Numerous X-ray bursts show strong oscillations in their flux at several hundred Hz as revealed by RXTE. Analyzing one such oscillation from the X-ray binary Aql X-1, I find that low energy photons (3.5–5.7 keV) lag high energy photons (> 5.7 keV) by approximately 1 radian. The oscillations are thought to be produced by hot spots on the spinning neutron star. The lags can then be explained by a ...

The detectability of a possible “high” energy (> 100GeV) component of Gamma-Ray Bursts (GRBs) using AMANDA/ICECUBE type large area muon detectors is examined within the context of a specific model of such high energy gamma ray production within GRBs, namely, the proton-synchrotron model, which requires protons to be accelerated to ultrahigh energies >∼ 1020 eV within GRBs. In this model, the hi...

We discuss the high enegry afterglow emission (including high energy photons, neutrinos and cosmic rays) following the 2004 December 27 Giant Flare from SGR 1806-20. If the initial outflow is relativistic with a bulk Lorentz factor Γ0 ∼ tens, the high-energy tail of the synchrotron emission from electrons in the forward shock region gives rise to a prominent sub-GeV emission, if the electron sp...

Introduction: Due to nuclear interactions between the tissues and high-energy protons, the particles, including neutrons, positrons, and photons arise during proton therapy. This study aimed at investigating the dose distribution of proton and secondary particles, such as positrons, neutrons, and photons using the Monte Carlo method. Material and Methods:<...

In optical materials energy is usually extracted only from the lowest excited state, resulting in fundamental energy-efficiency limits such as the Shockley-Queisser limit for single-junction solar cells. Photon-cutting materials provide a way around such limits by absorbing high-energy photons and 'cutting' them into multiple low-energy excitations that can subsequently be extracted. The occurr...

Objective(s): The energy resolution of a cadmium-zinc-telluride (CZT) solid-state semiconductor detector is about 5%, and is superior to the resolution of the conventional Anger type detector which is 10%. Also, the window width of the high-energy part and of the low-energy part of a photo peak window can be changed separately. In this study, we used a semiconductor detector and examined the ef...

Current and future high energy physics particle colliders are capable to provide instantaneous luminosities of 1034 cm-2s-1 and above. The high center of mass energy, the large number of simultaneous collision of beam particles in the experiments and the very high repetition rates of the collision events pose huge challenges. They result in extremely high particle fluxes, causing very high occu...

today, due to qualitative growth and scientific advances, energy, especially electricity is increasingly needed by human society. one of the almost endless and pure energy which have been paid attention over the years is the solar energy. solar cells directly convert solar energy into electrical energy and are one of the main blocks of photovoltaic systems. significant improvement has been made...

One of the last frontiers of the gamma-ray sky is that characterized by the distribution of TeV photons. These photons can be detected relatively easily with ground-based detectors (constituting a TeV “window” in the atmosphere); thus the detection of TeV gamma-ray sources did not have to await the availability of space platforms. In practice although the technology was available at an early da...

It is possible using current high-intensity laser facilities to reach the quantum radiation reaction regime for energetic electrons. An experiment using a wakefield accelerator to drive GeV electrons into a counterpropagating laser pulse would demonstrate the increase in the yield of high-energy photons caused by the stochastic nature of quantum synchrotron emission: we show that a beam of 10(9...