제 2 회 국제선형충돌가속기 (ilc) workshop
DESCRIPTION
제 2 회 국제선형충돌가속기 (ILC) Workshop. 손 영욱 , 고 인수 , 남궁 원. 포항가속기연구소 , 포항공과대학교. 초전도 RF Cavity 의 기술 및 ILC 건설에 한국의 참여방안 , PAL 의 관련 연구소개. 2004. 12. 28-29 포항가속기연구소. Working Group 3: Accelerator Technology. Contents. Activities of PAL in SC RF Technology - beam dynamics - PowerPoint PPT PresentationTRANSCRIPT
제 2 회 국제선형충돌가속기 (ILC) Workshop
초전도 RF Cavity 의 기술 및 ILC 건설에 한국의 참여방안 , PAL 의 관련 연구소개
포항가속기연구소 , 포항공과대학교
Working Group 3: Accelerator Technology
손 영욱 , 고 인수 , 남궁 원
2004. 12. 28-29 포항가속기연구소
Contents
Activities of PAL in SC RF Technology - beam dynamics - cavity design - cryostat design
Technical Topics for SC RF Cavity Module
Proposal to Contribute ILC in Part of Cold
Technology
1/22
Activities of PAL in SC RF
초전도 3rd Harmonic RF cavity 의 feasibility study - Beam dynamics 측면에서 필요성 연구
o Beam emittance 의 개선으로 인한 빔수명단축을 개선 o Landau damping 에 의한 빔안정화 개선
초전도 3rd Harmonic RF cavity 의 Prototype 설계 - Cavity shape 선정 및 field 해석
- Prototype 공학설계
초전도 Cavity 제작공정 연구 - 제작공정에 대한 외국사례연구
- 국내 업체의 제작능력 조사
2/22
초전도 RF cavity 시험용 초저온 용기 설계
선진 연구 Group 의 자문 - 일본 KEK 시설견학 (K,Saito Lab.) 및 자문 - 스위스 SLS 시설견학 및 자문 - 독일 BESSY SC cavity 설계자 자문 - 이탈리아 ELETTRA 설계자 자문
Activities of PAL in SC RF
3/22
Feasibility Study of SC 3H Cavity for PLS in Beam dynamics
Fig. Lifetimes(□) and bunch lengths(●) with 3rd harmonic voltage
Fig. Potential well and longitudinal bunch distribution of PLS
4/22
Frequency 1500 MHz Cavity type Elliptical Diameter 19.2 cm Bore diameter 9.0 cm
PARAMETERS VALUE Material NiobiumCritical magnetic field 190 mTCritical temperature 9.2 KResistivity 1.724x10-9 mResidual resistance 1.077x10-6 Operating temperature 4.5 K
Table. Material Properties
Fig. Cavity Geometry
Preliminary Design of SC 3HC for PLS
5/22
Preliminary Design of SC 3HC for PLS
PARAMETERS VALUEAveraged accelerating field 4.20 MV/mFrequency 1499.99 MHzStored energy 0.1012 JoulesPower dissipation 15.88 W/cavityQuality factor 0.2403E+09 Shunt impedance 243671.03 MOhm/mRs*Q 258.95 Z*T*T 41505.11 MOhm/mGeometry factor(r/Q) 34.54 Ohm Ratio of peak fields Bmax/Emax 3.32 mT/(MV/m)Peak-to-average ratio Emax/E0 2.84
Table. RF characteristics
Fig. Accelerating field6/22
Conceptual Design of Cryomodule
Fig. Conceptual scheme of cryomodule for SC cavity
Port for Instruments Super-insulation30 layersSuper-insulation50 layers
LN2 Tube
Port for Vacuum PumpPort for RF Instruments
GHe Tube
LHe Tank(Titanium)
Thermal Shield (30K)
Thermal Shield (77K)
External Vacuum Tank(sus316) SC RF Cavity
(Niobium)Beam Tube(Niobium)
Beam Tube(Titanium) Beam Tube
(SUS 316)
Port for Cryogenic Devices
1200
600
7/22
Conceptual Design of Cryomodule
HEAT SOURCES VALUE (W)
Dissipations in cavity 32
Conduction via warm flange of cryomodule 11
Conduction via feed-through of instruments 8
HOM couplers (or absorber) ?
Cryogenic losses in cryogenic supply system 30
Total 81+
Table. Heat Loads of Cryogenic cooling system
()Total heat load depends on the scheme of HOM power removal and the piping distance between SC cavity and cold box of cryogenic system.
The refrigerator, of which capacity is more than 120 Watt, is required with consideration of capacity margin
8/22
Prototype 3rd harmonic cavity - Nb cavity with 2 volumes
- Test cryostat with multi-
purpose
- Cold test of SC cavity
- Design study
Cryostat for Vertical Test
TEST PORT
LHe TUBE
LN2 TUBE
GHe TUBE
GN2 TUBE
He LEVEL
N2 LEVEL
INSULATION PLUG
THERMALSHIELD (77K)
SUPERINSULATION
INSULATINGVACUUMVESSEL
TEST CRYOSTAT
2030
505
9/22
ParametersValue
s
Helium vessel neck diameter (mm) 505
Liquid helium volume (liter) 170
Liquid nitrogen volume (liter) 190
Working environment temperature (K) helium vessel nitrogen vessel
4.277.3
Liquid He consumption rate via cryostat (liter/hr)
0.7
Liquid He consumption rate via current leads (liter/hr)
2.4
Liquid nitrogen consumption rate (liter/hour) 0.7
Design pressure (Mpa) 0.25
Operation pressure helium vessel (Mpa) nitrogen vessel (Mpa) thermal insulation space (pa)
0.10.1
<10-6
Cryostat height (mm) 2200
Cryostat diameter (mm) 800
Total weight (Kg) ~300
Design of Test Cryostat
10/22
Critical magnetic field
Penetration depth, coherence length, G-L parameter, RF
critical magnetic field
Thermal conductivity
RRR measurement
Surface resistance in AC application
1. Superconductivity of Niobium
Technical Topics for SC RF Cavity Module
11/22
Cavity shape
Characteristic parameters of RF cavity
Analysis of electromagnetic fields
Engineering design
Planning fabrication and tests & measurements
2. Design of SC RF Cavity
Proposed 3rd Harmonic cavity for PLS F = 1499.994 MHz
E:\WORK\ACCELERATOR\THIRD HARMONIC CAVITY\FS-040319\TRIAL-1\MODE1500.AF 3-21-2004 21:41:54
0
2
4
6
8
10
12
14
0
2
4
6
8
10
12
14
0 2 4 6 8 10 12 14 16 18 20
Technical Topics for SC RF Cavity Module
12/22
Forming (deep drawing, spinning, hydroforming)
Coated cavity with Nb film
Trimming
Correcting machining error
Beam tube fabrication
Electron Beam Welding (EBW)
Bonding technology
3. Fabrication of SC RF Niobium Cavity
Technical Topics for SC RF Cavity Module
13/22
Mechanical grinding
☞ Centrifugal barrel polishing (CBP)
• Chemical polishing (CP)
• Electropolishing (EP)
• Heat treatment
• High pressure rinsing with ultra-pure water (HPR)
Ultrasonic rinsing
• Assembly in clean room
4. Cleaning & Conditioning
Technical Topics for SC RF Cavity Module
14/22
Theory of RF measurement of SC cavities
RF measurement system for vertical test;
electronic devices, monitoring sys., controller, etc
Cryogenics for cooling
RF accessories;
pickup/input coupler, RF generator, vacuum devices,
etc
5. Test & Measurements in Vertical Cryostat
Technical Topics for SC RF Cavity Module
15/22
Cavity disassembly after vertical test;
- preventing large degradation from exposure to air
- baking to recover performance
- removing indium sealing
Assembly in horizontal cryostat
6. Final Cavity Assembly Method with Cleanness
Technical Topics for SC RF Cavity Module
16/22
Technical Topics for SC RF Cavity Module
Design of horizontal cryostat for SC cavity modules
- horizontal test cryostat
- real cryostats for installation
Fabrication of horizontal cryostat
Test of cryostat performance
Assembly cryomodules with SC cavity
Design of cryo-plant
7. Cryogenics
17/22
Advanced Technical Issues(Challenges)
High gradient SC cavity, Eacc > 45 MV/m
- High pure niobium material, RRR~250 - Electropolishing (EP) - High Pressure Water Rinsing (HPR) - Baking (70~140oC)
Degradation-free final cavity assembly - Opening vacuum with argon gas - Simple aluminum vacuum sealing
Cost-effective cavity production method - Nb/Cu clad seamless cavity - Simplified surface treatment
18/22
Proposal to contribute ILC in part of SC RF Cavity
1. Establishment of technology for high gradient accelerating field,
Eacc 35 MV/m
- 일본 KEK, 미국 FNAL 등에서 기술개발 주도
- 한국의 PAL, … 등에서 공동참여 및 인력 training
2. Preliminary development of prototype cavity modules
- 설계 , 제작 , 시험 등 KEK, FNAL 등에서 개발 주도
- 한국의 PAL, … 등에서 인력지원 및 training
Work Process: Superconducting RF cavity
19/22
Proposal to contribute ILC in part of SC RF Cavity
3. Calculation & design of production cavities
- KEK, FNAL 등에서 개발 주도
- 한국의 PAL, … 등과 설계참여 및 training
4. Fabrication, cleaning & conditioning
- 국내 제작을 위한 시설확보 (PAL, …, 참여기업 )
- 제작후 processing 을 위한 시설확보 (PAL, 참여기업 )
- 국내 지분율에 해당하는 cavity 제작 (PAL, …, 참여기업 )
: 9-cell cavity 약 2,000 set
Work Process: Superconducting RF cavity
20/22
Proposal to contribute ILC in part of SC RF Cavity
5. Vertical test of 9-cell cavity
- Vertical test 를 위한 시설확보 (PAL, …)
- 9-cell cavity 에 대한 상온 및 저온상태에서 시험
(PAL, …)
Work Process: Superconducting RF cavity
21/22
Proposal to contribute ILC in part of cold technology
1. Assembly of cryomodule with 9-cell cavities - 시험용 horizontal cryostat 설계 , 제작 (KBSI, 참여기업 ) - Test facility 구축 (KBSI, 참여기업 ) - 양산용 cryostat 설계 , 제작 (KBSI, 참여기업 ) - 9-cell cavity 12 set 로 구성된 cryomodule 조립
2. Test & measurements with horizontal cryomodule - Test & measurements (KBSI) - Data analysis (KBSI, PAL)
Work Process: Cryogenics, Test & Measurement in Cryomodule
22/22
감사합니다 .