North Korea received its B-25 Betatron facility from the Soviet Union in 1966 as a part of the 1959 agreement on "the peaceful use of atomic energy," which provided for Soviet assistance in establishing a North Korean nuclear research institute.[2] The Betatron was designed as a gamma radiography facility, and it has been used as a pulsed neutron source to measure cross sections.[3]

Sources:
[1] Gregory Karouv, “A Technical History of Soviet-North Korean Nuclear Relations,” in James Clay Moltz and Alexandre Y. Mansourov, eds., The North Korean Nuclear Program: Security, Strategy, and New Perspectives from Russia (New York: Routledge, 2000), p. 17.
[2] Il-Young Kim and Lakhvinder Singh, “The North Korean Nuclear Program and External Connections,” Korean Institute for Defense Analyses, Spring 2004, www.kida.re.kr; Bertil Lintner, “Pyongyang's 60-year Obsession,” Asia Times, 10 October 2006, www.atimes.com.
[3] Gregory Karouv, “A Technical History of Soviet-North Korean Nuclear Relations,” in James Clay Moltz and Alexandre Y. Mansourov, eds., The North Korean Nuclear Program: Security, Strategy, and New Perspectives from Russia (New York: Routledge, 2000), p. 17.