Pulse tube cryocooler and method of manufacturing pulse tube cryocooler

A pulse tube cryocooler comprising:

• a pulse tube that includes a tube inner space;
• and
• an integral flow straightener disposed at at least one of a low-temperature end and a high-temperature end of the pulse tube and comprising:
• a flow straightening layer disposed to face the tube inner space so as to straighten a refrigerant gas flow from the tube inner space or into the tube inner space, and
• a heat exchange layer formed integrally with the flow straightening layer outside the flow straightening layer with respect to the tube inner space so as to exchange heat with the refrigerant gas flow by contact with the refrigerant gas flow, wherein the flow straightening layer includes a plurality of protrusions that protrude from the heat exchange layer toward the tube inner space,
• wherein the heat exchange layer comprises:
• a plurality of heat exchange walls that extends parallel to a first in-plane direction of the heat exchange layer, wherein the plurality of heat exchange walls is disposed alternately with a plurality of heat exchange slits in a second in-plane direction of the heat exchange layer,
• wherein the second in-plane direction of the heat exchange layer is orthogonal to the first in-plane direction of the heat exchange layer;
• wherein the plurality of heat exchange slits penetrates the heat exchange layer in an extending direction of the pulse tube;
• wherein the plurality of heat exchanges slits extends parallel to the first in-plane direction of the heat exchange layer, the first in-plane direction of the heat exchange layer being orthogonal to the extending direction of the pulse tube, and
• wherein the plurality of protrusions protrude from each of the plurality of heat exchange walls toward the tube inner space and are lined up in the first in-plane direction on each heat exchange wall.