相关论文: Entwicklung eines Gasmoderators f\"ur Positronen

Positron moderation is a key part of the production of slow positrons. This paper examines G4beamline simulations of various moderator designs and the addition of a radiofrequency cavity to increase the efficiency of the moderator. A setup…

A new concept is proposed for accelerating positrons in a nonlinear plasma wakefield accelerator. By loading the wakefield (back of the plasma bubble) with a short electron bunch, an extended area of excessive plasma electron accumulation…

Plasma-based positron acceleration is still an open question, as the most efficient regimes for electron acceleration (quasi-linear and blowout) are not directly applicable to positrons. Nevertheless, positron acceleration is a stepping…

The rapid progress that plasma wakefield accelerators are experiencing is now posing the question as to whether they could be included in the design of the next generation of high-energy electron-positron colliders. However, the typical…

Monte Carlo simulations of slow positron production via energetic electron interaction with a solid target have been performed. The aim of the simulations was to determine the expected slow positron beam intensity from a low energy, high…

A novel approach for positron injection and acceleration in laser driven plasma wakefield is proposed. A theoretical model is developed and confirmed through PIC simulation. One ring-shaped beam and one co-axially propagating Gaussian beam…

Slow positrons are increasingly important to the study of material surfaces. For these kinds of studies, the positrons must have low emittance and relatively high brightness. Unfortunately, fast positron sources like radioactive capsules or…

We present a monoenergetic positron beam specifically tailored to the needs of (near-) surface positron annihilation spectroscopy. The Setup for LOw-energy Positron Experiments (SLOPE) comprises a high-activity 22Na source, a tungsten…

We report the realisation of a cyclotron trap assisted positron tungsten moderator for the conversion of positrons with a broad keV- few MeV energy spectrum to a mono-energetic eV beam with an efficiency of 1.8(2)% defined as the ratio of…

Positron cooling via inelastic collisions in CF$_4$ and N$_2$ gases is simulated, including positron-positron interactions. Owing to the molecular symmetries, cooling is assumed to be chiefly due to energy loss via vibrational (rotational)…

We present the results of theoretical and numerical studies on the source of slow positrons for NSC KIPT. The positrons are intended to generate with the electrons of 9, 40 or 90 MeV available at the KIPT electron linacs. The yield of…

For the GBAR (Gravitational Behaviour of Antihydrogen at Rest) experiment at CERN's Antiproton Decelerator (AD) facility we have constructed a source of slow positrons, which uses a low-energy electron linear accelerator (linac). The driver…

Plasma acceleration is considered a prospective technology for building a compact multi-TeV electron-positron collider in the future. The challenge of this endeavor is greater for positrons than for the electrons because usually the…

Gas stopping is becoming the method of choice for converting beams of rare isotopes obtained via projectile fragmentation and in-flight separation into low-energy beams. These beams allow ISOL-type experiments, such as mass measurements…

The construction and first operation of the slow positron beam built at the Hebrew University is reported here. The beam follows a traditional design, using a 22Na source, a Tungsten moderator, and a target cell equipped with a load-lock…

Plasma accelerators sustain extreme field gradients, and potentially enable future compact linear colliders. Although tremendous progress has been achieved in accelerating electron beams in a plasma accelerator, positron acceleration with…

Accelerating particles to high energies in plasma wakefields is considered to be a promising technique with good energy efficiency and high gradient. While important progress has been made in plasma-based electron acceleration, positron…

We report the instrumentation of a new positron diffractometer that is connected to the high-intensity positron source NEPOMUC. Crucial elements for the adaption of the positron beam are presented, which include the magnetic field…

This chapter reviews the following items: 1. Energy deposition and track structure of fast positrons: ionization slowing down, number of ion-electron pairs, typical sizes, thermalization, electrostatic interaction between e+ and its blob,…

Plasma-based acceleration of positrons attracts extensive interests due to the ultrahigh accelerating gradient and ultrashort duration, while generating wakefield positron beam by the inherent injection is still a great challenge. Here, we…