Thermal desorption of cold positronium from oxygen-treated Al(111) surfaces

Ap, Mills; Ed, Shaw; Leventhal, M.; Rj, Chichester; Dm, Zuckerman

doi:10.1103/physrevb.44.5791

Cited by 31 publications

(11 citation statements)

References 61 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Even if it were performed in the most optimal way possible, the overall efficiency is intrinsically limited by the ground state lifetime, and without trapping them Ps atoms will be moving away from their source by many cm in this time. It may be that producing a cold distribution (e.g., by oxygen assisted thermal desorption from a metal surface [235]) and then velocity-selecting the coldest part will always be competitive will laser cooling; certainly this is considerably easier to implement. Possibly transitions that do not involve the ground state can be used, but only if the atoms are not spreading out to much, which would essentially mean they were already cold.…”

Section: Discussionmentioning

confidence: 99%

“…This was demonstrated with Al(1 1 1) at ≈100 K by applying a layer of O 2 [235]. Unfortunately the O 2 layer has to be kept in pristine condition, and needs careful perpetration and extensive maintenance, especially when used with UV lasers [108].…”

Section: Ps Productionmentioning

confidence: 99%

“…The possibility of using colder Ps made the idea of using a CW laser to perform the experiments much more attractive [108]. Although preliminary tests suggested that the thermal Ps emitted from oxygen covered Al cooled to 235 K [235] would be compatible with a CW experiment, it turned out that the surfaces were quite sensitive to laser light and could not be used for long-term experimentation; ultimately a hot (576 K) Al target was used in the measurements [107].…”

Section: Doppler-free Two-photon Transitionsmentioning

confidence: 99%

See 2 more Smart Citations

Experimental progress in positronium laser physics

2018

View full text Add to dashboard Cite

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.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Ps Productionmentioning

confidence: 99%

Section: Doppler-free Two-photon Transitionsmentioning

confidence: 99%

See 1 more Smart Citation

Experimental progress in positronium laser physics

2018

View full text Add to dashboard Cite

show abstract

“…Because of their low mass (2m e ) thermal Ps atoms at 300 K have speeds of ∼7 × 10 4 ms −1 , which is orders of magnitude faster than one can obtain from, for example, a supersonic gas expansion (e.g., [35]) or a buffer gas source (e.g., [36]). Some techniques have been developed to produce colder Ps atoms [37][38][39], but they are not efficient and/or require unstable targets. Alternative methods under investigation include using cryogenic mesoporous silica films with larger pores [40,41], or Ps production via delocalized Bloch states in metal-organic-framework materials [20].…”

mentioning

confidence: 99%

Electrostatically Guided Rydberg Positronium

Deller

Alonso

et al. 2016

Phys. Rev. Lett.

View full text Add to dashboard Cite

We report experiments in which positronium (Ps) atoms were guided using inhomogeneous electric fields. Ps atoms in Rydberg-Stark states with principal quantum number n=10 and electric dipole moments up to 610 D were prepared via two-color two-photon optical excitation in the presence of a 670 V cm^{-1} electric field. The Ps atoms were created at the entrance of a 0.4 m long electrostatic quadrupole guide, and were detected at the end of the guide via annihilation gamma radiation. When the lasers were tuned to excite low-field-seeking Stark states, a fivefold increase in the number of atoms reaching the end of the guide was observed, whereas no signal was detected when high-field-seeking states were produced. The data are consistent with the calculated geometrical guide acceptance.

show abstract

“…For all the mentioned applications, it would be of great help to have a high spatial-resolution position sensitive detector for slow Ps. Indeed, it would allow monitoring the Ps emission from + e /Ps converters [12][13][14][15][16][17], it would be a quick diagnostic tool for Ps laser excitation experiments, it would permit the fast characterization in terms of transport and focus of a long-lived Ps beam [18][19][20] and, in the future, it could be employed in force-sensitive inertial experiments with Ps as test particle to detect and measure the fringe pattern generated by a deflectometer/interferometer device [11].…”

Section: Introductionmentioning

confidence: 99%

A ∼100 μm-resolution position-sensitive detector for slow positronium

Amsler

Antonello

Belov

et al. 2019

Nuclear Instruments and Methods in Physics Research Section B:

View full text Add to dashboard Cite

In this work we describe a high-resolution position-sensitive detector for positronium. The detection scheme is based on the photoionization of positronium in a magnetic field and the imaging of the freed positrons with a Microchannel Plate assembly. A spatial resolution of ± (88 5) μm on the position of the ionized positronium -in the plane perpendicular to a 1.0 T magnetic field-is obtained. The possibility to apply the detection scheme for monitoring the emission into vacuum of positronium from positron/positronium converters, imaging posihttps://doi.

show abstract

Thermal desorption of cold positronium from oxygen-treated Al(111) surfaces

Cited by 31 publications

References 61 publications

Experimental progress in positronium laser physics

Experimental progress in positronium laser physics

Electrostatically Guided Rydberg Positronium

A ∼100 μm-resolution position-sensitive detector for slow positronium

Contact Info

Product

Resources

About

Thermal desorption of cold positronium from oxygen-treated Al(111) surfaces

Cited by 31 publications

References 61 publications

Experimental progress in positronium laser physics

Experimental progress in positronium laser physics

Electrostatically Guided Rydberg Positronium

A ∼100 μm-resolution position-sensitive detector for slow positronium

Contact Info

Product

Resources

About

A ∼100 μm-resolution position-sensitive detector for slow positronium