Presentation on theme: "Measures of solid hydrogen contamination problem in the liquid helium Hiroshi Ikeda a,*, Yutaka. Kondo a Research Facility Center for Science and Technology."— Presentation transcript:
Measures of solid hydrogen contamination problem in the liquid helium Hiroshi Ikeda a,*, Yutaka. Kondo a Research Facility Center for Science and Technology Cryogenics Division, University of Tsukuba, Tsukuba, Ibaraki , Japan 6th International Workshop on Cryogenics Operations on November 2014
Gasbag PV3415 CV3401 V3410 CV3430 CV3420 Flow Meter Cold Gas Line Impurer Helium Gas Atmospheric release PV3435 TI3475 TI3465 Heater PI340 1 PI344 5 HP LineLP Line Liqide Air CV3410
ΔP ＝ 0.15MPa Cool down Mode Purify Mode Regeneration Mode Buffer tank
Quantum Design MPMS PPMS Flow impedance blocked by solid hydrogen (equipment to control temperature while limiting the flow of helium by a filter and capillary)
‣ For gas purity measurement discharged from the internal purifier was installed simple helium purity monitor immediately after the flow meter. Gas bag purity is reduced to 95% by the regeneration gas, introduction into the internal purifier, differential pressure occurs.
Gas Bag CV3415 CV3401 V3410 CV343 0 CV342 0 Flow Meter Cold Gas Flow Impurer Helium Gas CV343 5 TI3475 TI3465 Heater PI340 1 PI3445 HP LineLP Line Liqid Air １０ ０％ Purity Monter CV3410 Atmospheric release
Pirany type SKD-20 New Method ！ Ulvac WP-01
The purity of the regeneration gas was reduced to 33% at maximum Initial setting valu ・ Purification operation state Cold end temperature TI3475 = 32.5 K Internal pressure PI3445 = 2.5 MPa ・ Regeneration during operation Exit flow meter flow rate = 120 L/min Regeneration completion temperature TI3465 = 140 K Heater control temperature TI3475 = 95 K Warming heater output R3470 = 18 ％
Internal purifier Cold end temperature Internal purifier Exit flow rate TCF50 L280 ２７．５ K ３２．５ K ２００ L/min １２０ L/min High temperature! Low flow rate!
Gas Bag CV3415 CV3401 V3410 CV343 0 CV342 0 Flow Meter Cold Gas Flow Impurer Helium Gas CV343 5 TI3475 TI3465 Heater PI340 1 PI3445 HP LineLP Line Liqid Air １０ ０％ Purity Monter CV3410 Atmospheric release 120L/min ⇒ 190L/min Down fromD 32.5K
LHe GHe LN2 Gas Bag InPur GHe Adosorb er 3 point ! 80K 20K
LHe GHe LN2 Gas Bag Adsober Only One 20K InPur GHe
LHe GHe LN2 Gas Bag Adosober Revival ! 20K InPur GHe
Regeneration gas purity was improved from 33% to 99% by the setting change of internal purifier. Purification operation has stabilized generation of the differential pressure is reduced. By monitoring established the purity helium simple monitor, it can insight into the operating state of the internal purifier at a low cost. As the cause of differential pressure and decreased purity of the regeneration gas occurred, in addition to the incorrect setting, it is considered as the cause did not have the adsorber inside purifier.