Mass Spectrographic Assignment of Rubidium Isotopes,
Abstract
We have used a mass spectrograph to investigate rubidium isotopes produced by bombardment of bromine (ammonium bromide) with helium ions in the Berkeley 60-inch and 184-inch cyclotrons. The 60 deg deflection spectrograph is similar to that of Lewis and Hayden but with larger dimensions and all-metal construction. In each bombardment with 20 to 100 Mev helium ions, there was a good yield of rubidium activity with half-life of about 6 hours. The rubidium activities were separated from the target material, using 20 to 30 micrograms of inactive rubidium carrier, and divided into two portions. One part was further purified and used for decay and absorption measurements. The other major portion was placed on the tungsten filament of the mass spectrograph as the nitrate or chloride. The Rb(+) ions produced by heating this filament were analyzed by the instrument and caught on a photographic plate. The mass scale was fixed by the lines of stable Rb(85) and Rb(87). Lines at masses 81 and 82 were shown to be radioactive both by the photographic transfer technique and by counting with a Geiger counter provided with a narrow slit. With 80-Mev helium ions, 5.0-hour Rb(81) predominated in the mixture, and with 20-Mev helium ions, almost-pure 6.3-hour Rb(82) was obtained. Otherwise, the similar half-lives would have made characterization of the radiations, which are listed in Table 1, very difficult. The signs of the particles were determined with a crude 180 deg -deflection beta spectrograph. The energies listed in Table 1 were obtained with this instrument or from absorption measurements with aluminum, beryllium, or lead, as indicated. p2
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1948
- Accession Number
- ADA321431
Entities
People
- D. C. Karraker
- David H. Templeton
- Frederick L. Reynolds
Organizations
- Oak Ridge National Laboratory