Speaker
Description
Engineering validation activities for the IFMIF accelerator concept—conducted through the Linear IFMIF Prototype Accelerator (LIPAc)—are ongoing in Rokkasho, Aomori, under the Broader Approach (BA) framework. In the LIPAc system, installation of the Superconducting Radio Frequency (SRF) linac and integration with the cryogenic system are currently in progress.
During the cryogenic cooling down tests performed prior to integrating the SRF cryomodule in September of 2018 and April of 2024, several technical issues were encountered that could affect overall availability. For example, an unexpected shutdown of the helium compressor occurred when the common cooling water system was temporarily stopped for cleaning of the cooling water filter, resulting in an unintended warm up of the cryogenic system. To mitigate these risks, a dedicated chiller for the helium compressor was designed and is now being installed. Theoretically, we can keep the continuous cryogenic operation without compressor stop.
In addition, a second helium gas buffer tank was constructed, and third tank construction is planned to ensure stable operation amid the ongoing global helium shortage by reducing the frequency of helium delivery and improving onsite availability.
The experience gained and the countermeasures implemented during the commissioning of the cryogenic system provide valuable insights for improving the availability of high intensity neutron source linac.