Cryogenic cooling system with plural mechanical refrigerators

Abstract

A cryogenic cooling system comprises a vacuum enclosure. A first mechanical refrigerator comprises first upper (104) and lower (106) cooling stages in said vacuum enclosure. A first conduit (402) passes a first stream of fluid cooling medium towards a working region. At least one thermal coupling (403) of said first conduit (402) and said first mechanical refrigerator (401) cools said fluid cooling medium on its way towards said working region. A second mechanical refrigerator (404) comprises second upper (405) and lower (406) cooling stages in said vacuum enclosure. At least one thermal coupling (407) of said first conduit (402) and said second mechanical refrigerator (404) cools said fluid cooling medium further after said at least one thermal coupling (403) of said first conduit (402) and said first mechanical refrigerator (401) on the path of said first stream of fluid cooling medium.