Production Status ofVacuum Components
Y. Suetsugu
KEKB Vacuum GroupOutline
Production status
Beam pipes for arc section
 Bellows chambers, Gate valves Pumps Other componentsDesign status

2012/2/21

Movable mask (collimator)
Local correction region

Summary
KEKB Review 20121

OutlineProduction of vacuum components have started in fullswing this fiscal year.
Beam pipes
LER: Arc, Wiggler section, Straight section, etc.
 HER: Wiggler section, Straight section, Symmetry points, etc.
Components
Bellows chambers
 Gate valves Getter pumps
 Supports for beam pipes, ion pumps
 Gaskets, bolts, cooling pipes, etc.
Purchase of instruments for upgrading control system,
monitor system and pump system has also started.
 Designs and R&Ds for Movable mask and for theremaining sections (Local correction section, etc.) arein progress.
 Construction of facilities for Tin coating, pre-baking Talk by Shibata
2012/2/21

KEKB Review 20122

Production status: Beam pipe

LER wiggler section: already delivered last year
Nikko and Oho
 Copper beam pipes with antechambers
Type-S： 50, 183.5 m
 Type-Q: 27, 39.7m
Type-S has two clearing electrodes
Type-Q

Type-SElectrode

BPM Block
ＮＥＧ pump

2012/2/21

KEKB Review 20123

Production status: Beam pipeBeam pipes for arc sections: this yearAluminum-alloy beam pipes with antechambers
Formed with a extrusion method (A6063)
 Aluminum-alloy flange (A2219)
Type-S: 29 types, 271, 754.3 m
 Type-Q: 19 types, 310, 621.6 m
 Type-B: 5 types, 106, 485.0 m(1861 m)With groove structures
BPM block

ＳＲ Mask

Aluminum-alloy beam pipeType-Q

Groove structure

Type-B
Type-S

2012/2/21

KEKB Review 20124

Production status: Beam pipe
Mass production is in progress in BINP (Novosibirsk).

2012/2/21

KEKB Review 20125

Production status: Beam pipe
The first containers have been delivered last week.

2012/2/21

KEKB Review 20126

Production status: Beam pipe

HER wiggler section: this year
The same structure to LER, but no electrodes Copper beam pipes with antechambers
Type-S：14, 49.4 m
 Type-Q: 8, 14.1m
Type-Q

Chicane, Downstream of LER, HER wigglers: this yearHigh SR power  Special cooling water paths
 Race-track cross section at downstream (HER) LER: 32 types, 58, 144.2m
 HER: 12 types, 12, 32.3m
2012/2/21

KEKB Review 20127

Production status: Beam pipe

HER symmetry section: this year
New magnets are installed.
 Race track type(104x50)
Symmetry point Copper 4 types, 24,35.3 m


LER Oho RF cavity section: this year
New RF section
 Same cross section to KEKB RF section (Φ150)
 CopperBeam pipes for RF section (KEKB)
 1 type, 4,11.7m

2012/2/21

KEKB Review 20128

Production status: Pump


ScreenGetter pump: this year

Main: Three layers of NEG strips ST707 3D

Installed into an antechamber



Activated by micro-heaters (sheath heaters)
Screens between pump and beam

NEG strips (3m x 2400), Heaters (1070),transformer (1105), Feed-though (950)
will be delivered this year.

3 layer strips

Installation of NEG
NEG strip

Screen(Φ4mm、6mm pitch)Feed-throughFeed-through2012/2/21

KEKB Review 20129

Production status: Bellows chamberWiggler and straight sections: this yearWith Comb-type RF shield Copper: Wiggler, Straight, HER arc:16 (last year)+205
 Copper: HER Arc: 38
 Aluminum alloy: LER Arc : 690
Copper bellows chamber

Aluminum alloy bellows chamber

Inside2012/2/21

InsideKEKB Review 201210

Production status: Bellows chamber

Mass production is in progress at several Japanesecompanies.

2012/2/21

KEKB Review 201211

Production status: Gate valves, etc.
Gate valves: this year
With comb-type RF shield Stainless steel (copper shield)

2-types, 24

RF shield for GV

Metal gaskets: this year
For special connection flange Copper: 1000, Aluminum-alloy: 1500


CopperAluminum alloy
2012/2/21

KEKB Review 201212

Production status: Supports
For BPM

Supports: this year

For gate valve

For Ion pumps at arc, 234
 For gate valves, 16 For Type-B beam pipes, 246


Fixed to bending magnets

For Type-A

For Type-S beam pipes, 396
 For Type-Q: Reuse

For Ion pump(Straight)

For Type-B

For Type-S
For ion pump

2012/2/21

KEKB Review 201213

Production status: Layout in tunnel
Layout of beam pipes in arc section
B magnet
Bellowschamber
Type-SBellowschamber

Type-B
Support for
Type-BBPM

Q magnet
SX magnet

Ion pump (Rough pump)Type-Q(STH, V)

Support for ionpump
Support for
Type-S

2012/2/21

KEKB Review 2012

Supportfor
Type-Q
Support for
Type-S
14

Design status: Movable mask
Movable mask (Collimator)
Indispensable for the reduction ofback ground Horizontal and Vertical masks
 Design: Based on the PEPII type Conceptual design has been
done this year.
Shield fingers[Horizontal]

Mask head

Cooling water

Basic specification
Length of head：~2 R.L.
 Both inside and outside of thering (Horizontal), top and bottom(Vertical)
 Accuracy of positioning：0.05mm
 Feedback of beam position

Tapered pipe

[Vertical]

Mask head
Cooling water
2012/2/21

KEKB Review 201215

Design status: Movable mask

RF properties: since last year


Loss factors：~1x1011 V/C @σz=6mm, d = 5 mm

TMC(Transverse Mode Coupling Instability)dHeadHead
Kick factor：~2x1014 V/C @σz=6mm, d = 5 mm
Beam15 V/C@ d = 1mm
 Large dependence on d：3x10
 Severe for small gap: Optimization of the locations are in progressconsidering the effect on the back ground (Nakayama-san)k ⊥ = 0.215 AZ 0 c

2012/2/21

KEKB Review 20121θ, A = (~ 1)2
σ zd 316

Design status: Movable maskMaterial of headTo be considered:
Radiation length Tolerability for beam
 Thermal conductivity
 Electrical conductivity
Candidate*
CopperCu
Chrom
Cr
CobaltCo
Hafnium
HfIridium
Ir
Molybdenum Mo
Niobium
Nb
Palladium
Pd
PlatinumPt
Rhenium
ReRhodium
Rh
Ruthenium Ru
TantalumTa
Titanium
Ti
Tungsten
W
Zirconium
ZrBerylium
BeGraphiteC Strength in high T
Machinability Availability
 Gas desorption
 Junction characteristic (HIP, Brazing)
Melting Specific SpecificThermal
Specific Radiation Linear
Atomic Atomic Density
point heatheat
conductivity resitance length
expansion
number waight [g/cm3][℃][J/g/K] [J/cm3/K] [W/m/K]
[nΩm]
[mm]
[1e-6/C]
2963.58.93 1083
0.386
3.44698
397
16.94
14.73
172452
7.19 1857
0.461
3.31459
91.3
132
21.21
6.5
27
58.9
8.9 1495
0.427
3.8003
96
63.4
15.63
12.5
72 178.5
13.28 2227
0.147
1.9521622.93225.20677 192.2
22.4 2443
0.13
2.912
146.9
51
2.93
6.8
42 95.94
10.2 2620
0.251
2.5602
137
57
9.84
5.1
41
92.9
8.57 2467
0.268
2.29676
54.1
160
11.86
7.2
46 106.4
12.16 1552
0.247
3.00352
75.2
108
7.74
11
78 195.1
21.45 1769
0.134
2.8743
73.4
105.8
3.04
9
75 186.2
21.03 3180
0.138
2.90214
47.6
187
3.18
6.6
45 102.9
12.44 1966
0.243
3.02292
148
47
7.62
8.5
44101
12.2 2250
0.234
2.8548
116.3
77
7.95
9.6
73 180.9
16.6 3015
0.142
2.3572
57.55
135
4.11
6.5
24 47.88
4.5 1667
0.528
2.376
21.6
540
31.21
8.9
64 183.9
19.3 3400
0.138
2.6634
174.3
54
4.58
4.5
40 91.22
6.5 1852
0.289
1.8785
22.6
440
16.07
5.9
4
9.02
1.84 1287
2.052
3.77568194
33
353.57126
122.25 <3370
0.7
1.575
100
500
190.97*Basically high melting point considering the irradiation of synchrotron radiation.
2012/2/21

KEKB Review 201217

Design status: Movable mask


Estimation of temperature rise by beam hitting
Using EGS4 Monte Carlo method (by Sanami-san): Cylindrical beam

Example for MO

∆Tfor 1x1012 e-/pulse

ρ =50μm ⇒ρ =500μm ⇒1x1012 e-/pulse  16 mA
For the effective bunch radiusof 50μm, Mo will melt for anythickness. May be OK for theradius of 500μm.
Temperature rises were
estimated for variousmaterials.

Z [R. L.]2012/2/21

KEKB Review 201218

Design status: Movable mask

Temperature for promising materials
Low temperature and high melting point: Be, C, Al, Ti, Cr, Mo, W Note: Any materials should melt if whole beams hit the head.



3.6 A  2.25x1014 e-/pulse; 225 times higher than the simulation

Temperature [C]1000001x1012 e-/pulse
Radius = 50 µm
R.L.=0.5

Max. Temperature

10000

1000

Fast beamabort system isessential!

Melting point100( Al ) Be C Co Cr Cu Hf Ir Mo Nb Pd Pt Re Rh Ru Ta Ti W Zr
2012/2/21

KEKB Review 201219

Design status: Movable maskMaterial of head: Comparison
Heating bybeam
hitting

Necessary
Length(2RL)

Thermal &Electricalconductivity

Availability
Machinability

Gas
DesorptionBe◎△(700mm)◎×△C◎△(380mm)

××○

Ti○○(62mm)

×○◎

Cr○○(42mm)△○△

Mo○○(20mm)○×○

W○○(10mm)◎△◎

Ta○○(8mm)△○◎

Tungsten (W) seems the most promising.
HIP (Hot Isostatic Pressing) test in undergoing this year
(Tungsten, Copper, Stainless steel) to check the junction
property.

2012/2/21

KEKB Review 201220

Design status: Movable mask

Design and production of a test model: next yearStudy measures against the damage of head
Replaceable head? Slide mechanism?
 Fast abort system will be essential.
Check mechanical accuracy, cooling property
 Design of HOM absorbers
2012/2/21

KEKB Review 201221

Design status: Remained sections
Beam pipes for Local correction section
Aperture will be fixed soon.
 Low pressure is required to reduce back ground:Combination of “photon stop and lumped pumps”+ “Distributed pumps”

Copper at upstream considering back ground?

φ80+ Antechambers

50x44 ellipse+ Antechambers

φ90+ Antechambers
The same to Arc
2012/2/21

KEKB Review 201222

Design status: Remained sections
Other special beam pipes
Cross at Fuji: 7 m [LER]: 11 m [HER]
Overpass

Special beam pipes
Type-Q for Skew-SX
 Beam injection, Beam dump
 X-ray profile monitor [LER and HER])Fuji cross

2012/2/21

Injection

KEKB Review 2012

Abort23

Installation


Rough schedule

2012/2/21

KEKB Review 201224

InstallationPreliminary vacuum tests


Copper beam pipe for wiggler section (with electrode)
Baking up to 120°C was possible.
-8 Base pressure ~ 3×10 Pa with
Lumped NEG + TMP

NEG strip assemblyST707 strips with sheath heaters

Aluminum beam pipe with NEG assembly
Baking at 150C and NEG activation
 Base pressure ~ 210-8 Pa withNEG assembly + TMP

2012/2/21

KEKB Review 201225

Summaries


Production of various vacuum components has started
Beam pipes and other components for arc section andwiggler sections are in the process of production and will
be delivered this year.
Movable mask, and the remained beam pipes andcomponents for the local correction section etc. are inthe design phase.
Almost on schedule, but some components are runningslow.

The production will start soon for some components.

Prebaking and TiN coating (for LER beam pipes) willstart soon. Installation in to the ring will start from themid of next fiscal year.
Preliminary vacuum tests has just started.

2012/2/21

KEKB Review 201226

Back up2012/2/21

KEKB Review 201227

Average pressure in arc


1m beam pipe (with TiN coating)
Thermal gas desorption rate (filled by 25℃ air)
– Qth = 7.77x10-9x5.4x10-1=4.2x10-9 Pa m3/s/m (After 60hourspumping)Average photon density (3.6 A):– LER: 5.3x1018 photons/s/mIf η = 1x10-6 [molecules/photon]– Qpsd= 2.2x10-8 Pa m3/s/m



For the effective pumping speed of 0.1 m3s-1m(After activation of NEG),
P = Q/S = 2.2x10-7 Pa

2012/2/21

KEKB Review 201228

Loss factors
Loss factors and kick factors for main components
2011/2/1 末次
Component

Resistive wall

Loss factor [V/C] Number of items
AlCu

Pumping port
Flange connection
Bellows
Gate valve
SR maskMovable mask
Taper
BPM
BxB FB BPM
FB kicker
IP chamber
GrooveGroove (RW x 0.14)*
Clearing ElectrodeCle Ele (RW-W)**
Cavity (ARES)
Total
Al

1.14E+09
8.22E+08
3.65E+02
1.45E+07
2.00E+09
3.00E+09
1.82E-03
1.00E+11
3.83E+08
1.63E+08
5.90E+08
5.01E+11
8.00E+08
1.00E+08
1.60E+08
2.00E+08
8.70E+08
4.35E+113000 [m]3000 [m]3000 [m]
2000
900
40
1000
8 ?
100
450
10
1
1550 [m]550 [m]160 [m]160 [m]18

Loss factor(total) [V/pC]
3.42
1.10E-06
0.03
1.80
0.12
1.82E-120.80
3.83E-02
0.07
5.90E-03
0.50
8.00E-04
5.50E-02
8.77E-02
3.20E-02
1.39E-01
7.83
14.9 +α

Kick factor(total) [V/pC/m]

35.00

~1000

2.50?
5.50
27.00
1.20

* RW 50%増し x 80/(90*π)** タングステン 40mm分
2012/2/21

KEKB Review 201229

Countermeasures against Electron Cloud

Summary of countermeasures

Sections

L [m]

L [ %]Countermeasure

MaterialTotal

3016

100

Drift space (arc)1629 m54

TiN coating + Solenoid

Al or Cu

Steering mag.

316 m

10

TiN coating + Solenoid

Al or Cu

Bending mag.

519 m

17

TiN coating + Grooved surface

Al or Cu

Wiggler mag.

154 m

5Clearing ElectrodeQ & SX mag.

254 m

9

TiN coating

Al or Cu

RF section

124 m

4

(TiN coating +) SolenoidCu

IR section

20 m

0.7

(TiN coating +) Solenoid

Al or Cu

NewCuElectron density less than 1.0×1011 e-/m3 is expected.

2012/2/21

KEKB Review 201230