Search results for "Isotopes of bromine"

Isomeric Yield Ratios of 134I and 136I and Independent Fractional Yields of some Halogen Isotopes in the Fission of 232Th with Reactor Neutrons

1990

Conversion coefficients of the isomeric state in 72Br

2010

In order to determine the Gamow‐Teller strength distribution for the N  =  Z nucleus 72Kr an experiment was performed with a Total Absorption Gamma Spectrometer. To fully accomplish this task it is crucial to determine the multipolarity of the low energy transitions as the spin‐parity of the daughter ground state has been debated. This is done by experimental determination of the conversion coefficients. Preliminary results for the multipolarity and conversion coefficients of the transition connecting the isomeric state at 101 keV with the 72Br ground state are presented.

Overlappingβdecay and resonance neutron spectroscopy of levels inKr87

1983

Energy levels in $^{87}\mathrm{Kr}$ have been studied, with special emphasis on the unbound region, using two different methods. The first method comprises neutron capture and transmission measurements on an enriched gas target of $^{86}\mathrm{Kr}$ using neutron time-of-flight techniques. In this way, neutron widths were determined for 39 resonances below 400 keV and capture areas for 14 resonances below 90 keV. The second method is a decay study of 56-s $^{87}\mathrm{Br}$ in which a level scheme for $^{87}\mathrm{Kr}$ has been established that shows 126 levels in the bound and 12 levels in the unbound region. A detailed comparison amongst the neutron resonance, the $\ensuremath{\gamma}$-r…

Total absorption γ -ray spectroscopy of the β -delayed neutron emitters Br87 , Br88 , and Rb94

2017

We investigate the decay of 87,88Br and 94Rb using total absorption γ -ray spectroscopy. These important fission products are β-delayed neutron emitters. Our data show considerable βγ intensity, so far unobserved in high-resolution γ -ray spectroscopy, from states at high excitation energy. We also find significant differences with the β intensity that can be deduced from existing measurements of the β spectrum. We evaluate the impact of the present data on reactor decay heat using summation calculations. Although the effect is relatively small it helps to reduce the discrepancy between calculations and integral measurements of the photon component for 235U fission at cooling times in the r…

Intense mass-separated beams of halogens and beta-delayed neutron emission from heavy bromine isotopes

1984

Improved production yields of short-lived halogens were obtained from a ThO2 target, irradiated with 600 MeV protons, in combination with a negative surface ionization source. Mass-separated samples were studied by decay spectroscopy. Production yields of radioactive isotopes of chlorine, bromine, iodine and astatine are presented. Half-lives and relative neutron emission probabilities were measured for the heavy bromine isotopes89−92Br. Normalizing to earlier publishedPn values for89Br, the results are:89Br (4.30±0.14s,P n =13.6±0.8%),90Br (1.92±0.06s,P n =24.8±1.5%),91Br (0.53 ±0.03 s,P n =30.1 ±2.1%), and92Br (0.31 ±0.02 s,P n =34.6±2.5%). Energy spectra ofβ-delayed neutrons were measure…

Mass spectra of halogenated esters 6—Methyl esters of some trihalogenated propanoic and butanoic acids

1984

The mass spectral fragmentation of trihalogenated methyl esters, formed in the reactions of monochlorinated methyl propenoates and 2-butenoates with Cl2, BrCl and Br2, have been investigated. In most cases α-cleavage gives the base peak, [COOCH3]+, the peaks originating from the subsequent losses of one or two halogen atoms also being abundant. The primary loss of a halogen atom is more prominent in the C4 derivatives, Br˙ and Cl˙ being preferentially lost from the 2- and 3-positions, respectively. The McLafferty rearrangement yields in one case the base peak; the 2-halo compounds could in general be distinguished by that fragmentation. Typical for all 2-bromo-substituted methyl butanoates …