arXiv subjects

Erik Andersson Sundén

Publications and source records attributed to Erik Andersson Sundén.

2 recordsLinked to original sources

arXiv2026

NESSA: a compact 14 MeV D-T neutron source facility at Uppsala University

The NESSA (Neutron Source in Uppsala) facility hosts a compact 14 MeV deuterium-tritium sealed tube neutron generator at the Ångström Laboratory, Uppsala University. The generator, housed in a bunker inside the FREIA hall, reaches a maximum yield of $4.7\times10^{8}$ n/s. This paper describes the facility: the generator, the bunker and its shielding, the detector systems, and the Monte Carlo models used to characterize the neutron field. We also report the first commissioning measurements: yield calibration with $^{93}$Nb activation foils, fission chamber response at two positions, and simulated air and structural activation. Initial indium foil activations and single event effect (SEE) tests on silicon devices are also presented. The facility will be used for nuclear data measurements, neutron detector response studies, moderation and thermalization experiments, irradiation testing of electronics as well as for training and education.

physics.ins-det↗

arXiv2017

Defective fission correlation data from the 2E-2v method

The double-energy double-velocity ($2E$-$2v$) method allows assessing fission-fragment mass yields prior to and after prompt neutron emission with high resolution. It is, therefore, considered as a complementary technique to assess average prompt neutron multiplicity as a function of fragment properties. We have studied the intrinsic features of the $2E$-$2v$ method by means of event-wise generated fission-fragment data and found severe short-comings in the method itself as well as in some common practice of application. We find that the $2E$-$2v$ method leads to large deviations in the correlation between the prompt neutron multiplicity and pre-neutron mass, which deforms and exaggerates the so called `sawtooth' shape of $\barν(A)$. We have identified the treatment of prompt neutron emission from the fragments as the origin of the problem. The intrinsic nature of this deficiency, risk to render $2E$-$2v$ experiments much less interesting. We suggest a method to correct the $2E$-$2v$ data, and recommend applying this method to previous data acquired in $2E$-$2v$ experiments, as well.

physics.ins-det↗