New Vertical Test Facility installed in Daresbury

A new Vertical Test Facility (VTF) developed by a multidisciplinary team of scientists from the Cockcroft Institute has been commissioned at Daresbury Laboratory for the testing of superconducting radio frequency (SRF) cavities at 2K.

The recently completed Vertical Test Facility at Daresbury Laboratory has taken several years to commission. Credit: STFC

Starting next year, the VTF will support an intensive testing schedule as part of the UK’s in-kind contribution to the European Spallation Source (ESS). The ESS, currently under construction in Sweden, will be the world’s most powerful pulsed neutron source.

Key components of the ESS accelerator are the 84 high beta SRF cavities which will be tested by the Cockcroft Institute team at Daresbury. The cavities will be tested for both their accelerating gradient and how efficiently they are able to sustain the radio frequency power used to provide the electric fields for accelerating the particle beam. Fantastic results have been seen in testing of the first prototype cavity.

Up to three cavities at a time can be assembled in the cavity support insert. The insert is mounted inside a 4m deep cryostat. The cryostat itself is housed in a deep well in a concrete bunker to provide radiation shielding. In here, the team can cool the cavities to temperatures less than 2K, and perform a series of tests on each individual cavity.

Some of the Cockcroft Institute team involved in the design and build of Daresbury Laboratory’s unique Vertical Test Facility. Credit: STFC

This VTF has been designed in-house to reduce helium consumption by up to 70% and it recycles the gas to be reused. This represents a significant saving in terms of running costs.

This commissioning represents a significant step forward in the UK’s accelerator testing and reprocessing infrastructure.

The team would like to thank STFC management, as well as international partners at CEA, DESY, ESS, INFN and JLab.