Gaithersburg NIST

Organisation: National Institute of Standards and Technology

Installation: NBSR, operational since 1967

Type: pool reactor, 20 MW, HEU, D2O reflector, th=4·1014 n/cms,

Address: 100 Bureau Drive
Gaithersburg, MD 20899, USA

Home page:

Contact: Dr. Robert ("Bob") E. Williams

Phone / fax: +1 301-975-6876, fax: +1 301-921-9847




CNS: operating since 1995

moderator: H2 temperature: 20 K

effective volume: 5 L phase: liquid

pressure: 100 kPa power: 1200 W

material: chamber: Al 6061 vacuum thimble: Al 6061

refrigerator: CVI (Columbus OHIO),1 screw,

heat removal: gravity (thermal siphon)

performance: see (April 2002)


remark: reactor does not need to shut down in case of CNS failure (room temperature cooling loop).

recent publications: Proc. IGORR9 (Sydney 2003): SNS-04 (session 4)

Symposium in Commemoration of the 10th Anniversary of HANARO -

Daejeon, Korea, April 2005: "Issues in the Design of a Cold Neutron Source" by Mike Rowe (now retired).


UCN group around M. Scott Dewey and Geoffrey Greene, P.R. Huffman

On a cold neutron beam: Superfluid 4He, cooled below 1K, magnetic confinement,

Home page:

recent publication: "Measurement of the neutron lifetime by counting trapped protons in a cold neutron beam"
M. Scott Dewey at the 5th UCN/CN Workshop in Peterhof (RU) 2005

See also "Progress towards Precision Measurement of the Neutron Lifetime using Magnetically Trapped Ultracold Neutrons" by L. Yang at same workshop 2005.