A new Vertical Test Facility (VTF) has been commissioned at Daresbury Laboratory – the result of extensive work by a multidisciplinary team over a number of years.
The VTF provides the UK with the ability to test superconducting radio frequency (SRF) cavities, which are the accelerating structures at the heart of virtually all modern high-energy particle accelerators.
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.
A key component of the ESS accelerator are the 84 high beta SRF cavities which will be tested by the 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. Measurements agree within 10% to those made in a conventional VTF at an internationally recognised European laboratory.
Caption: Some of the STFC team involved in the design and build of Daresbury Laboratory’s unique Vertical Test Facility.
Up to three cavities at a time can be assembled in the cavity support insert.
The insert is mounted inside a 4m deep cryostat – a machine which maintains very cold temperatures. 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 two degrees above absolute zero, and perform a series of tests on each individual cavity.
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 and is a great achievement for the team at Daresbury.
The team would like to thank STFC management, as well as international partners at CEA, DESY, ESS, INFN and JLab.
Last updated: 04 September 2019