Workshop on Beta-delayed neutron emitters: evaluation and measurements

Beta-delayed neutron emission in fission products had already been discoverd a few months after fission itself. Ever since then, this decay mode has been studied intensively, as the data are essential input values for technical applications as fission reactors. Accordingly, there exists qite a lot of compilations and evaluations dealing with asüects of this decay mode as the emission...

Based on Audi's 2011 interim mass adjustment file, lists of all the known nuclides have been extracted for which B-N, B-2N and B-3N decays are possible. Those for which measurements exist are indicated in tabular files as well as interactive chart of nuclides. Evaluation of B-N and B-2N data for about ten nuclides in the lowest mass region will be presented.

The decay sub-library for ENDF/BVII.1 was recently released at the NNDC. This incorporates new data, whenever available, updated Q values, and the latest electron conversion calcuations. Considerable effort was spent reviewing each decay set, and benchmarking the performance of the library which contains data for 3817 isotopes including isomeric states. For beta-delayed neutron...

The decay studies of fission products performed at the Holifield Radioactive Ion Beam Facility operating between 1996 and 2012 at Oak Ridge will be presented. The published results include beta-delayed neutron branching ratio measurements for several Cu, Zn and Ga isotopes. New spectroscopy measurements reaching up to 79Cu, 83Zn, 86Ga, 86Ge and 87As will be discussed. The selected results...

Incomplete and inadequate decay data for the short-lived fission products restrict applicability of summation codes in estimating the reactor decay heat for the short cooling times or deriving the absolute delayed neutron yields. The beta-decay properties of a much broader set of the very neutron-rich nuclei are of need for the astrophysical r-process modeling. The vast majority of these...

We have calculated the average number of delayed neutrons per fission (nu-bars) for neutron induced fission on a number of actinide targets. Additionally, we have calculated the neutron energy spectra and the so-called six-group parameters. The influence of the Pn and T1/2 data on these calculations will be discussed.

We explore the systematics of beta-delayed neutron emission probabilities both globally and in regions relevant to applications, such as decay heat calculations. Traditionally, correlations were sought by investigating the P$_n$ value as a function of the Q value of the decay (or some relation involving Q). Here, we present systematics of the ratio P$_n$/T{_1/2} and find a strong...

Modern radioactive-beam facilities are capable of producing intense sources that are ideal for beta-decay studies. At the TRIUMF-ISAC facility, we have a strong program of nuclear structure studies utilizing beta-decay and the 8pi spectrometer. Part of our program have examined systems close to stability, concentrating on very-high-statistics measurements, while another component of the...

Reliable measurements of beta-delayed neutron properties can be performed with precision by confining radioactive ions in an ion trap. When a radioactive ion decays in the trap, the recoil-daughter nucleus and emitted particles emerge from the <1 mm^3 trap volume without scattering and propagate unobstructed through vacuum. These properties allow the momentum and energy of the emitted neutron...

A new neutron counter BELEN (BEta deLayEd Neutron) is being developed within the DESPEC-NUSTAR experiment for the future FAIR facility by the UPC-Barcelona, IFIC-Valencia and GSI-Darmstadt/Giessen U. collaboration. Meanwhile the detector is being employed at several installations for the study of beta-delayed neutron emission probabilities Pn.. The commissioning of the detector and first...

The beta-decay study of neutron rich nuclei is a priority of the Radioactive Ion Beam Factory (RIBF). The unique capabilities of RIBF to produce and identify extremely neutron rich nuclei produced by in-flight fission of a 345 MeV/nucleon 238U beam has been proven for example in Ref. [1], and the first successful beta-decay experiment in the 110Zr regions was performed in 2008 with 238U beam...