Gas dispensing control systems that use a gas expansion chamber with a plunger in fluid communication with both a vacuum pump and a nitrogen supply with a controller that calculates and dispenses standard volumes of gas based, at least in part, on local environmental conditions. The dispensed gas can be hyperpolarized .sup.129Xe for MRI imaging.

A cryostat arrangement (1), with a vacuum container (2) and an object (4) to be cooled, is provided, wherein the object (4) to be cooled is arranged inside the vacuum container (2) comprising a neck tube (8) leading to the object (4) to be cooled. A closed cavity (9) is formed around the cooling arm (10) of a cold head (11), wherein the cavity (9) in normal operation is filled at least partly with a first cryogenic fluid (34), and wherein a first thermal coupling component (15) is provided for the thermal coupling of the first cryogenic fluid (34) in the cavity (9) to the object (4) to be cooled. The cryostat arrangement (1) further comprises a pump device (14), to which the cavity (9) is connected, and with which the cavity (9) is configured to be evacuated upon failure of the cooling function of the cold head (11). Various cryostat configurations are provided.

Systems and methods are disclosed for containing parahydrogen. In some of the systems and methods, a gas cylinder is configured to contain hydrogen gas therein. The hydrogen gas may include parahydrogen gas at a first concentration of at least 45% and a pressure of at most 40 bar. The parahydrogen gas may have a decay time constant of at least 30 days. The parahydrogen gas may be for use in a PHIP, PHIP-SAH, SABRE, or PHIPNOESYS NMR or MRI experiment. In some of the systems and methods, a cryogenic chamber is configured to contain liquid hydrogen therein. The liquid hydrogen may include liquid parahydrogen at a concentration of at least 50 mole percent. The liquid hydrogen may be boiled to generate hydrogen gas containing at least 50 mole percent parahydrogen gas. The parahydrogen gas may be for use in a PHIP, PHIP-SAH, SABRE, or PHIPNOESYS NMR or MRI experiment.