Forward Diffracted Parametric X Radiation From a Thick Tungsten Single Crystal at 855 MeV Electron Energy

Gamma Radiation Spectra of 1200 MeV Electrons in Thick Beryllium, Silicon, and Tungsten Single Crystals

Gamma radiation spectra of 1200 MeV electrons in the single crystals of the beryllium 1.2 mm thick, silicon 1.5 mm and 15.0 mm thick and tungsten 1.18 mm thick along of the crystallographic axes were measured. Also spectral-angular distributions of gamma radiation in the silicon single crystals 1.5 mm thick along of the crystallographic axes <100>, <110> and <111> were measured. On the basis of these measurements the radiation spectra for the different solid angles up to 6.97*10-6 sr were obtained. Gamma radiation spectra of the electrons with energy 1200, 600 and 300 MeV in the Si single crys…

Creation of high energy/intensity bremsstrahlung by a multitarget and focusing of the scattered electrons by small-angle backscatter at a cone wall and a magnetic field II - Enhancement of the outcome of linear accelerators in radiotherapy

The yield of bremsstrahlung from collisions of fast electrons (energy at least 6 MeV) with a Tungsten target can be significantly improved by exploitation of Tungsten wall scatter in a multi-layered target. A simplified version of a previously developed principle is also able to focus small angle scattered electrons by a Tungsten wall. It is necessary that the thickness of each Tungsten layer does not exceed 0.04 mm - a thickness of 0.03 mm is suitable for accelerators in medical physics. Further focusing of electrons results from suitable magnetic fields with field strength between 0.5 Tesla …

Advantages of axially aligned crystals used in positron production at future linear colliders

The characteristics of the electron-photon showers initiated by 2 to 10 GeV electrons aligned along the <111>-axis of tungsten crystals are compared with those for the amorphous tungsten . In this energy range, as known, the positron yield at the optimal target thicknesses is larger in a crystal case only by several percent. However, the amount of the energy deposition in a crystal turns out to be considerably (by 20 - 50 %) lower than in an amorphous target providing the same positron yield, while the peak energy-deposition density is approximately of the same magnitude in the both cases.

CEBAF 正电子生产用高功率靶设计的评估

Evaluation of a High-Power Target Design for Positron Production at CEBAF

本文评估了 CEBAF 极化正电子源中 4 mm 厚旋转钨靶在水冷铜盘上的高功率设计，结合 ANSYS 热力学分析与 FLUKA 辐射损伤评估验证其可行性。

Design study for a 500 MeV positron beam at the Mainz Microtron MAMI

A design study has been performed for a positron beam with an energy of 500 MeV to be realized at the applied physics area of the Mainz Microtron MAMI. Positrons will be created after pair conversion of bremsstrahlung, produced by the 855 MeV electron beam af MAMI in a tungsten converter target. From the two conceivable geometries (i) pair conversion in the bremsstrahlung converter target itself, and (ii) bremsstrahlung pair conversion in a separated lead foil, the former was considered in detail. Positrons will be energy selected within an outside open electron beam-line bending magnet, and b…

极化与非极化正电子产生的特性与优化

Characterization and optimization of polarized and unpolarized positron production

本文研究了电子诱导正电子产生的多参数优化问题，针对120~MeV和1000~MeV电子束动能及钨靶，揭示了最佳靶厚度与收集系统角接受度间的强相关性，以及极化与非极化运行模式间的显著差异。