Cryogenic Experts Meeting (19 ~ ) Helium distribution system for Super-FRS dipoles and multiplets MT/FAIR – Cryogenics and Magnets Y. Xiang, M. Kauschke, C. Schroeder, H. Leibrock

Cooling scheme for individual dipoles and multiplets of Super-FRS which is based on proven technology; Helium distribution system layout (flow schemes for individual valve boxes, heat loads and cryogenic facilities) Discussion of different alternatives for Super-FRS sc magnets cooling; Discussion of naming convention for flow scheme design Conclusions Outline Cryogenic Experts Meeting (19 ~ )

Courtesy of Martin Winkler Preliminary layout of helium distribution system for Super-FRS SC magnets

One example: the A1900 fragment separator at NSCL MSU 4 superconducting dipoles and 8 superconducting quadrupole triplets

Another example: quadrupole triplets in BigRIPS tunnel at RIKEN the first 5 bath-cooled superconducting quadrupole triplets share the same helium distribution system

Flow schemes of feedboxes for individual Super-FRS dipoles and multiplets single dipole single multiplet

Flow schemes of the Subcooler-box and the T-Branch box for Low and High Energy Branches

Flow schemes of one endbox and the T-branch box for main separator and ring branch

Helium distribution facilities for Super-FRS SC magnets TABLE 1. Helium Distribution Facilities for the Super-FRS Main ComponentsNumber / Length [m] feedboxes for individual sc magnets53 (28 dipoles + 25 multiplets) endboxes for cryogenic transfer line branches4 subcooler box and T-branch boxes1 + 2 = 3 cryogenic transfer lines (feedbox length included ) [m]~ 500 jumpers for connection to magnets53 warm helium/quench gas return piping [m]~ 500 instrumentation setups and warm gas control panes for feedboxes, endboxes, subcooler box and T-branch boxes = 60

Heat loads of the helium distribution facilities and SC magnets TABLE 2. Cryogenic heat load of Super-FRS Components /Temperature4 [K]50-80 [K] 53 Feedboxes + 4 End-boxes~ 280 (5 x x 4)~ 1700 Cryogenic transfer lines~ 150 (0.3 x 500)~ subcooler box and 2 T-branch boxes~ 50 (18 x x 2)~ 100 Dipoles + Multiplets~ 155~ 3010 current leads (5.8 g/s)~ 115 SUM [W]~ 750~ 5600

: helium distribution with reduced number (22) of feedboxes (MiniTAC Cryogenics, 30 ~ ) Discussion of different alternatives : helium distribution with reduced number (22) of feedboxes (MiniTAC Cryogenics, 30 ~ ) Comments and suggestions from experts of Mini-TAC Cryogenics Feed-boxes Minimize the number of feed box numbers and types.( e.g. serial magnet supply possible ?) Reconsider, if serial supply of sc magnets is possible! Serial supply could reduce the complexity (and costs) of the systems!

: Discussion of different alternatives : series cooling with supercritical helium and the recooling (MiniTAC Cryogenics, 30 ~ , MiniTAC SC Magnets, 15 ~ ) Features : Using supercritical helium forced flow cooling instead of liquid helium bath cooling; Using two-phase helium return flow to re-cool the forward supercritical helium; refrigerator compressor Quench/ cool down line coil feedbox 40 K forward 80 K Return Quench / cooldown SCHe 4.5 K forward 2-phase He recooling return Vapor LHe 300 K warm gas

: Series cooling with supercritical helium and the recooling (MiniTac Cryogenics, 30 ~ , MiniTAC SC Magnets) Discussion of different alternatives : Series cooling with supercritical helium and the recooling (MiniTac Cryogenics, 30 ~ , MiniTAC SC Magnets, 15 ~ ) endbox Feedbox T-junktion Our conclusion: series Comparing to the traditional cooling principle, supercritical helium series cooling scheme is a favorite solution from cost saving point of view, especially for the Super-FRS. The experts of MiniTAC SC Magnets 2005 were not convinced by this cooling principle due to the reason of no similar application found for such kind of magnets.

: Discussion of different alternatives : Series bath cooling for individual sc magnets of Super-FRS (MiniTAC SC Magnets, 24 ~ 25, May 2007) Feedbox Endbox Helium transfer line including T-connection boxes

TABLE 1. Helium Distribution Facilities for the Super-FRS Main ComponentsNumber / Length [m] Feedboxes/End-boxes8 Cryogenic transfer lines [m]500 Cryogenic T-connection box (each with one control valve) 53 Warm/quench gas piping including control panel [m] 500 Instrumentation setups for measurement and control 8 Comments and suggestions from experts of Mini-TAC SC Magnets 2007 Drop options requiring significant R&D (e.g. 2-phase counter- flow transfer line); Given the time-scale and available resources, it would be preferable to stay with proven technology (e.g. as used at MSU and RIKEN). : Discussion of different alternatives : Series bath cooling for individual sc magnets of Super-FRS (MiniTAC SC Magnets, 24 ~ 25, May 2007)

Comparison of different cooling principles for Super-FRS SC magnets Table 1: Advantages and disadvantages of different cooling methods for Super-FRS cryogenics Supercritical helium coolingIndividual liquid helium bath cooling Series bath cooling Cooling method feasibilityNo similar application for such kind of magnets  Proven technology for similar magnets Significant R&D is required for two- phase liquid helium distribution (experts of MiniTAC 2007)  Investment costs Less expensive Many valves are required => most expensive  Less expensive Cool down / warm up / downtime The system needs a longer downtime if one magnet is damaged.  More independent The system needs a longer downtime if one magnet is damaged.  Cryostat design requirementsHigher design pressure. special design is required  Low design pressure (standard design) Quench protectionSystematic protection for cryogenic facilities needed.  More individual Systematic protection for cryogenic facilities needed.  Control system Smaller and less expensive Complex and expensive  Smaller and less expensive. The long time constant must be considered Procurement and installation of cryogenic lines Highly dependent on the in situ welding and leak test quality control  Less sensitive to the overall system Highly dependent on the in situ welding and leak test quality control  Maintenance and reliabilityLess valves, less instrumentation setups Many valves, more instrumentation setups  Less valves, less instrumentation setups TestsExtra costs for test facility requirement emerge  Test could be very simple as a Dewar filling Connections must be welded for testing (no problem)

Discussion of Naming Convention for flow scheme design : Naming Convention of cryogenic instrumentation for LHC

Discussion of Naming Convention for flow scheme design : Naming Convention of cryogenic instrumentation for HERA Summary The Naming Convention of DESY was good and simple for the flow scheme design of the large scale cryogenic system of the HERA size which is of more or less the same complex as the FAIR cryogenic system. The Naming Convention of CERN fulfills the requirement of a highly complex and super-large size system as the LHC cryogenics. It facilitates the gathering, store, searching for and retrieve the information in Engineering Data Management System (EDMS) during the production, transport, installation, commissioning, operation, maintenance and re-cycling or dismantling of a part. So it is wise to keep such features when people makes the Naming Convention for FAIR cryogenics.

Preliminary layout which is based on proven technology has been done for the helium distribution system; Flow schemes for individual valve boxes, heat loads and cryogenic facilities of the helium distribution system has been presented; Different alternatives for Super-FRS sc magnets cooling have been discussed; Naming conventions for LHC and HERA cryogenic flow scheme design have been introduced. Conclusions Cryogenic Experts Meeting (19 ~ )