Development of a high-efficiency pulsed slow positron beam for measurements with orthopositronium in vacuum

Abstract

We have developed a high-efficiency pulsed slow positron beam for experiments with orthopositronium in vacuum. The new pulsing scheme is based on a double-gap coaxial buncher powered by an RF pulse of appropriate shape. The modulation of the positron velocity in the two gaps is used to adjust their time-of-flight to a target. This pulsing scheme allows to minimize non-linear aberrations in the bunching process and to efficiently compress positron pulses with an initial pulse duration ranging from 300 to 50 ns into bunches of 2.3 to 0.4 ns width, respectively, with a repetition period of 1 mks. The compression ratio achieved is ~100, which is a factor 5 better than has been previously obtained with slow positron beams based on a single buncher. Requirements on the degree, to which the moderated positrons should be mono-energetic and on the precision of the waveform generation are presented. Possible applications of the new pulsed positron beam for measurements of thin films are discussed.

16 pages, 11 figures

References in corpus (4)

• Can the mirror world explain the ortho-positronium lifetime puzzle?
• An apparatus to search for mirror dark matter via the invisible decay of orthopositronium in vacuum
• Positronium as a probe for new physics beyond the standard model
• Extra dimensions and invisible decay of orthopositronium

Cited by in corpus (7)

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• Observation of positronium annihilation in the 2S state: towards a new measurement of the 1S-2S transition frequency
• Positronium Portal into Hidden Sector: A new Experiment to Search for Mirror Dark Matter
• Producing long-lived $2^3\text{S}$ Ps via $3^3\text{P}$ laser excitation in magnetic and electric fields
• First search for invisible decays of ortho-positronium confined in a vacuum cavity
• A new approach for the ortho-positronium lifetime determination in a vacuum cavity