Related papers: Pulsed UCN production using a Doppler shifter at J…
The dynamical structure factor of solid $^{15}$N$_{2}$ in the $\alpha$ phase ($T<35$K) is measured at the IN4 time-of-flight spectrometer at the Institut Laue Langevin, and the potential performance of this substance as a UCN converter is…
It is demonstrated that the time evolution of the electron-nuclear polarization transfer process during pulsed dynamic nuclear polarization (DNP) can be reversed on a microsecond timescale, leading to the observation of DNP echoes. The DNP…
Solid deuterium (sD_2) is used as an efficient converter to produce ultracold neutrons (UCN). It is known that the sD_2 must be sufficiently cold, of high purity and mostly in its ortho-state in order to guarantee long lifetimes of UCN in…
A proposed Very Cold Neutron Source (VCNS) would operate with 4 ms long pulses at 5 Hz and 1 GeV. The energy per pulse would be 300 kJ, much higher than the Spallation Neutron Source (33 kJ/pulse) or the present IPNS (0.3 kJ/pulse), and the…
Although ultraviolet (UV) light is important in many areas of science and technology, there are very few if any lasers capable of delivering wavelength-tunable ultrashort UV pulses at MHz repetition rates. Here we report the generation of…
A neutron decays into a proton, an electron, and an anti-neutrino through the beta-decay process. The decay lifetime ($\sim$880 s) is an important parameter in the weak interaction. For example, the neutron lifetime is a parameter used to…
The Japan Proton Accelerator Research Complex (J-PARC) currently delivers a 1 MW, 3 GeV proton beam to the Materials and Life Science Experimental Facility (MLF). Power is expected to increase to 1.3 MW, driven by the needs of…
The most accurate neutron lifetime measurements now use the material or magnetic traps of ultracold neutrons (UCN). The precision of these experiments is determined by the accuracy of estimating the neutron loss rate. In material UCN traps…
Dynamical nuclear polarisation (DNP) is an important technique that uses polarisation transfer from electron to nuclear spins to achieve nuclear hyperpolarisation. As the electron spin of the nitrogen vacancy (NV) centres in diamond can be…
Present probes do not exclude that the neutron ($n$) oscillation into mirror neutron ($n'$), a sterile state exactly degenerate in mass with the neutron, can be a very fast process, in fact faster than the neutron decay itself. This process…
We report the first wideband observations of pulsars C, D and J in the globular cluster 47Tucanae (NGC 104) using the Ultra-Wideband Low (UWL) receiver system recently installed on the Parkes 64 m radio telescope. The wide frequency range…
Modeling the motion of ultracold neutrons (UCNs) is crucial for assessing their losses, accurately measuring their lifetime, and describing other experiments. In material traps, it is necessary to account not only for specular but also for…
A concept to search for a neutron electric dipole moment (nEDM) is presented, which employs a pulsed neutron beam instead of the nowadays established use of storable ultracold neutrons (UCN). The technique takes advantage of the high peak…
We investigate the possibility of ultracold neutron (UCN) storage in quantum states defined by the combined potentials of the Earth's gravity and the neutron optical repulsion by a horizontal surface of liquid helium. We analyse the…
We propose a new method to form very cold neutron (VCN) beams collimated and monochromatic without usual losses of flux by three or more orders in magnitude due to narrow line cutting from energy and angular spectra. To this purpose…
Since two decades, laser-driven neutron emissions are studied as they represent a complementary source to conventional neutron sources, with further more different characteristics (i.e. shorter bunch duration and higher number of neutrons…
It was pointed out recently that oscillation of the neutron $n$ into mirror neutron $n'$, a sterile twin of the neutron with exactly the same mass, could be a very fast process with the the baryon number violation, even faster than the…
The accelerating expansion of the Universe, attributed to dark energy, has spurred interest in theories involving scalar fields such as chameleon field theories. These fields, which couple to matter with density-dependent effective mass,…
Position-sensitive detection of ultracold neutrons (UCNs) is demonstrated using an imaging charge-coupled device (CCD) camera. A spatial resolution less than 15 $\mu$m has been achieved, which is equivalent to an UCN energy resolution below…
A neutron source is proposed. It is based on a proton accelerator with the energy Ep = 1.2 GeV, current Ip = 0.7A, pulse duration T = 3 mcsec, repetition rate F = 60 Hz, and accelerator length L = 30 m. Protons are accelerated by the field…