FRESCA 2 cryostat design Maciej Grabowski CERN Geneva

FRESCA 2 cryostat design Maciej Grabowski CERN Geneva, 21. 03. 2018

FRESCA 2 Contents 1. 2. 3. 4. 5. Flow scheme of FRESCA 2 General information Review of internal cryostat modules Review of external cryostat modules Assembly process of FRESCA 2

FRESCA 2 Flow scheme

FRESCA 2 General view Sample holder Inner cryostat Outer cryostat Magnet Cryostat height ~4, 4 m with sample holder ~5, 15 m Outer diameter ~2 m

FRESCA 2 Cryostat equipment view Actuator system for lambda valve IC LN 2 bayonet Safety plates Rupture disks Sample holder Cryogenic transfer line connection ports Cryogenic valves OC LN 2 bayonet Current leads

FRESCA 2 Useful space for personel on FRESCA 2 space reserved for cryostat operators

FRESCA 2 Layout of process pipes in cryostat cryogenic ports

FRESCA 2 Inner cryostat – helium vessel instrumental vessel He II main helium vessel IC lambda plate

FRESCA 2 Inner cryostat – helium vessel Main helium vessel Sample holder IC lambda plate He II Instrumentation vessel Connection pipes

Advantages of the IC He vessel diameter reduction • Smaller He vessel - lower wall thickness = lower heat flux to He • Smaller He inventory = shorter cool down time from 4. 2 K to 1. 9 K • Lower heat flux to L-V heat exchanger – better thermodynamic performance • Lower heat flux to He in the He vessel through control valves

FRESCA 2 Inner cryostat – helium supply and return pipes Helium common supply line ON/OFF helium cryogenic supply valves Helium top supply line Helium bottom supply line

FRESCA 2 Inner cryostat – helium supply and return pipes Helium return line

FRESCA 2 Inner cryostat – instrumentation vessel Lambda valve Rupture disk Lambda plate Metal seal

FRESCA 2 Inner cryostat – instrumentation insert lambda valve actuator electrical feedthrough liquid level sensor holder electrical feedthrough port

FRESCA 2 Inner cryostat – L-L helium heat exchanger

FRESCA 2 Inner cryostat – L-L HX – instrumental system 36 HX segments Total heat transfer area ~0, 6 m 2 U-shaped heat exchanger segment

FRESCA 2 Inner cryostat – L-L HX – U-shaped assembly Metal sleeves Brazing connection Copper pipe Metal plate

FRESCA 2 Inner cryostat – L-L HX – instrumental system Helium guard system Rupture disk Instrumentation pipe Electrical feedthrough Liquid level sensor holder

FRESCA 2 Inner cryostat – L-V helium heat exchanger JT valve

FRESCA 2 Inner cryostat – L-G helium heat exchanger Vapour pumping line JT valve Outflow of helium from L-G HX to JT valve Inflow of helium to L-L HX L-G helium heat exchanger Outflow of helium from He vessel to L-G HX Outflow helium vapours from L-L HX to L-G HX

FRESCA 2 Inner cryostat – thermal shield Aluminium shield LN 2 SS cooling pipe

FRESCA 2 Inner cryostat – thermal shield Termalization of the cooling pipe with aluminium shield

FRESCA 2 Inner cryostat – thermal shield TS hanger Termalization of TS to IC He vessel

FRESCA 2 Inner cryostat – thermal shield Elements for fastening the cooling pipe to the shield Screws for connection of shield elements Venting hole

FRESCA 2 Inner cryostat – thermal shield Direction of the shueld removal

FRESCA 2 Inner cryostat – vacuum vessel Current leads Foam insulation Radiation buffers OC lambda valve actuator Rupture disk Vacuum vessel

FRESCA 2 Outer cryostat – helium vessel current leads He I OC lambda plate magnet He II helium vessel

FRESCA 2 Outer cryostat – helium vessel OC safety devices OC lambda plate OC lambda valve magnet Process pipes OC L-L heat exchanger

FRESCA 2 Outer cryostat – lambda plate and lambda valve Lambda valve lifting system Lambda plate Lambda valve Fastening screw Metal seal

FRESCA 2 Outer cryostat – fixing the magnet Fixing the magnet holders to the plate fixing the magnet holders to the magnet

FRESCA 2 Outer cryostat – L-L helium heat exchanger 24 HX segments Total heat transfer area ~1, 64 m 2 U-shaped heat exchanger segment

FRESCA 2 Inner cryostat – L-L HX – instrumental system Rupture disk Instrumental pipe Liquid level sensor holder

FRESCA 2 Outer cryostat – thermal shield LN 2 bayonet connection LN 2 cooling pipe Aluminium shield

FRESCA 2 Outer cryostat – thermal shield TS suspension Termalization TS to maim cold vessel

FRESCA 2 Inner cryostat – thermal shield Elements for fastening the cooling pipe to the shield Termalization of cooling pipe with aluminium shield

FRESCA 2 Inner cryostat – thermal shield

FRESCA 2 Inner cryostat – thermal shield Directions of the shield disassembly

FRESCA 2 – ASSEMBLY PROCESS OC cryostat assembly He vessel of the outer cryostat

FRESCA 2 – ASSEMBLY PROCESS OC cryostat assembly OC thermal shield

FRESCA 2 – ASSEMBLY PROCESS OC cryostat assembly OC Vacuum vessel

FRESCA 2 – ASSEMBLY PROCESS Magnet installation and positioning OC lambda plate with the magnet holders

FRESCA 2 – ASSEMBLY PROCESS Magnet installation and positioning System for positioning the magnet during its assembly

FRESCA 2 – ASSEMBLY PROCESS Magnet installation and positioning Magnet mounting under the plate. Elemet for blocking of the insert rotation.

FRESCA 2 – ASSEMBLY PROCESS Magnet installation and positioning Removing the system for positioning the magnet

FRESCA 2 – ASSEMBLY PROCESS Magnet installation and positioning Inserting the OC lambda plate with suspended magnet

FRESCA 2 – ASSEMBLY PROCESS OC cryostat assembly Inserting the IC vacuum vessel

FRESCA 2 – ASSEMBLY PROCESS IC cryostat assembly IC He vessel

FRESCA 2 – ASSEMBLY PROCESS IC cryostat assembly IC thermal shield

FRESCA 2 – ASSEMBLY PROCESS IC cryostat assembly Sample holder

FRESCA 2 – ASSEMBLY PROCESS Final assembly