole(PCD100)

Arc Section(Type B, φ118)

Special Flange for cERL(Cu gasket)

Special Flange for cERL
（U-tightseal or Helicoflex）

Special Flange for cERL
（φ114, straight section）

Cu Gasket

U-tightseal or Helicoflex

Good leak tightness - after 180ºC, 24h bakeout, pressure reached 2×10-8 Pa by TMP

Flange Interface

Pin Hole

Screen Monitor (OTR, YAG)

Beam Position Monitor

Movable Beam Dump

Insulator

φ256025

OFHC coppercERL114FH

φ24Beam

φ504040

ICF253FT36060cERL114FH150

ICF203FHx2Movable Beam Dump

Movable Beam Dump

Beam Collimator（Straight Section）

150

Collimator Rod(OFHC Cu)

Cooling Water

ICF034FH

RF Shield

2463

φ114

63φ
ICF034FHcERL114FH

ICF034FHcERL114FH

φ1450

Beam Collimator（Arc Section）

Collimator Rod(OFHC Cu)
ICF034FH

Cooling Water
RF Shield

24

ICF034FH

ICF034FH

φ14cERL Vacuum System
Low-impedance Vacuum Components- need to be developed to accommodate high current (10~100 mA), low emittance(0.1~1 mm•mrad), and short pulse (0.1~3 ps) beams- adopt gap-less and step-less structures in ﬂanges, monitors, etc. to reduce
resistive wall wake ﬁelds, aiming at mitigation of BBU and chamber heating
Required Pressure- around SC cavities: 5×10-9 Pa by NEG-coated tubes (coated at ESRF)
to minimize gas condensation on cryo surface- in other regions:
1×10-7 Pa by lumped NEG pumps and sputter ion pumps
to mitigate beam-gas interactions (ion trapping and beam loss)
Ready for In-situ Bakeout- no scrubbing eﬀect expected
Incoherent SR (ISR) power: 2.2 W (125 MeV, 100 mA)
Coherent SR (CSR) power:
77 W (125 MeV, 10 mA, σz = 0.3 mm)- no measures needed against the heat load of SRadopt stainless steel (AISI 316L) as main material of beam tubes
High-power Beam Dump
- Max power load: initially 60 kW (6 MeV, 10 mA), ﬁnally 600 kW (6 MeV 100 mA)

Calculated Pressure Distribution(without NEG coating)ds = 0.1 m, q = 5x10-9 Pa m3 s-1 m-2-610

Pumping Speed

10-7

101

10-8

100

10-9

10-1

10-10

10-2

10-11

10-3

020SCC40 s (m)ARC16080
ARC2Pumping Speed (m3/s)

Pressure (Pa) & Outgas (Pam3/s)

Pressure
Pav = 5.83E-8 PaOutgas

102

Calculated Pressure Distribution(with NEG coating)ds = 0.1 m, q = 5x10-9 Pa m3 s-1 m-2-6

10

Pumping Speed

10-7

101

10-8

100

10-9

10-1

10-10

10-2

10-11

10-3

020
SCC

40 s (m)
ARC16080
ARC2

Pumping Speed (m3/s)

Pressure (Pa) & Outgas (Pam3/s)

Pressure
Pav = 5.64E-8 Pa
Outgas102

cERL Vacuum System
Low-impedance Vacuum Components- need to be developed to accommodate high current (10~100 mA), low emittance(0.1~1 mm•mrad), and short pulse (0.1~3 ps) beams- adopt gap-less and step-less structures in ﬂanges, monitors, etc. to reduce
resistive wall wake ﬁelds, aiming at mitigation of BBU and chamber heating
Required Pressure- around SC cavities: 5×10-9 Pa by NEG-coated tubes (coated at ESRF)
to minimize gas condensation on cryo surface- in other regions:
1×10-7 Pa by lumped NEG pumps and sputter ion pumps
to mitigate beam-gas interactions (ion trapping and beam loss)
Ready for In-situ Bakeout- no scrubbing eﬀect expected
Incoherent SR (ISR) power: 2.2 W (125 MeV, 100 mA)
Coherent SR (CSR) power:
77 W (125 MeV, 10 mA, σz = 0.3 mm)- no measures needed against the heat load of SR
adopt stainless steel (AISI 316L) as main material of beam tubes
High-power Beam Dump
- Max power load: initially 60 kW (6 MeV, 10 mA), ﬁnally 600 kW (6 MeV 100 mA)

Kapton Film Heater

ThicknessMax. TemperaturePower Density
Relative Permeability

250 µm
200 ℃
2.5 W/inch 21.004-1.006

cERL Vacuum System
Low-impedance Vacuum Components- need to be developed to accommodate high current (10~100 mA), low emittance(0.1~1 mm•mrad), and short pulse (0.1~3 ps) beams- adopt gap-less and step-less structures in ﬂanges, monitors, etc. to reduce
resistive wall wake ﬁelds, aiming at mitigation of BBU and chamber heating
Required Pressure- around SC cavities: 5×10-9 Pa by NEG-coated tubes (coated at ESRF)
to minimize gas condensation on cryo surface- in other regions:
1×10-7 Pa by lumped NEG pumps and sputter ion pumps
to mitigate beam-gas interactions (ion trapping and beam loss)
Ready for In-situ Bakeout- no scrubbing eﬀect expected
Incoherent SR (ISR) power: 2.2 W (125 MeV, 100 mA)
Coherent SR (CSR) power:
77 W (125 MeV, 10 mA, σz = 0.3 mm)- no measures needed against the heat load of SRadopt stainless steel (AISI 316L) as main material of beam tubes
High-power Beam Dump
- Max power load: initially 60 kW (6 MeV, 10 mA), ﬁnally 600 kW (6 MeV 100 mA)

460

Weight ~40 kg

OD:φ14ID:φ12ICF203FH

Absorber(GlidCop)

3 deg

φ12φ90φ50400350φ110

Support(SUS316)

30 degConditions
Electron Beam:- Energy: 6 MeV- Current: 10 mA- Power: 60 kW- Size: φ20 or φ30mm (uniform)

Main Beam Dump for cERL

Cooling Water:- Diff. Pressure: 0.5 MPa- Flow Rate: below 30 l/min(ΔT=28.7 ℃ @ 60 kW)- Flow Speed: below 10 m/s

2. Layout of the Vacuum Components

Schematic Layout of the cERL

Main Beam Dump

Main SC Cavity

Injector SC Cavity
Electron Gun

BPM (41)

CT (4)

Screen (25)DCCT (1)08b14b13

GV1025
4006

COL03
COL04

GV04

4107
b12b11b10

GV01

GV03

GV16

GV11

GV02

GV09

GV08

GV07

0405
b09

COL01
COL02

04b08

b07

b06

03
b05

b04

03

02

01

01

02

01

b01

b02

b33

b32

22

b03

23
11

12

1002

09

1306

07

08

2404

39

Beam Diagnostic Line

15

3803

GV05

140905

37

GV15

36
35

21

GV06

1634
17

33
19

18

b15

b16

b17

20

2221b18

b19

b20

23

24

b21

b22

25

b23

26

b24

b25

27

28b26

29b27

b28

30

b29

31b30

32b31

1020
11

12

13

14GV121516
GV13

Collimator (5)Circumference: 91.7 m

Gate Valve (16)171819GV14Movable Dump (1)Resonator for Laser
Compton Scattering

COL05

Merger Section
Injector
Superconducting
CavityNEG-coated Tube

Injecting 5-MeV Beam
Pumping Port
(NEG, SIP, CCG)

Beam Collimator

BPM

Beam
Collimator

BPM

ScreenMonitorCT

GV Bellows
Screen Monitor
Beam Diagnostic
Line

GV

Circulating
35-MeV Beam
Circulating
125-MeV Beam
(Upgrade)

CT GVMovable Dump1mInjector Commissioning(April ~ July 2013)
GateValve

GateValveBeam

NEG-coatedTube

ScreenMonitor
BeamCollimator
DCCTDiag.
Line75BPM

CT

Bellows
SIP

BPM

Gate
Valve
ScreenMonitor

NEG

CCG
RoughPump

SC
Cavity301

SIP 75

3. Summary of the Progress進捗状況のまとめ
・JAEA予算での周回部ダクト一式は3月22日納期に向けて製作中（一部、入射器コミッショニングに必要な機器は3月上旬に先行納品予定）
・NEGコーティングダクト、可動ダンプ、スクリーンモニタ2台も3月納品予定
・残りのスクリーンモニタ20台は来年度製作（担当: 高井）・主ビームダンプは今年度設計（熱構造解析）を行い、来年度に製作
・ポンプや真空計、制御機器類は概ね調達済み
・真空制御系は現在構築中（担当: 野上）
電子銃、超伝導空胴、診断ラインのゲートバルブも真空Grのインターロックに入れる方針