A heat exchanger comprises a glass body having a first flat face and a second flat face on opposing ends, and defining a longitudinal axis therebetween. A plurality of holes in the glass body are elongated along the longitudinal axis by extending from said first flat face to said second flat face. The plurality of holes are configured to receive and direct a gas therethrough, to exchange heat between the gas and the glass body.

A method includes exposing a non-aqueous solution to ultraviolet illumination, where the non-aqueous solution includes one or more lanthanide elements and one or more photo-initiators. The method also includes producing lanthanide nanoparticles using the non-aqueous solution. The non-aqueous solution could be formed by mixing a first non-aqueous solution including the one or more lanthanide elements and a second non-aqueous solution including the one or more photo-initiators. The non-aqueous solution could include one or more metallic salts, where each metallic salt includes at least one lanthanide element. The one or more metallic salts could include erbium chloride, and the one or more photo-initiators could include benzophenone. The non-aqueous solution could include an organic solvent, such as an alcohol.

Provided is a group of rare-earth regenerator material particles having an average particle size of 0.01 to 3 mm, wherein the proportion of particles having a ratio of a long diameter to a short diameter of 2 or less is 90% or more by number, and the proportion of particles having a depressed portion having a length of 1/10 to of a circumferential length on a particle surface is 30% or more by number. By forming the depressed portion on the surface of the regenerator material particles, it is possible to increase permeability of an operating medium gas and a contact surface area with the operating medium gas.

A compact, low power cryo-cooler for cryogenic systems capable of cooling gas to at least as low as 2.5 K. The cryo-cooler has a room temperature compressor followed by filtration. Within the cryostat, four counterflow heat exchangers precool the incoming high-pressure gas using the outflowing low-pressure gas. The three warmest heat exchangers are successively heat sunk to three stages of a pulse tube to absorb residual heat from the slight ineffectiveness of the heat exchangers. The pulse tube cold head also absorbs loads from instrumentation leads and radiation loads. The pulse tube stages operate at around 80 K, 25 K, and 10 K. The entire systemcryo-cooler, drive and control electronics, and detector instrumentation, fits in a standard electronics rack mount enclosure, and requires around 300 W or less of power.

A pulse tube cryocooler includes: a pulse tube having a pulse tube high-temperature end and a pulse tube low-temperature end, and extending in an axial direction from the pulse tube high-temperature end to the pulse tube low-temperature end; a regenerator having a regenerator high-temperature end and a regenerator low-temperature end, and being disposed rowed alongside the pulse tube, with the regenerator high-temperature end being positioned displaced, in terms of the axial direction, from the pulse tube high-temperature end toward the cryocooler low-temperature side, and the regenerator low-temperature end being fluid-passage linked with the pulse tube low-temperature end; and a pressure-switching valve for connecting the regenerator high-temperature end to a high-pressure source and to a low-pressure source in alternation, and being disposed between the pulse tube high-temperature end and the regenerator high-temperature end in terms of the axial direction.

An apparatus includes a glass body having a first face and a second face on opposing ends and defining a longitudinal axis between the opposing ends. The glass body includes an exterior surface continuously extending from the first face to the second face. The glass body also includes an interior surface surrounding an aperture, the aperture extending longitudinally from the first face to the second face. The glass body further includes a plurality of holes surrounding the aperture, where the holes are disposed within the glass body and extend longitudinally from the first face to the second face. The holes are configured to receive and direct a gas through the holes to exchange heat between the gas and the glass body.

Heat regenerators and related methods enable heat transfer in an embedded structure of a heat regenerator. The heat regenerators enable a reduction of the pressure drop due to fluid flow through the heat regenerator and consequently an increase of power density. A heat regenerator includes a housing having a primary hot heat exchanger and a primary cold heat exchanger between elements for the oscillation of a primary fluid. The secondary fluid unidirectionally flows from the heat sink into the primary cold heat exchanger. The secondary fluid exits from the primary cold heat exchanger and unidirectionally flows towards the heat source. The secondary fluid S enters the primary hot heat exchanger and exits as the unidirectional flow of the secondary fluid S of the primary hot heat exchanger towards the heat sink. Between both primary heat exchangers, the porous regenerative material is positioned as part of the regenerator.

A regenerative refrigerator includes: a regenerator unit that precools a working gas; and an expander that cools the working gas by expanding the working gas precooled by the regenerator unit. The regenerator unit includes a zinc based regenerator member formed of zinc or an alloy containing zinc as a main component of the alloy. A first stage regenerator optionally includes a high temperature part including a first regenerator member and a low temperature part including a second regenerator member different from the first regenerator member. A second stage regenerator optionally includes a high temperature part including a second regenerator member and a low temperature part including a third regenerator member different from the second regenerator member. The second regenerator member optionally includes a zinc based regenerator member formed of zinc or an alloy containing zinc as a main component of the alloy.

In a cryogenic regenerator including a regenerator tube, a partitioning tube, whose tube wall is perforated by uniformly distributed through-holes, inside of which regenerator packing is provided, and having rib rings wrapped peripherally around its outer wall, is arranged coaxially inside the regenerator tube, with a buffer cavity between the regenerator-tube inner wall and the partitioning-tube outer wall. In a pulse-tube refrigerator including the regenerator and a gas reservoir, the regenerator, thanks to the designing of its reservoir and through-holes, draws in radial flows such that the form of heat exchange in the same regenerator cross-section goes from being simple thermal conduction to being heat exchange in which heat convection is coupled with thermal conduction, enhancing radial heat transfer and enabling rapid equilibration of temperature gradients along the regenerator periphery, and, by effectively keeping non-uniformity phenomena inside the regenerator under control, making improved refrigerator efficiency possible.

Provided is a group of rare-earth regenerator material particles having an average particle size of 0.01 to 3 mm, wherein the proportion of particles having a ratio of a long diameter to a short diameter of 2 or less is 90% or more by number, and the proportion of particles having a depressed portion having a length of 1/10 to of a circumferential length on a particle surface is 30% or more by number. By forming the depressed portion on the surface of the regenerator material particles, it is possible to increase permeability of an operating medium gas and a contact surface area with the operating medium gas.