Precision Measurement of the Position-space Wave Functions of Gravitationally Bound Ultracold Neutrons

Gravity is the most familiar force at our natural length scale. However, it is still exotic from the view point of particle physics. The first experimental study of quantum effects under gravity was performed using a cold neutron beam in 1975. Following this, an investigation of gravitationally bound quantum states using ultracold neutrons was started in 2002. This quantum bound system is now well understood, and one can use it as a tunable tool to probe gravity. In this paper, we review a recent measurement of position-space wave functions of such gravitationally bound states, and discuss issues related to this analysis, such as neutron loss models in a thin neutron guide, the formulation of phase space quantum mechanics, and UCN position sensitive detectors. The quantum modulation of neutron bound states measured in this experiment shows good agreement with the prediction from quantum mechanics.Comment: 13 pages, 5 figure

Angular and Abundance Distribution of High-energy Gamma Rays and Neutrons Simulated by GEANT4 Code for Solar Flares

In the solar flare observed on June 3, 2012, high energy gamma-rays and neutrons were observed. The event includes a remarkable feature of a high neutron/gamma-ratio in the secondary particles. We have examined whether this high n/$\gamma$-ratio can be explained by simulation. As a result of simulations using the GEANT4 program, the high n/$\gamma$-ratio may be reproduced for the case that helium and other heavy ions were dominantly accelerated in the flare.Comment: submitted to the Proceeding of The 20th International Symposium on Very High Energy Cosmic Ray Interaction (ISVHECRI 2018, Nagoya, Japan), Europian Physics Journa

Discrete subgroups of PU(2,1) with screw parabolic elements

We give a version of Shimizu's lemma for groups of complex hyperbolic isometries one of whose generators is a parabolic screw motion. Suppose that G is a discrete group containing a parabolic screw motion A and let B be any element of G not fixing the fixed point of A. Our result gives a bound on the radius of the isometric spheres of B and B−1 in terms of the translation lengths of A at their centres. We use this result to give a sub-horospherical region precisely invariant under the stabiliser of the fixed point of A in G

Monolithic Ge:Ga Detector Development for SAFARI

We describe the current status and the prospect for the development of monolithic Ge:Ga array detector for SAFARI. Our goal is to develop a 64x64 array for the 45 -- 110 um band, on the basis of existing technologies to make 3x20 monolithic arrays for the AKARI satellite. For the AKARI detector we have achieved a responsivity of 10 A/W and a read-out noise limited NEP (noise equivalent power) of 10^-17 W/rHz. We plan to develop the detector for SAFARI with technical improvements; significantly reduced read-out noise with newly developed cold read-out electronics, mitigated spectral fringes as well as optical cross-talks with a multi-layer antireflection coat. Since most of the elemental technologies to fabricate the detector are flight-proven, high technical readiness levels (TRLs) should be achieved for fabricating the detector with the above mentioned technical demonstrations. We demonstrate some of these elemental technologies showing results of measurements for test coatings and prototype arrays.Comment: To appear in Proc. Workshop "The Space Infrared Telescope for Cosmology & Astrophysics: Revealing the Origins of Planets and Galaxies". Eds. A.M. Heras, B. Swinyard, K. Isaak, and J.R. Goicoeche

Summary of Payload Integration Plan (PIP) for Starlab-1 flight experiment, enclosure 3

The objectives of the Autogenic Feedback Training (AFT) are to: determine if preflight AFT is an effective treatment for space adaptation syndrome (SAS); determine if preflight improvements in motion sickness tolerance can be used to predict crewmembers' success in controlling symptoms in flight; and identify differences and similarities between the physiological data from preflight motion sickness tests and data collected during symptom episodes in space. The goal is to test the AFT on 8 trained and 8 control subjects. At present 2 trained and 2 contol subjects were tested. The testing will continue until the experimental goal of testing 16 individual is reached

Josephson junction in cobalt-doped BaFe2As2 epitaxial thin films on (La, Sr)(Al, Ta)O3 bicrystal substrates

Josephson junctions were fabricated in epitaxial films of cobalt-doped BaFe2As2 on [001]-tilt (La,Sr)(Al,Ta)O3 bicrystal substrates. 10m-wide microbridges spanning a 30-degrees-tilted bicrystal grain boundary (BGB bridge) exhibited resistively-shunted-junction (RSJ)-like current-voltage characteristics up to 17 K, and the critical current was suppressed remarkably by a magnetic field. Microbridges without a BGB did not show the RSJ-like behavior, and their critical current densities were 20 times larger than those of BGB bridges, confirming BGB bridges display a Josephson effect originating from weakly-linked BGB