Cryostat arrangement with a vacuum container and an object to be cooled, with evacuable cavity

A cryostat comprising:

• (a) a vacuum container;
• and
• (b) an object to be cooled,
• wherein the object to be cooled is arranged inside the vacuum container,
• wherein the vacuum container further comprises a neck tube, leading to the object to be cooled,
• wherein a cooling arm of a cold head is arranged at least partly in the neck tube,
• wherein a closed cavity is formed around the cooling arm, being sealed off fluid-tight from the object to be cooled, and
• wherein the cavity in normal operation is filled at least partly with a first cryogenic fluid;
• (c) a first thermal coupling component for thermal coupling of the first cryogenic fluid in the cavity to the object to be cooled,
• (d) a pump device, to which the cavity is connected, and with which the cavity is configured to be evacuated upon failure of the cooling function of the cold head;
• and
• (e) a monitoring device, which monitors the cooling function of the cold head, and which is configured to automatically activate the pump device upon failure of the cooling function of the cold head, so that the cavity is evacuated.