Kohler, Donald (1959) Observations on the lifetimes of the 3.37-Mev 2+ state of Be10 and of the 6.14-Mev 3- state of O16. Dissertation (Ph.D.), California Institute of Technology. http://resolver.caltech.edu/CaltechETD:etd-02022006-093244
NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document.
An upper limit for the lifetime of the 3.37-Mev 2+ state of Be10 has been established by use of a Doppler shift technique. Be10 nuclei were produced by the Be9 (d,p)Be10 reaction and those protons leaving the Be10 in its 3.37-Mev excited state were used to select [...] rays emitted by Be10* nuclei having a well defined recoil velocity. The energy of the [...] rays emitted by these nuclei was determined by scintillation spectroscopy. The experiment was designed to look for a possible difference between the [...]-ray Doppler shifts produced when the recoil nuclei were stopped in a metal foil and when the nuclei were allowed to recoil into vacuum. A small statistically insignificant difference in shift was observed which allowed only an upper limit of about 2.0 x 10(-13) seconds for the half-life [mean life: [...] seconds] to be inferred. This limit to the mean life is compared with theoretical estimates of the lifetime based on different nuclear models.
The lifetime of the 6.14-Mev 3- state of O16 has been measured by means of a recoil technique. The spatial distribution of decays of recoiling O16 nuclei, produced by the F19[...]O16+ reaction, was studied with a highly collimated [...]-ray detector. Comparison with the corresponding results obtained when the [...] nuclei were stopped at the target surface by an evaporated metallic layer provided a convenient means of determining the lifetime. A value for this half-life of (8.6 +/- 4.0) x 10(-12) seconds [mean life: [...] = (1.2 +/- 0.6) x 10(-12) seconds] has been found, consistent with previously established limits. The measured value of the mean life is compared with the theoretical values of the lifetime according to various nuclear models.
|Item Type:||Thesis (Dissertation (Ph.D.))|
|Degree Grantor:||California Institute of Technology|
|Division:||Physics, Mathematics and Astronomy|
|Thesis Availability:||Public (worldwide access)|
|Defense Date:||1 January 1959|
|Default Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Imported from ETD-db|
|Deposited On:||06 Feb 2006|
|Last Modified:||26 Dec 2012 02:29|
- Final Version
See Usage Policy.
Repository Staff Only: item control page