Cryocooler and method for operating cryocooler

Abstract

A cryocooler includes: a compressor; a plurality of cold heads connected in parallel to the compressor; a pressure sensor that measures a pressure of a working gas on a supply side from the compressor to the plurality of cold heads or on a collection side from the plurality of cold heads to the compressor; and a controller configured to acquire, for each of the plurality of cold heads, individual pressure waveform data measured by the pressure sensor when the cold head is individually operated, and to operate the plurality of cold heads simultaneously and asynchronously based on the individual pressure waveform data of the plurality of cold heads.

What is claimed is: 
     
         1 . A cryocooler comprising:
 a compressor;   a plurality of cold heads connected in parallel to the compressor;   a pressure sensor that measures a pressure of a working gas on a supply side from the compressor to the plurality of cold heads or on a collection side from the plurality of cold heads to the compressor; and   a controller configured to:
 acquire, for each of the plurality of cold heads, individual pressure waveform data measured by the pressure sensor when that cold head is individually operated, and 
 operate the plurality of cold heads simultaneously and asynchronously based on the individual pressure waveform data of the plurality of cold heads. 
   
     
     
         2 . The cryocooler according to  claim 1 , wherein
 the controller is configured to operate the plurality of cold heads simultaneously and asynchronously based on comparison between the individual pressure waveform data of the plurality of cold heads.   
     
     
         3 . The cryocooler according to  claim 1 , wherein
 the controller is configured to:
 acquire total pressure waveform data measured by the pressure sensor when the plurality of cold heads are simultaneously operated, 
 acquire a total pressure amplitude from the total pressure waveform data, 
 acquire a total sum of individual pressure amplitudes from the individual pressure waveform data of the plurality of cold heads, and 
 operate the plurality of cold heads simultaneously and asynchronously based on comparison between the total pressure amplitude and the total sum of the individual pressure amplitudes. 
   
     
     
         4 . A method for operating a cryocooler, in which the cryocooler includes a compressor, and a plurality of cold heads connected in parallel to the compressor, the method comprising:
 for each of the plurality of cold heads, measuring a pressure of a working gas on a supply side from the compressor to the plurality of cold heads or on a collection side from the plurality of cold heads to the compressor during individual operation of that cold head; and   operating the plurality of cold heads simultaneously and asynchronously based on a pressure waveform obtained by measurement.