| Abstract: | A mathematical model of the cooling of a continuous-flow cryostat which takes into account real values of the specific and latent heat of the cryogenic fluid and of the specific heat of the cryostat material is presented. The amount of liquid in the cooling fluid and four parasitic heat flows, caused by radiation and heat conduction in the construction materials and in the rest gas in the vacuum insulation, are also taken into account. The influence of different model parameters on performance, particularly in the non-stationary regime, is demonstrated by means of numerical solutions of the modelling equations. A quantitative criterion which assesses the properties of the planned cryostat, is formulated. The theoretical conclusions are compared with measurements performed on a continuous flow helium cryostat. |
