Cryopump system

Abstract

A cryopump system includes a temperature measurement unit configured to measure temperatures of a first stage part and a second stage part of a cryopump, respectively, a monitoring unit configured to monitor whether the temperature of the second stage part reaches a predetermined second reference temperature and a controller configured to gradually increase a motor rotational speed of a cooler of the cryopump whenever the temperature of the second stage part reaches the predetermined second reference temperature.

We claim: 
     
         1 . A cryopump system, comprising:
 a temperature measurement unit configured to measure temperatures of a first stage part and a second stage part of a cryopump, respectively;   a monitoring unit configured to monitor whether the temperature of the second stage part reaches a predetermined second reference temperature; and   a controller configured to gradually increase a motor rotational speed of a cooler of the cryopump whenever the temperature of the second stage part reaches the predetermined second reference temperature.   
     
     
         2 . The cryopump system of  claim 1 ,
 wherein the monitoring unit monitors whether a temperature of the first stage part is maintained at a predetermined first reference temperature while a first heater configured to heat the first stage part is in an OFF state.   
     
     
         3 . The cryopump system of  claim 2 ,
 wherein the controller gradually increases the motor rotational speed of the cooler of the cryopump whenever the temperature of the first stage part is higher than the predetermined first reference temperature while the first heater is in the OFF state.   
     
     
         4 . The cryopump system of  claim 1 ,
 wherein an initial motor rotational speed of the cooler is in the range of from 40 rpm to 50 rpm, and   the controller increases the motor rotational speed of the cooler to between 80 rpm and 90 rpm.   
     
     
         5 . The cryopump system of  claim 1 ,
 wherein the controller increases the motor rotational speed of the cooler by from 5 rpm to 10 rpm whenever the temperature of the second stage part reaches the predetermined second reference temperature.   
     
     
         6 . The cryopump system of  claim 1 ,
 wherein the predetermined second reference temperature is from 17K to 20K.