Cooling device with controllable evaporation temperature

Abstract

A cooling device for cooling a test sample has at least two cascade cooling stages, each with at least one coolant line, one compressor ( 1.1, 2.1 ), one relief throttle ( 1.5 ), one evaporator ( 6, 7 ) and one liquefier ( 3, 6 ). The coolant line is divided into n partial lines (A, B) between the compressor ( 2.1 ) and the liquefier ( 6 ) of the last cascade cooling stage, wherein n≧2. Each divided n partial line (A, B) has a valve ( 2.7, 2.8 ) and an individual relief throttle ( 2.5, 2.6 ). The divided partial lines (A, B) are connected to the evaporator ( 7 ) of the last cascade cooling stage. This represents a simple possibility of adjusting the cooling temperature without using valves that must be adjusted in a cold state, since such valves are complex and expensive.

1 . A cooling device for cooling a test sample, the cooling device comprising:
 at least one first cascade non-final cooling stage, said first non-final cooling stage having at least one first coolant line, a first compressor, a first relief throttle, a first evaporator and a first liquefier; and   a second final cascade cooling stage, said second final cascade cooling stage having at least one second coolant line, a second compressor, a second relief throttle, a second evaporator and a second liquefier, said second coolant line being divided into n partial lines between said second compressor and said second liquefier, wherein n≧2, said divided n partial lines structured for individual blockage thereof and independently of an other by means of at least n−1 valves, each divided partial line having an individual relief throttle, wherein said divided partial lines are connected to said second evaporator.   
     
     
         2 . The cooling device of  claim 1 , wherein said divided partial lines are guided in parallel through said second liquefier. 
     
     
         3 . The cooling device of  claim 1 , wherein said second evaporator is designed as a heat exchanger, a gas to be cooled entering said heat exchanger through a gas inlet, dissipates heat, exits said heat exchanger again through a gas outlet and is guided to the test sample for cooling thereof. 
     
     
         4 . The cooling device of  claim 1 , wherein the cooling device is structured for use in a nuclear magnetic resonance spectroscopy apparatus. 
     
     
         5 . The cooling device of  claim 1 , wherein the cooling device is structured for use in an X-ray spectroscopy apparatus. 
     
     
         6 . The cooling device of  claim 1 , wherein the cooling device is structured for use in an EPR apparatus.