Regenerator, GM type refrigerator and pulse tube refrigerator

摘要

A helium-cooling type regenerator includes first and second storage spaces. The first storage space is disposed in a region on a high-temperature side, and accommodates the regenerator material whose pressure is P1. The second storage space is disposed in a region on a low-temperature side, and accommodates the regenerator material whose pressure is P2, which is less than P1. A specific heat in the case where a pressure of the regenerator material accommodated in the first storage space is P2 is less than that in the case where the pressure of the regenerator material is P1, and a specific heat in the case where a pressure of the regenerator material accommodated in the second storage space is P1 is less than that in the case where the pressure of the regenerator material is P2.