Magnetocaloric Effect of Polycrystal GdLiF4 for Adiabatic Magnetic Refrigeration

Numazawa, Takenori; Kamiya, Kōji; Shirron, Peter; DiPirro, Mike; Matsumoto, Koichí

doi:10.1063/1.2355309

Cited by 29 publications

(24 citation statements)

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“…FIGURE 1: Zero--field entropies for common magnetocaloric materials used in low temperature ADRs. [16,17,18] Figure 1 shows the zero--field entropy curves for some of the most common magnetic refrigerants use in ADRs, and Table 1 summarizes their relevant parameters, including coefficients for b(T). The Neel temperature, at which the material enters an ordered magnetic state, shows a clear correlation with J and magnetic ion density.…”

Section: Magnetocaloric Effectmentioning

confidence: 99%

Applications of the magnetocaloric effect in single-stage, multi-stage and continuous adiabatic demagnetization refrigerators

Shirron

2014

Cryogenics

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Adiabatic demagnetization refrigerators (ADR), based on the magnetocaloric effect, are solid--state coolers that were the first to achieve cooling well into the sub--kelvin regime. Although supplanted by more powerful dilution refrigerators in the 1960s, ADRs have experienced a revival due to the needs of the space community for cooling astronomical instruments and detectors to temperatures below 100 mK. The earliest of these were single--stage refrigerators using superfluid helium as a heat sink. Their modest cooling power (<1 µW at 60 mK[1]) was sufficient for the small (6x6) detector arrays[2], but recent advances in arraying and multiplexing technologies[3] are generating a need for higher cooling power (5--10 µW), and lower temperature (<30 mK). Single--stage ADRs have both practical and fundamental limits to their operating range, as mass grows very rapidly as the operating range is expanded. This has led to the development of new architectures that introduce multi--staging as a way to improve operating range, efficiency and cooling power. Multi--staging also enables ADRs to be configured for continuous operation, which greatly improves cooling power per unit mass. This paper reviews the current field of adiabatic demagnetization refrigeration, beginning with a description of the magnetocaloric effect and its application in single--stage systems, and then describing the challenges and capabilities of multi--stage and continuous ADRs.

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Section: Magnetocaloric Effectmentioning

confidence: 99%

Applications of the magnetocaloric effect in single-stage, multi-stage and continuous adiabatic demagnetization refrigerators

Shirron

2014

Cryogenics

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“…The entropy change of GOS was less than that of GdLiF 4 , which is currently used in the high temperature stage of ADRs [8]. However, when we see figure 7 and 8, we could confirm that the entropy curve at 0 T was larger than that at 5 T, between 5 and 6 K. This is considered an inverse magnetocaloric effect [9] [10] [11].…”

Section: Resultsmentioning

confidence: 73%

Magneto Caloric Properties of Polycrystalline Gd₂O₂S for an Adiabatic Demagnetization Refrigerator

et al. 2017

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Abstract. Currently, many space missions that use cryogenic equipment are being planned. In particular, high resolution sensors, such as transition edge sensors, require very low operating temperatures, below 100 mK. Adiabatic demagnetization refrigerator (ADR) systems are a useful tool for producing ultra-low temperatures in space because these devices can operate independently of gravity. The magnetic material is one of the most important components with respect to effectiveness of the cooling power. Thus, we could increase the cooling power using a magnetic material that has a large entropy change over the operating temperature range. Polycrystalline Gd2O2S (GOS), which was developed by Numazawa et al, can be used as such as a magnetic regenerator material. Furthermore, GOS has a very large specific heat and a magnetic phase transition temperature of about 5.2 K. These features make GOS suitable for use in the high temperature stage of an ADR. In this study, we measured and evaluated the physical properties of GOS for applications to ADRs.

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“…For 50 mK operation, chrome potassium alum (CPA) provides better entropy capacity and lower temperature capability than the ferric ammonium alum used on Astro-E/E2 to reach 60 mK. For the warmer stages, research at GSFC over the last 10 years has identified a new material, gadolinium lithium fluoride (GLF) 8 that has 30% higher entropy capacity per volume than gadolinium gallium garnet (GGG) 9 , yet lower temperature capability (0.25 K versus ~0.8 K). This increases performance and opens up a much wider parameter space for optimizing the design, which is summarized in Table 2.…”

Section: Adr Designmentioning

confidence: 99%

Design of a 3-stage ADR for the soft x-ray spectrometer instrument on the ASTRO-H mission

Shirron

Kimball

Wegel

et al. 2010

Space Telescopes and Instrumentation 2010: Ultraviolet to Gamma Ray

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The Japanese Astro-H mission will include the Soft X-ray Spectrometer (SXS) instrument, whose 36-pixel detector array of ultra-sensitive x-ray microcalorimeters requires cooling to 50 mK. This will be accomplished using a 3-stage adiabatic demagnetization refrigerator (ADR). The design is dictated by the need to operate with full redundancy with both a superfluid helium dewar at 1.3 K or below, and with a 4.5 K Joule-Thomson (JT) cooler. The ADR is configured as a 2-stage unit that is located in a well in the helium tank, and a third stage that is mounted to the top of the helium tank. The third stage is directly connected through two heat switches to the JT cooler and the helium tank, and manages heat flow between the two. When liquid helium is present, the 2-stage ADR operates in a single-shot manner using the superfluid helium as a heat sink. The third stage may be used independently to reduce the time-average heat load on the liquid to extend its lifetime. When the liquid is depleted, the 2nd and 3rd stages operate as a continuous ADR to maintain the helium tank at as low a temperature as possible -expected to be 1.2 K -and the 1st stage cools from that temperature as a single-stage, single-shot ADR. The ADR's design and operating modes are discussed, along with test results of the prototype 3-stage ADR.

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Magnetocaloric Effect of Polycrystal GdLiF4 for Adiabatic Magnetic Refrigeration

Cited by 29 publications

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Applications of the magnetocaloric effect in single-stage, multi-stage and continuous adiabatic demagnetization refrigerators

Applications of the magnetocaloric effect in single-stage, multi-stage and continuous adiabatic demagnetization refrigerators

Magneto Caloric Properties of Polycrystalline Gd₂O₂S for an Adiabatic Demagnetization Refrigerator

Design of a 3-stage ADR for the soft x-ray spectrometer instrument on the ASTRO-H mission

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Magnetocaloric Effect of Polycrystal GdLiF4 for Adiabatic Magnetic Refrigeration

Cited by 29 publications

References 0 publications

Applications of the magnetocaloric effect in single-stage, multi-stage and continuous adiabatic demagnetization refrigerators

Applications of the magnetocaloric effect in single-stage, multi-stage and continuous adiabatic demagnetization refrigerators

Magneto Caloric Properties of Polycrystalline Gd2O2S for an Adiabatic Demagnetization Refrigerator

Design of a 3-stage ADR for the soft x-ray spectrometer instrument on the ASTRO-H mission

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Magneto Caloric Properties of Polycrystalline Gd₂O₂S for an Adiabatic Demagnetization Refrigerator