Optical cooling of atomic hydrogen in a magnetic trap

Setija, I.D.; Werij, H. G. C.; Luiten, O.J.; Reynolds, M.W.; Hijmans, T.W.; Walraven, J.T.M.

doi:10.1103/physrevlett.70.2257

Cited by 145 publications

(81 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The long confinement time makes it plausible to envisage significant cooling even with existing (relatively weak) radiation sources [12,13] by cooling atoms for a long period of time (in the absence of a strong heating mechanism). Adiabatic cooling, possibly in one dimension [ 16 ], could further reduce antihydrogen temperatures to the sub mK range, where gravitational effects will be significant.…”

mentioning

confidence: 99%

“…If sufficiently long confinement of antihydrogen can be achieved, a variety of possibilities will become available for fundamental studies with atomic antimatter. Examples include precision tests of CPT via laser [ 10 ] and microwave [ 11 ] spectroscopy on very few, or even a single trapped anti-atom; and laser [ 12,13,14 ] and adiabatic [ 15,16 ] cooling of antihydrogen to temperatures where gravitational effects become apparent.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Confinement of antihydrogen for 1,000 seconds

et al. 2011

View full text Add to dashboard Cite

Reported trapping times of magnetically confined (matter) atoms range from <1 s in the first, room temperature, traps [ 18 ] to 10 to 30 minutes in cryogenic devices [ 19,20,21,22 ]. However, antimatter atoms can annihilate on background gases. Also, the loading of our trap (i.e., anti-atom production via merging of cold plasmas) is different from that of ordinary atom traps, and the loading dynamics could adversely affect the trapping and orbit dynamics. Mechanisms exist for temporary magnetic trapping of particles (e.g., in quasi-stable trapping orbits [ 23 ], or in excited internal states [ 24 ]); such particles could be short-lived with a trapping time of a few 100 ms. Thus, it is not a priori obvious what trapping time should be expected for antihydrogen. 5In this article, we report the first systematic investigations of the characteristics of trapped antihydrogen. These studies were made possible by significant advances in our trapping techniques subsequent to Ref. [ 17 ]. These developments, including incorporation of evaporative antiproton cooling[ 25 ] into our trapping operation, and optimisation of autoresonant mixing [ 26 ], resulted in up to a factor of five increase in the number of trapped atoms per attempt. A total sample of 309 trapped antihydrogen annihilation events was studied, a large increase from the previously published 38 events.Here we report trapping of antihydrogen for 1000 s, extending earlier results [ 17 ] by nearly four orders of magnitude. Further, we have exploited the temporal and spatial resolution of our detector system to perform a detailed analysis of the antihydrogen release process, from which we infer information on the trapped antihydrogen kinetic energy distribution.The ALPHA antihydrogen trap [ 27,28 ] is comprised of the superposition of a Penning trap for antihydrogen production and a magnetic field configuration that has a three-dimensional minimum in magnitude (Fig. 1). For ground-state antihydrogen, our trap well-depth is 0.54 K (in temperature units).The large discrepancy in the energy scales between the magnetic trap depth (~50 eV), and the characteristic energy scale of the trapped plasmas (a few eV) presents a formidable challenge to trapping neutral anti-atoms. antiprotons at ~100K, with radius 0.4 mm and density 7x10 7 cm -3 is prepared for mixing with positrons.Independently, the positron plasma, accumulated in a Surko-type buffer gas accumulator [ 33 ,34 ], is transferred to the mixing region, and is also radially compressed. The magnetic trap is then energized, 6 and the positron plasma is cooled further via evaporation, resulting in a plasma with a radius of 0.8 mm and containing 1x10 6 positrons at a density of 5x10 7 cm -3 and a temperature of ~40 K. The silicon vertex detector, surrounding the mixing trap in three layers (Fig. 1 a) ]. Knowledge of annihilation positions also provides sensitivity to the antihydrogen energy distribution, as we will show.In Table 1 and Fig. 2, we present the results for a series of measurements, wherein the confinemen...

show abstract

mentioning

confidence: 99%

mentioning

confidence: 99%

Confinement of antihydrogen for 1,000 seconds

et al. 2011

View full text Add to dashboard Cite

show abstract

“…The latter method was used to infer the temperature and density of the trapped HT gas with a time resolution of 0.5 s during evaporative cooling [6]. Furthermore, during optical cooling it allows for occasional excursions to different parts of the spectrum, e.g., for thermometry, while the sample is irradiated at the optimal cooling frequency most of the time [7]. To enable the pulse-to-pulse switching, the cw dye laser light is guided through an arrangement of three Acousto-Optic Modulators (AOMs), which is depicted schematically in Fig.…”

Section: Frequency Tuningmentioning

confidence: 99%

“…6 a spectrum is shown of a sample at a relatively low temperature, which was taken with right-circularly polarized light. The low temperature was obtained by light-induced evaporation [7]. The scan time was 10 s and only the 22p3/2 multiplet was recorded.…”

Section: La= ~Eoc[he++[2+[e+-]2+le-+[2+le--12mentioning

confidence: 99%

See 1 more Smart Citation

VUV spectroscopy of magnetically trapped atomic hydrogen

et al. 1994

Self Cite

View full text Add to dashboard Cite

Disclaimer/Complaints regulationsIf you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: http://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. Download date: 08 May 2018Appl. Phys. B 59, 311-319 (1994) Applied Physics B and Optics Abstract. We discuss the experimental and theoretical aspects of absorption spectroscopy of cold atomic hydrogen gas in a magnetostatic trap using a pulsed narrow-band source (bandwidth ~100 MHz) at the Lyman-~ wavelength (121.6 nm). A careful analysis of the measured absorption spectra enables us to determine non-destructively the temperature and the density of the trapped gas. The development of this diagnostic technique is important for future attempts to reach BoseEinstein condensation in trapped atomic hydrogen.

show abstract