A heat dissipating device includes a carrier, a magnetic driving module installed on the carrier, two fixing rivets, and two swing structures. Each of the swing structures includes a blade, a positioning rivet, and a magnetic actuation fixed on the blade by using the positioning rivet. The two blades are respectively fixed on two opposite outer sides of the carrier by using the two fixing rivets, and the two blades are parallel to each other. When the magnetic driving module generates a magnetic field, the two magnetic actuations are moved by the magnetic field to swing the two blades.

A heat dissipating device includes a carrier, a magnetic driving module installed on the carrier, two fixing rivets, and two swing structures. Each of the swing structures includes a blade, a positioning rivet, and a magnetic actuation fixed on the blade by using the positioning rivet. The two blades are respectively fixed on two opposite outer sides of the carrier by using the two fixing rivets, and the two blades are parallel to each other. When the magnetic driving module generates a magnetic field, the two magnetic actuations are moved by the magnetic field to swing the two blades.

A heat regenerating material particle of an embodiment contains a heat regenerating substance having a maximum value of specific heat at a temperature of 20 K or less is 0.3 J/cm.sup.3.Math.K or more, and one metal element selected from the group consisting of calcium (Ca), magnesium (Mg), beryllium (Be), strontium (Sr), aluminum (Al), iron (Fe), copper (Cu), nickel (Ni), and cobalt (Co). The heat regenerating material particle includes a first region and a second region, the second region is closer to an outer edge of the heat regenerating material particle than the first region, and the second region has a higher concentration of the metal element than the first region.

A two-stage heat regenerating cryogenic refrigerator may include: a vacuum vessel; a first and second cylinder in the vessel; the second cylinder coaxially connected to the first cylinder; a 1.sup.st regenerator in the first cylinder and accommodating heat regenerating material (HRM) 1; and a second regenerator in the 2.sup.nd cylinder accommodating HRM 2, HRM 2 including HRM particles, each HRM particle including a metal element and a heat regenerating substance including an oxide or oxysulfide and having a maximum specific heat at ≤20 K of ≥0.3 J/cm.sup.3.Math.K; each HRM particle including a 1.sup.st and 2.sup.nd region, the 2.sup.nd region being closer to each HRM particle's outer edge than the 1.sup.st, and the 2.sup.nd region having a higher metal element concentration than the 1.sup.st, the 1.sup.st and 2.sup.nd region containing the heat regenerating substance.

A two-stage heat regenerating cryogenic refrigerator may include: a vacuum vessel; a first and second cylinder in the vessel; the second cylinder coaxially connected to the first cylinder; a first regenerator in the first cylinder, the first regenerator accommodating heat regenerating material (HRM) 1; and a second regenerator in the second cylinder accommodating HRM 2, HRM 2 including plural HRM particles, each HRM particle including a heat regenerating substance having a maximum value of specific heat at a temperature of 20 K or less of 0.3 J/cm3.Math.K or more and a metal element; each HRM particle including a first and second region, the second region being closer to each HRM particle's outer edge than the first, and the second region having a metal element higher concentration than the first, the first and second region containing the heat regenerating substance, and the heat regenerating substance contains an oxide or oxysulfide component.

A method may produce a heat regenerating material particle, including: preparing a slurry by adding a powder of the heat regenerating substance to an alginic acid aqueous solution and mixing the powder of the heat regenerating substance and the aqueous alginic acid solution; and forming a particle by gelling the slurry by dropping the slurry into a gelling solution. The gelling solution may include a metal element including calcium (Ca), manganese (Mn), magnesium (Mg) beryllium (Be), strontium (Sr), aluminum (Al), iron (Fe), copper (Cu), nickel (Ni), and cobalt (Co). The forming may involve controlling the gelation time so that a concentration of the metal element in a first region of the particle becomes lower than a concentration of the metal element in a second region. The second region may be closer to an outer edge of the particle compared to the first region.

A method may produce a two-stage heat regenerating cryogenic refrigerator including a vacuum vessel, first and second cylinder disposed in the vessel, the second cylinder coaxially connected to the first cylinder, and first and second regenerator respectively disposed in the first and second cylinder. The method may include: accommodating a first heat regenerating material (HRM) in the first regenerator; and filling a plurality of HRM particles in the second regenerator. The HRM particles may be a second HRM, each of the HRM particles including an oxide or oxysulfide heat regenerating substance having a maximum value of specific heat at a temperature of 20 K of 0.3+ J/cm3.Math.K and Ca, Mn, Mg, Be, Sr, Al, Fe, Cu, Ni, and/or Co. Each of the HRM particles may include a first and second region, the second region being closer to an HRM particle outer edge than the first region.

A heat regenerating material particle of an embodiment contains a heat regenerating substance having a maximum value of specific heat at a temperature of 20 K or less is 0.3 J/cm.sup.3.Math.K or more, and one metal element selected from the group consisting of calcium (Ca), magnesium (Mg), beryllium (Be), strontium (Sr), aluminum (Al), iron (Fe), copper (Cu), nickel (Ni), and cobalt (Co). The heat regenerating material particle includes a first region and a second region, the second region is closer to an outer edge of the heat regenerating material particle than the first region, and the second region has a higher concentration of the metal element than the first region.

A cooling system for an electronic circuit package is provided. The cooling system includes a heat transfer plate positioned in thermal contact with an electronic circuit package surface and forming the bottom surface of an evaporative region of the cooling system. The cooling system also includes a plurality of condensing tubes in fluid communication with, and extending away from, the evaporative region, such that the evaporative region and the condensing tubes together form a single, uninterrupted, sealed enclosure. The cooling system also includes a fluid within the sealed enclosure. The cooling system also includes a plurality of spacers filling gaps between the heat transfer plate and the condensing tubes, such that each spacer is configured as an independent component to allow the passage of fluid through the interior space of each spacer. The cooling system also includes a plurality of wicks, where each wick is positioned partially within a corresponding spacer to which it is fluidically coupled.

A plate flatness adjusting device includes at least one tendon, an accommodation portion, and a tensile strength adjuster. The at least one tendon penetrates a through-hole of a plate and has lateral ends protruding outside of the plate. The accommodation portion accommodates the lateral ends of the at least one tendon. The tensile strength adjuster is coupled to the accommodation portion to adjust a tensile strength of the at least one tendon. The adjusted tensile strength adjusts a degree of flatness of the plate.