HNOSS Horizontal Cryostat

HNOSS (Horizontal Nugget for Operation of Superconducting Systems) is a versatile horizontal cryostat system for testing superconducting cavities.

The facility allows users to characterize 1-2 superconducting cavities at a time at either low or high RF power. Each cavity must be equipped with a helium tank.

A project based at HNOSS is expected to last typically for three months. It is estimated that the installation of equipment will take one month, followed by a month of cooling and measurement, and finally a month to warm up the facility so equipment can be removed.

Technical Means

  • Internal dimensions: 1.2 m diameter, 3.3 m length.
  • Range of operation: 1.8 to 4.5 K, 16 to 1250 mbar.
  • Pressure stability at 16 mbar: +/- 0.1 mbar.
  • Cooling power at 1.8 K: 90 W.
  • Internal warm magnetic shielding: mu-metal, 1 mm.
  • Feedthrough flange max size ISO F500 (x5).
  • Cavity vacuum pumping system with ion pump, turbo-molecular pump and oil free roughing pump.
  • Leak detector with oil-free vacuum pumps.
  • Portable clean room (dimensions?).
  • Mechanical and electric workshop services for installation.


  • Test of 352 MHz superconducting spoke cavity with antenna.
  • Test of 352 MHz superconducting spoke cavity with fundamental power coupler and cold tuner system.

Technical Expertise

  • Horizontal positioning of cavity with power coupler.
  • Portable clean room connection of cavity vacuum pumping system.
  • Installation of Cernox and PT100 temperature sensors, electric heaters.
  • Mechanical and electric workshop services for installation and maintenance.
  • Controls and data acquisition.

User Support

Users can choose to participate in the installation work or leave this preparation to facility staff. Facility staff will operate the facility and will be available to advise and assist with testing scenarios. Users can take the lead during the measurement campaign. Logistics support can be arranged through local providers by facility staff.


Interested parties are encouraged to contact the Facility Coordinator before beginning the formal application process with brief details of the test campaign proposal.

Facility Coordinator: Lars Hermansson.

Related Files

HNOSS Cryogenic Scheme
ICB Cryogenic Scheme
Cryogenic Scheme Nomenclature
HNOSS Valve Box Details
ICB Details
Heater Details

Last modified: 2022-09-09