Presented here are results of simulations of neutron background performed for a time projection chamber acting as a particle dark matter detector in an underground laboratory. The investigated background includes neutrons from rock and detector components, generated via spontaneous fission and (α,n) reactions, as well as those due to cosmic-ray muons. Neutrons were propagated to the sensitive v...

Tens of MeV proton beams have been generated by interactions of the VULCAN petawatt laser with foil targets and used to induce nuclear reactions in zinc and boron samples. The numbers of C, Ga, Ga, Ga, Cu, Zn, Zn, and Zn nuclei have been measured and used to determine the proton energy spectrum. It is known that sp ,nd reactions provide an important method for producing neutron sources and in t...

In proton radiation therapy nuclear reactions of highenergy protons hitting beam line components (e.g. collimators or other beam shaping devices) lead to the production of secondary neutrons which may result in significant neutron dose equivalent values (typically of the order of mSv per treatment Gy), depending on the treatment techniques [1]. For scanning devices the neutron dose contribution...

The investigation of boron biodistribution by neutron induced autoradiography was performed using a CR-39 etched track detector. Calibration samples, made of boronated chicken liver, and freeze-dried mouse tissue samples were irradiated both with thermal and cold neutrons. Digital images were made on the basis of track densities, with the selection of tracks due to 10B(n, alpha)7Li reaction. A ...

If the Standard Model is correct, and fundamental fermions exist only in the three generations, then the CKM matrix should be unitary. However, there remain questions over 2+ standard deviations from unitarity in the various data sets, in part from the value of the neutron lifetime. We discuss a simple space-based experiment that, at an orbit height of 500 km above Earth, would measure the kine...

Rotating and magnetized protoneutron stars (PNSs) may drive relativistic magneto-centrifugally accelerated winds as they cool immediately after core collapse. The wind fluid near the star is composed of neutrons and protons, and the neutrons become relativistic while collisionally coupled with the ions. Here, we argue that the neutrons in the flow eventually undergo inelastic collisions around ...

The neutrino energy emission rate due to formation of Cooper pairs of neutrons and protons in the superfluid cores of neutron stars is studied. The cases of singlet-state pairing with isotropic superfluid gap and triplet-state pairing with anisotropic gap are analysed. The neutrino emission due to the singlet-state pairing of protons is found to be greatly suppressed with respect to the cases o...

A new neutron time-of-flight (nTOF) detector for fuel-areal-density measurements in cryogenic DT implosions was installed on the OMEGA Laser System. The nTOF detector has a cylindrical thin-wall, stainless-steel, 8-in.-diam, 4-in.-thick cavity filled with an oxygenated liquid xylene scintillator. Four gated photomultiplier tubes (PMTs) with different gains are used to measure primary DT and D2 ...

The customary picture of the fireball deceleration by an external medium neglects two physical agents in the problem that are important at radii R < 10 cm: a radiative precursor (the prompt GRB) and a relativistic front of free neutrons. The radiative precursor preaccelerates the medium and loads it with e pairs. This provides a new explanation for the early optical flashes in GRBs. The front o...

Residual 60Co activity in five steel samples induced by neutrons from the Nagasaki atomic bomb has been measured within about 1000 m from the hypocenter. The chemical separation of cobalt and nickel from steel samples was performed, and cobalt-enriched samples were prepared for all samples. Gamma-ray measurements were carried out with a low-background well-type germanium detector. The gamma-ray...