Speaker
Description
The AGOR superconducting cyclotron at the Particle Therapy Research Center (PARTREC) in The Netherlands has been operational with its main coils kept continually at cryogenic temperatures since the mid-1990s. A Sulzer TCF50 Liquefier is used to supply liquid helium (LHe) to operate the cyclotron’s two superconducting main coils and two superconducting extraction channels. The extraction channels are routinely warmed to room temperature. When not operating the cyclotron no LHe is required in the cryostat housing the coils. However, in order to keep the cyclotron’s main coils adequately cooled to avoid damage or warping of the accelerator from thermal stresses, the liquefier supplies cooled helium gas (GHe) across the coils during non-operational periods. Since AGOR’s commissioning, it has been a policy to forego much of the regular, preventative maintenance to the cryogenics system that is common in other facilities to avoid shutting down the liquefier for more than two or three consecutive days. A longer shutdown of the liquefier could lead to long downtimes and could potentially cause catastrophic damage if the coils of the superconducting magnet warm up in an uncontrolled way. For this reason, we can offer the cryogenics community a unique insight into a cryogenics system that has been run almost continuously since the mid-1990s. We will report on many years of experience with our system and on findings that come from recent maintenance activities that became necessary following a persistent unstable behavior of the system that arose in 2018.
| Submitters Country | The Netherlands |
|---|
