Plasma Induced Defects in GaAs Probed by a Monoenergetic Positron Beam
نویسندگان
چکیده
منابع مشابه
Electron beam-induced absorption modulation imaging of strained In0.2Ga0.8As/GaAs multiple quantum wells
We have examined the effects of electron-hole plasma generation on excitonic absorption phenomena in nipi-doped In&&,sAs/GaAs multiple quantum wells (MQWs) using a novel technique called electron beam-induced absorption modulation imaging. The electron-hole plasma is generated by a high-energy electron beam in a scanning electron microscope and is used as a probe to study the MQW absorption mod...
متن کاملPositron Facilities in Europe
Positron annihilation is a well established method in solid state physics and material science. The positron being a very sensitive probe, can give very precise information on the momentum distribution of electrons in metals and alloys as well as on lattice defects in crystals. Starting with the energy distribution of positrons from a radioactive decay, the current development is directed more ...
متن کاملImproved source and transport of monoenergetic MeV positrons
A new monoenergetic MeV positron beam source was designed and constructed at the Lawrence Livermore National Laboratory (LLNL) positron facility. The positron source provides a low emittance beam with high energy resolution for channeling, scattering, and in̄ight annihilation experiments. New beam optics for extracting slow positrons from a moderator mounted in a Pelletron electrostatic accelera...
متن کاملLaser Energy Conversion to Solitons and Monoenergetic Protons in Near-critical Hydrogen Plasma*
Recent theoretical and experimental studies point to better efficiency of laser-driven ion acceleration when approaching the critical plasma density regime. Simultaneously, this is the condition for observing solitons: "bubble"-like quasi-stationary plasma formations with laser radiation trapped inside. Exploring this regime with ultra-intense solid state lasers is problematic due to the lack o...
متن کاملPlasma-wakefield acceleration of an intense positron beam.
Plasma wakefields are both excited and probed by propagating an intense 28.5 GeV positron beam through a 1.4 m long lithium plasma. The main body of the beam loses energy in exciting this wakefield while positrons in the back of the same beam can be accelerated by the same wakefield as it changes sign. The scaling of energy loss with plasma density as well as the energy gain seen at the highest...
متن کامل