Related papers: gamma-ray telescopes using conversions to electron…
We revisit the measurement of the polarization fraction, $P$, and the measurement of the polarization angle of partially linearly-polarized gamma rays using their conversion to $e^+e^-$ pairs in the field of a nucleus. We show that an…
Measurements of circular polarization of $\gamma$-ray emitted from neutron capture reactions provide valuable information for nuclear physics studies. The spin and parity of excited states can be determined by measuring the circular…
The optical theorem is applied to the process of electron-positron pair creation in the superposition of a nuclear Coulomb and a strong laser field. We derive new representations for the total production rate as two-fold integrals, both for…
Field emitted electrons can seriously affect the operation of high-field, high-duty factor electron accelerators. Accelerated field emission can result in high average power beams which can radiation damage beamline components. In addition,…
Low energy protons (< 300 keV) can enter the field of view of X-ray space telescopes, scatter at small incident angles, and deposit energy on the detector, causing intense background flares at the focal plane or in the most extreme cases,…
Accessing the polarization of photon allows to understand the mechanisms behind its emission or scattering, revealing much about a peculiar environment or a probed object. For energy above $\sim$10~MeV, the pair production dominates the…
We report the results of theoretical and numerical analysis of the crystalline undulators planned to be used in the experiments which are the part of the ongoing PECU project [1]. The goal of such an analysis was to define the parameters…
Incorrect choice of measuring geometry and signal discrimination thresholds for the BaF2 PAL spectrometer can lead to a significant distortion in the measured spectrum of positron lifetime. The contribution of the distorted events for…
In this paper, we explore the possibility of measuring the complete polarizations of cosmic photons $\gamma$ and the polarizations of cosmic electrons $e^{-}$ and positrons $e^{+}$. Our innovative Vector Meson Photo-production induced…
The effect of an intense external linear polarized radiation field on the angular distributions and polarization states of the photons emitted during the radiative recombination is investigated. It is predicted, on symmetry grounds, and…
In this paper we analyze the image formation problem for undulator radiation through an optical system, accounting for the influence of the electron beam emittance. On the one hand, image formation with Synchrotron Radiation is governed by…
Event generators are an indispensable tool for the preparation and analysis of particle-physics experiments. In this contribution, physics principles underlying the construction of such computer programs are discussed. Results, within and…
Polarization measurements from relativistic outflows are a valuable tool to probe the geometry of the emission region and the microphysics of the particle distribution. Indeed, the polarization level depends on: (i) the local magnetic field…
Recent measurements of the Geminga and B0656+14 pulsars by the gamma-ray telescope HAWC (along with earlier measurements by Milagro) indicate that these objects generate significant fluxes of very high-energy electrons. In this paper, we…
A photon-positron conversion target of the undulator or laser based polarized positron source is optimized using a modified GEANT-3 program adapted to count the spin transfer. High intensity positron beam with around 0.75 polarisation could…
We extend the angular power density formulae for spontaneous radiation emission from planar undulators to include finite emittance and angular misalignment of the electron beam. Then we calculate and compare power densities estimated from…
The GAMMA-400 gamma-ray telescope is intended to measure the fluxes of gamma rays and cosmic-ray electrons and positrons in the energy range from 100 MeV to several TeV. Such measurements concern with the following scientific goals: search…
The spectrum and polarization produced by particles spiraling in a magnetic field undergo dramatic changes as the emitters transition from nonrelativistic to relativistic energies. However, none of the currently available methods for…
We have constructed a Monte Carlo generator for lowest-order predictions for the processes gamma gamma -> 4f and gamma gamma -> 4f+gamma in the Standard Model and extensions thereof by an effective gamma gamma Higgs coupling as well as…
We present methods to measure the beam polarizations and the luminosity of $\gamma \gamma$ colliders at TeV energy scale. The beam polarizations of a $\gamma \gamma$ collider can easily be monitored by comparing the numbers of events of the…