Search results for "Electron attachment"

showing 2 items of 2 documents

A purity monitoring system for liquid argon calorimeters

2005

Abstract For liquid argon calorimeters electronegative impurities dissolved in the medium degrade the detector response and deteriorate the energy resolution, especially at high energies. A concept for a purity monitoring system for liquid argon calorimeters has been developed and is presented here. Special combined monitors of 241 Am- and 207 Bi-cells are used to monitor the concentration of impurities. The working principle as well as results from test measurements are discussed.

PhysicsNuclear and High Energy PhysicsResolution (mass spectrometry)Physics::Instrumentation and DetectorsImpurityDetectorElectron attachmentAnalytical chemistryLiquid argonHigh Energy Physics::ExperimentMonitoring systemPhysics::Chemical PhysicsInstrumentationNuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
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Radiofrequency and 2.45 GHz electron cyclotron resonance H− volume production ion sources

2016

The volume production of negative hydrogen ions (H-) in plasma ion sources is based on dissociative electron attachment (DEA)to rovibrationally excited hydrogen molecules(H2), which is a two-step process requiring both, hot electrons for ionization, and vibrational excitation of the H2 and cold electrons for the H- formation through DEA. Traditionally H- ion sources relying on the volume production have been tandem-type arc discharge sources equipped with biased filament cathodes sustaining the plasma by thermionic electron emission and with a magnetic filter separating the main discharge from the H- formation volume. The main motivation to develop ion sources based on radiofrequency (RF) o…

radiofrequency plasma dischargedissociative electron attachmentnegative ion sourceelectron cyclotron resonance
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