The RaD-RaE (or Pb210-Bi210) source can also be used as an alpha source. We find ours useful for checking an alpha scintillation probe. -- P. Sridhar Rao, Radiology, CWRU / Univ Hosp of Cleveland, Cleveland, Ohio. Tel: 216-844-1295. Fax: 216-844-5922. E-mail: psr@po.cwru.edu