000057779 001__ 57779
000057779 005__ 20200221144319.0
000057779 0247_ $$2doi$$a10.1103/PhysRevApplied.6.024017
000057779 0248_ $$2sideral$$a97028
000057779 037__ $$aART-2016-97028
000057779 041__ $$aeng
000057779 100__ $$0(orcid)0000-0002-5022-5094$$aGabal, M.
000057779 245__ $$aHydrogen-Free Liquid-Helium Recovery Plants: The Solution for Low-Temperature Flow Impedance Blocking
000057779 260__ $$c2016
000057779 5060_ $$aAccess copy available to the general public$$fUnrestricted
000057779 5203_ $$aThe blocking of fine-capillary tubes used as flow impedances in He4 evaporation cryostats to achieve temperatures below 4.2 K is generally attributed to nitrogen or air impurities entering these tubes from the main bath. The failure of even the most rigorous low-temperature laboratory best practices aimed at eliminating the problem by maintaining the cleanliness of the helium bath and preventing impurities from entering the capillary tubes suggests that a different cause is responsible for the inexplicable reduction of impedance flow. Many low-temperature research laboratories around the world have suffered this nuisance at a considerable financial cost due to the fact that the affected systems have to be warmed to room temperature in order to recover their normal low-temperature operation performance. Here, we propose an underlying physical mechanism responsible for the blockages based upon the freezing of molecular H2 traces present in the liquid-helium bath. Solid H2 accumulates at the impedance low-pressure side, and, after some time, it produces a total impedance blockage. The presence of H2 traces is unavoidable due its occurrence in the natural gas wells where helium is harvested, forcing gas suppliers to specify a lower bound for impurity levels at about 100 ppb even in high-grade helium. In this paper, we present a simple apparatus to detect hydrogen traces present in liquid helium and easily check the quality of the liquid. Finally, we propose a solution to eliminate the hydrogen impurities in small- and large-scale helium recovery plants. The solution has been implemented in several laboratories that previously experienced a chronic occurrence of blocking, eliminating similar occurrences for more than one year.
000057779 536__ $$9info:eu-repo/grantAgreement/ES/MINECO/IPT-2012-0442-420000$$9info:eu-repo/grantAgreement/ES/MINECO/MAT2015-64083-R
000057779 540__ $$9info:eu-repo/semantics/openAccess$$aby$$uhttp://creativecommons.org/licenses/by/3.0/es/
000057779 590__ $$a4.808$$b2016
000057779 591__ $$aPHYSICS, APPLIED$$b21 / 147 = 0.143$$c2016$$dQ1$$eT1
000057779 592__ $$a2.448$$b2016
000057779 593__ $$aPhysics and Astronomy (miscellaneous)$$c2016$$dQ1
000057779 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/publishedVersion
000057779 700__ $$0(orcid)0000-0002-5999-341X$$aArauzo, A.$$uUniversidad de Zaragoza
000057779 700__ $$0(orcid)0000-0001-7289-5649$$aCamón, A.$$uUniversidad de Zaragoza
000057779 700__ $$aCastrillo, M.
000057779 700__ $$aGuerrero, E.
000057779 700__ $$aLozano, M.P.
000057779 700__ $$0(orcid)0000-0001-9897-6527$$aPina, M.P.$$uUniversidad de Zaragoza
000057779 700__ $$0(orcid)0000-0002-7742-9329$$aSesé, J.$$uUniversidad de Zaragoza
000057779 700__ $$aSpagna, S.
000057779 700__ $$aDiederichs, J.
000057779 700__ $$aRayner, G.
000057779 700__ $$aSloan, J.
000057779 700__ $$aGalli, F.
000057779 700__ $$aVan, Der Geest
000057779 700__ $$aHaberstroh, C.
000057779 700__ $$aDittmar, N.
000057779 700__ $$aOca, A.
000057779 700__ $$aGrau, F.
000057779 700__ $$aFernandes, A.
000057779 700__ $$0(orcid)0000-0002-5710-5562$$aRillo, C.$$uUniversidad de Zaragoza
000057779 7102_ $$15005$$2555$$aUniversidad de Zaragoza$$bDpto. Ing.Quím.Tecnol.Med.Amb.$$cÁrea Ingeniería Química
000057779 7102_ $$10$$2X$$aUniversidad de Zaragoza$$bServ.Gral. Apoyo Investigación$$cServicios. Div.Caract.Físi.Quí
000057779 7102_ $$12003$$2395$$aUniversidad de Zaragoza$$bDpto. Física Materia Condensa.$$cÁrea Física Materia Condensada
000057779 773__ $$g6, 2 (2016), 024017 [11 pp]$$pPhys. rev. appl.$$tPhysical review applied$$x2331-7019
000057779 8564_ $$s2558119$$uhttps://zaguan.unizar.es/record/57779/files/texto_completo.pdf$$yVersión publicada
000057779 8564_ $$s110771$$uhttps://zaguan.unizar.es/record/57779/files/texto_completo.jpg?subformat=icon$$xicon$$yVersión publicada
000057779 909CO $$ooai:zaguan.unizar.es:57779$$particulos$$pdriver
000057779 951__ $$a2020-02-21-13:40:31
000057779 980__ $$aARTICLE