| 摘要 |
<p>To ensure that only liquid helium is delivered to a cryostat during liquid helium refill, the arrangement automatically diverts hot gas which is produced during cooling of the transfer tube, away from the cryostat. The arrangement comprises a three way valve (4) which is operated by pressure variations as a result of cooling part of an enclosed volume of helium gas (7,15) to a temperature near the normal boiling point of the liquid at atmospheric pressure. The arrangement provides the advantage in that the transfer of helium to a cryostat now becomes very much a less skilled operation. <IMAGE></p> |
