Quasidivergency-free extraction of a slow positron beam from high magnetic fields

Gerola, D.; Waeber, W.B.; Shi, M.; Wang, S. J.

doi:10.1063/1.1145443

Cited by 17 publications

(13 citation statements)

References 10 publications

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“…However, such pulsed fields introduce numerous experimental complications, and the fields that can be generated are not easily scalable. A more fruitful approach may be to extract the positron plasma into a field-free region [92,329,681] and increase the areal density by remoderation [682]. In this way one could expect to improve the beam brightness, losing approximately a factor of 10 in the number of positrons, but gaining a factor of 100 in the density [683].…”

Section: Bose-einstein Condensationmentioning

confidence: 99%

Experimental progress in positronium laser physics

2018

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Abstract. The field of experimental positronium physics has advanced significantly in the last few decades, with new areas of research driven by the development of techniques for trapping and manipulating positrons using Surko-type buffer gas traps. Large numbers of positrons (typically ≥10 6 ) accumulated in such a device may be ejected all at once, so as to generate an intense pulse. Standard bunching techniques can produce pulses with ns (mm) temporal (spatial) beam profiles. These pulses can be converted into a dilute Ps gas in vacuum with densities on the order of 10 7 cm −3 which can be probed by standard ns pulsed laser systems. This allows for the efficient production of excited Ps states, including long-lived Rydberg states, which in turn facilitates numerous experimental programs, such as precision optical and microwave spectroscopy of Ps, the application of Stark deceleration methods to guide, decelerate and focus Rydberg Ps beams, and studies of the interactions of such beams with other atomic and molecular species. These methods are also applicable to antihydrogen production and spectroscopic studies of energy levels and resonances in positronium ions and molecules. A summary of recent progress in this area will be given, with the objective of providing an overview of the field as it currently exists, and a brief discussion of some future directions.

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Section: Bose-einstein Condensationmentioning

confidence: 99%

Experimental progress in positronium laser physics

2018

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“…Nevertheless, a number of experiments that have succeeded in taking positrons (or electrons) from a high magnetic field into a field-free region Akahane (1994); Gerola et al (1995); Greaves and Surko (2002a); Shi et al (1995). Figure 33 shows the experimental arrangement of a recent experiment in which electron plasma was tailored in a PM trap in a 5 T field, then a beam was extracted, transported to a field-free region, and then focused with an electrostatic Einzel lens .…”

Section: E Electrostatic Beamsmentioning

confidence: 99%

Plasma and trap-based techniques for science with positrons

Danielson¹,

Dubin²,

Greaves³

et al. 2015

Rev. Mod. Phys.

228

222

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In recent years, there has been a wealth of new science involving low-energy antimatter (i.e., positrons and antiprotons) at energies ranging from 10 2 to less than 10 −3 eV. Much of this progress has been driven by the development of new plasma-based techniques to accumulate, manipulate and deliver antiparticles for specific applications. This article focuses on the advances made in this area using positrons. However many of the resulting techniques are relevant to antiprotons as well. An overview is presented of relevant theory of single-component plasmas in electromagnetic traps. Methods are described to produce intense sources of positrons and to efficiently slow the typically energetic particles thus produced. Techniques are described to trap positrons efficiently and to cool and compress the resulting positron gases and plasmas. Finally, the procedures developed to deliver tailored pulses and beams (e.g., in intense, short bursts, or as quasi-monoenergetic continuous beams) for specific applications are reviewed. The status of development in specific application areas is also reviewed. One example is the formation of antihydrogen atoms for fundamental physics [e.g., tests of invariance under charge conjugation, parity inversion and time reversal (the CPT theorem), and studies of the interaction of gravity with antimatter]. Other applications discussed include atomic and materials physics studies and study of the electron-positron many-body system, including both classical electron-positron plasmas and the complementary quantum system in the form of Bose-condensed gases of positronium atoms. Areas of future promise are also discussed. The review concludes with a brief summary and a list of outstanding challenges.

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“…The magnetic spider 34 is designed to help circumvent this limitation. Similar designs have been used previously, 28,30,31 but only at larger transport energies than those employed here. The impulses to the particles are dominated by the change in the magnetic vector potential term.…”

Section: B Non-adiabatic Beam Extractionmentioning

confidence: 96%

“…. 26 Positrons (or electrons) have been successfully extracted from a high magnetic field into a field-free region in previous experiments, [27][28][29][30][31][32] but all relied on first accelerating the particles to kiloelectronvolt energies. More recently, lowenergy ($30 eV) beams from a specially tailored electron plasma in a PM trap, operating at a field of 4.8 T, were transported to a field-free region and then focused with an electrostatic (Einzel) lens.…”

Section: Introductionmentioning

confidence: 99%

Magnetic field extraction of trap-based electron beams using a high-permeability grid

2015

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A method to form high quality electrostatically guided lepton beams is explored. Test electron beams are extracted from tailored plasmas confined in a Penning-Malmberg trap. The particles are then extracted from the confining axial magnetic field by passing them through a high magnetic permeability grid with radial tines (a so-called "magnetic spider"). An Einzel lens is used to focus and analyze the beam properties. Numerical simulations are used to model non-adiabatic effects due to the spider, and the predictions are compared with the experimental results. Improvements in beam quality are discussed relative to the use of a hole in a high permeability shield (i.e., in lieu of the spider), and areas for further improvement are described. V C 2015 AIP Publishing LLC.

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Quasidivergency-free extraction of a slow positron beam from high magnetic fields

Cited by 17 publications

References 10 publications

Experimental progress in positronium laser physics

Experimental progress in positronium laser physics

Plasma and trap-based techniques for science with positrons

Magnetic field extraction of trap-based electron beams using a high-permeability grid

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