Metastable decay of photoionized niobium clusters: Evaporation vs fission fragmentation

Conference · Wed Jan 01 00:00:00 EST 1986

OSTI ID:6923691

Cole, S K; Liu, K; Riley, S J

The metastable decay of photoionized niobium clusters (Nb/sub n//sup +/) has been observed in a newly constructed cluster beam machine. The decay manifests itself in the time-of-flight (TOF) mass spectrum as an asymmetric broadening of daughter ion peaks. Pulsed ion extraction has been used to measure the decay rate constants and to establish the mechanism of the fragmentation, evaporation and/or fission of the photoionized clusters. It is found that within the experimental time window evaporation dominates for the smaller clusters (n < 15), whereas fission fragmentation becomes facile for 15 < n < 30. The decay rate constants obtained all fall within the range 0.5 - 2.0 x 10/sup 6/ sec/sup -1/. The average kinetic energy release is also determined and is found to be on the order of 5 MeV. 8 refs., 3 figs., 1 tab.

• Research Organization: Argonne National Lab., IL (USA)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 6923691
• Report Number(s): CONF-8610159-3; ON: DE87004314
• Resource Relation: Conference: International symposium on the physics and chemistry of small clusters, Richmond, VA, USA, 28 Oct 1986; Other Information: Portions of this document are illegible in microfiche products
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
NIOBIUM ISOTOPES
DECAY
ISOMERIC NUCLEI
PHOTOIONIZATION
EVAPORATION MODEL
FISSION
FISSION FRAGMENTS
MASS SPECTRA
TIME-OF-FLIGHT METHOD
IONIZATION
ISOTOPES
MATHEMATICAL MODELS
NUCLEAR FRAGMENTS
NUCLEAR MODELS
NUCLEAR REACTIONS
NUCLEI
SPECTRA
651720* - Nuclear Properties &amp; Reactions
A=90-149
Experimental