Packaging of Cryogenic Components

Transcription

1 Packaging of Cryogenic Components William J. Schneider Senior Mechanical Engineer Emeritus November

2 Packaging of Cryogenic Components Day one Introduction and Overview 2

3 What is important? Packaging of Cryogenic Components Results gradient MV/m, Field Tesla Heat Load low heat leak Multiple tests- retest of magnets or cavities Schedule demonstrate functionality Costs limited funds or stay within project costs Ease of production tradeoff of tooling versus people 3

4 Thermal Insulation In general cryogenic systems require a perfection of thermal insulation when compared to most other systems, but the choice usually comes down to a compromise of factors such as economy, convenience, weight, ruggedness and volume. 4

5 Superconducting Magnets Accelerator Magnets Detector Magnets Magnet Power Leads Magnet Lead Cans 5

6 Superconducting Magnets Operate at Helium Temperatures ~ 4 K Generally Niobium Titanium Superconductor Magnetic Fields range from 2 to 10 Tesla Accelerator magnets require excellent reproducibility due to multiple beam passes Detector magnets generally are quite large Detector magnets generally iron 6

7 Superconducting Magnets Accelerator and detector magnets cooled with forced flow helium Detector magnets cooled with bath cooling and thermal siphons Magnet leads optimized for conduction cooling and lead flow Magnet leads designed to Wiedemann Franz Law 7

8 Accelerator Dipole / Quadrupole Magnets Dipole / Quadrupole Magnets located in the (RHIC) Relativistic Heavy Ion Collider at Brookhaven National Laboratory Upton New York 8

9 Superconducting Accelerating Dipole Magnet RHIC Dipole Magnet Cross Section showing post support, cold mass and interconnecting piping Brookhaven National Laboratory (BNL) Upton New York 9

10 Superconducting Accelerator Magnet Transition of dipole magnet to End Can on the RHIC Dipole Assembly At BNL Upton NY 10

11 Atlas Detector at CERN LHC 11

12 Superconducting Detector Magnet Go Detector magnet in Experimental Hall C at Jefferson National Accelerator Laboratory, Newport News Virginia 12

13 Superconducting Detector Magnet Receipt of the CLAS Cebaf Large Angle Spectrometer Located in Hall B at Jefferson National Accelerator Laboratory Newport News Virginia 13

14 Septum Magnet with details of cryo can Septum Magnet located in Hall A At Jefferson National Accelerator Laboratory Newport News, Virginia 14

15 Magnet Power/ Trim Leads 15

16 Magnet Lead Can 16

17 Superconducting RF Cavities Temperature/Frequency/ Heat Shields Drift Tube Cavities Elliptical Cavities Couplers Waveguides 17

18 Superconducting RF Cavities RF Frequency sets temperature requirements Cavity temperature 1.8 to 4.5 K Superfluid requires 40 to 70 K heat shield Drift tube cavities used at low velocity Low beta cavities are for heavy ions Elliptical cavities used at high velocity Waveguides and Couplers provide power to cavity 18

19 SC Elliptical Cavities 19

20 RIA Drift Tube/Spoke Cavities 20

21 SNS and CEBAF SRF Elliptical Cavity (805 & 1497 Mhz ) 21

22 Superconducting Radio Frequency Cryomodules Low Beta SC RF Modules located at the SNS Spalation Neutron Source located at Oak Ridge National Laboratory Oak Ridge Tennessee 22

23 Superconducting Radio Frequency Cryomodule Cross Section of Low Beta SC RF Module located at the SNS Accelerator in Oak Ridge Tennessee 23

24 Superconducting Radio Frequency Cryomodule Covering Thermal Shield with Multi Layer Insulation (MLI) at assembly 12 GeV Upgrade Cryomodule for Jefferson Lab Newport News Virginia 24

25 Superconducting Radio Frequency Cryomodule Space Frame supporting Cold Mass on tooling in assembly area 12 GeV Upgrade Cryomodule at Jefferson Lab Newport News VA 25

26 Superconducting Radio Frequency Cryomodule Nitronic support rods and instrumentation heat stationed with copper straps to the heat shield. Multi layer insulation (MLI) is doubly aluminized mylar with a polyester spacer. Jefferson Lab 26

27 Superconducting Radio Frequency Cryomodule 12 GeV Upgrade Cryomodule Assembly showing insertion of Cold Mass into the Vacuum Tank. Outer sheet is the magnetic shield. Jefferson Accelerator Laboratory Newport News Virginia 27

28 Transfer Lines Shielded lines generally for superfluid helium and for liquid helium lines Nitrogen or higher helium temperature lines generally not shielded Bayonets generally quite long for superfluid Require guard vacuum sub atmospheric lines TL can be concentric tubes with vacuum space between to reduce heat leak to the superfluid 28

29 SNS tunnel transfer lines 29

30 Shielded Transfer Lines Supply and Return Transfer lines with return valve located in the tunnel of the Spallation Neutron Source (SNS) Oak Ridge National Laboratory Oak Ridge Tennessee 30

31 Superconducting Magnet, Supply Can and Lines Q2 Quadrupole with Supply Can on the (HRS) High Resolution Spectrometer In Hall A at Jefferson National Laboratory Newport News Virginia 31

32 Summary Day One Superconducting Magnets Heat load Radiation hardness Maintenance Alignment Cooldown rate Safety Facilities Volume Cost Superconducting Cavities Heat load Microphonics Cooldown rate Particulates Maintenance Alignment Safety Facilities Cost 32