Invariance in Transverse Momentum of Photons in Double-slit Experiment

One of the intriguing mystery in modern physics is the quantum interference phenomena, which the behaviour of photons in double-slit experiment is still ambiguous. Instead of relying on the naive probabilistic point of view, Bohmian mechanics provides the ground base for interpreting quantum system in a deterministic way closely related to classical mechanics such as it constructs the photon trajectory for the double-slit set up. The appearance on the bending in the constructed photon trajectory seem to contravene the notable law of conservation of momentum. Here, we report on conservation of the transverse momentum of photon trajectories based on numerical solution of Bohmian mechanics in double-slit set up for single photon, pair of photons and ensemble of photons until interference pattern is produced. It is shown that the total transverse momentum in the system of Bohmian mechanics is invariance due to the non-local action of quantum potential

Supercapacitor performance gains from structural modification of carbon electrodes using gamma radiations

The performance of supercapacitors (SC) strongly depends on how their activated carbon (AC) electrodes were synthesized from precursor materials and pretreatments applied to them. This study investigates the effect of direct and filtered gamma radiations applied as pretreatments to the AC. The exposure doses used were from 0.1 kGy to 6 kGy. The high gamma-energy and high dose of the pretreatment broke the randomly orientated graphitic crystal lattices inside AC particles and disturbed the existing functional group populations. The filtered radiation pretreatment at 1 kGy, which contains a higher composition of secondary electrons than direct radiation pretreatment, yields AC with the best overall SC performance. The SC cell made from 1 kGy filtered radiation pretreatment AC showed higher specific capacitance 73.1 % (218.58 F g-1), specific energy 73.54 % (10.96 W h kg-1) and specific power of 8.36 % (155.67 W kg-1) compared to the sample without any radiation pretreatment. This study explicitly shows the benefit of secondary electrons in the radiation field, which produce decisively defect sites on the AC lattices for gains in SC performance

Optimising the packaging of semiconductor detectors to improve their energy response to gamma and neutron radiation for radiation protection: a GEANT4 Monte Carlo study

There are many types of semiconductor detectors used in radiation detection and dosimetry. A common problem of these detectors under a wide energy spectrum is that their response in a radiation field depends on energy. In radiation protection-applications, gamma and neutron are the most common primary radiation. Other forms of radiation, such as hadronic particles, are important in space applications, but are not included in the scope of this study because they deserve a separate examination. This study mainly focuses on the development of semiconductor dosimeters for mixed gamma-neutron, with an improved energy response achieved by an innovative design and packaging that can adjust the energy response of the detector for each application. Two detectors – were the metal-oxide-semiconductor field-effect transistor (MOSFET) for gamma dosimetry and the pixelated silicon diode detector, Medipix2 [1] for fast neutron dosimetry – were modelled using a Monte Carlo simulation developed in the GEometry ANd Tracking (GEANT4) application toolkit to improve their energy response. Since the MOSFET was introduced to the field of radiation detection, its packaging has undergone many evolutions to satisfy its intended working conditions. This study focuses on the optimisation of MOSFET packaging to adjust its energy response for personnel dosimeter applications. The aim of this optimisation was to reduce its tendency to over-respond at photon energy less than 100 keV. Medipix2 was first developed as a tracker of high-energy charged particles in HEP applications; it subsequently found a use as an X-ray imaging detector. In later developments Medipix2 demonstrated its ability in neutron imaging and detection [2], thereby showing its potential as a neutron dosimeter. This research proposed and developed a structured hydrogen-rich neutron converter coupled with Medipix2 to achieve an independent energy response. The converter was designed to allow Medipix2 to measure the ambient dose equivalent of neutrons [3]. The GEANT4 simulation results were then compared to the preliminary experimental results on fastneutron sources. These promising results will help pave the way for future development of a novel fast-neutron detector