1
|
Shu K, Tajima Y, Uozumi R, Miyamoto N, Shiraishi S, Kobayashi T, Ishida A, Yamada K, Gladen RW, Namba T, Asai S, Wada K, Mochizuki I, Hyodo T, Ito K, Michishio K, O'Rourke BE, Oshima N, Yoshioka K. Cooling positronium to ultralow velocities with a chirped laser pulse train. Nature 2024; 633:793-797. [PMID: 39261730 PMCID: PMC11424484 DOI: 10.1038/s41586-024-07912-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 08/06/2024] [Indexed: 09/13/2024]
Abstract
When laser radiation is skilfully applied, atoms and molecules can be cooled1-3, allowing the precise measurements and control of quantum systems. This is essential for the fundamental studies of physics as well as practical applications such as precision spectroscopy4-7, ultracold gases with quantum statistical properties8-10 and quantum computing. In laser cooling, atoms are slowed to otherwise unattainable velocities through repeated cycles of laser photon absorption and spontaneous emission in random directions. Simple systems can serve as rigorous testing grounds for fundamental physics-one such case is the purely leptonic positronium11,12, an exotic atom comprising an electron and its antiparticle, the positron. Laser cooling of positronium, however, has hitherto remained unrealized. Here we demonstrate the one-dimensional laser cooling of positronium. An innovative laser system emitting a train of broadband pulses with successively increasing central frequencies was used to overcome major challenges posed by the short positronium lifetime and the effects of Doppler broadening and recoil. One-dimensional chirp cooling was used to cool a portion of the dilute positronium gas to a velocity distribution of approximately 1 K in 100 ns. A major advancement in the field of low-temperature fundamental physics of antimatter, this study on a purely leptonic system complements work on antihydrogen13, a hadron-containing exotic atom. The successful application of laser cooling to positronium affords unique opportunities to rigorously test bound-state quantum electrodynamics and to potentially realize Bose-Einstein condensation14-18 in this matter-antimatter system.
Collapse
Affiliation(s)
- K Shu
- Photon Science Centre, School of Engineering, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, Japan
- Department of Applied Physics, School of Engineering, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo, Japan
| | - Y Tajima
- Department of Applied Physics, School of Engineering, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo, Japan
| | - R Uozumi
- Department of Applied Physics, School of Engineering, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo, Japan
| | - N Miyamoto
- Department of Applied Physics, School of Engineering, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo, Japan
| | - S Shiraishi
- Department of Applied Physics, School of Engineering, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo, Japan
| | - T Kobayashi
- Department of Applied Physics, School of Engineering, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo, Japan
| | - A Ishida
- Department of Physics, Graduate School of Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo, Japan.
| | - K Yamada
- Department of Physics, Graduate School of Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo, Japan
| | - R W Gladen
- Department of Physics, Graduate School of Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo, Japan
| | - T Namba
- International Centre for Elementary Particle Physics (ICEPP), The University of Tokyo, Hongo, Bunkyo-ku, Tokyo, Japan
| | - S Asai
- Department of Physics, Graduate School of Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo, Japan
| | - K Wada
- Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki, Japan
| | - I Mochizuki
- Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki, Japan
| | - T Hyodo
- Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki, Japan
| | - K Ito
- National Institute of Advanced Industrial Science and Technology (AIST), Umezono, Tsukuba, Ibaraki, Japan
| | - K Michishio
- National Institute of Advanced Industrial Science and Technology (AIST), Umezono, Tsukuba, Ibaraki, Japan
| | - B E O'Rourke
- National Institute of Advanced Industrial Science and Technology (AIST), Umezono, Tsukuba, Ibaraki, Japan
| | - N Oshima
- National Institute of Advanced Industrial Science and Technology (AIST), Umezono, Tsukuba, Ibaraki, Japan
| | - K Yoshioka
- Photon Science Centre, School of Engineering, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, Japan.
- Department of Applied Physics, School of Engineering, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo, Japan.
| |
Collapse
|
2
|
Trung NT, Duong NT, Hien NQ, Tap TD, Thanh ND. Investigation of ortho-positronium annihilation for porous materials with different geometries and topologies. Sci Rep 2023; 13:13707. [PMID: 37607980 PMCID: PMC10444843 DOI: 10.1038/s41598-023-40901-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 08/18/2023] [Indexed: 08/24/2023] Open
Abstract
In this work, we present the results of the ortho-positronium (o-Ps) annihilation lifetimes and nitrogen adsorption measurements for different porous materials and an approach for describing the annihilation of o-Ps in a pore, which results in a surface-volume formula (SVF) for calculating the pore-related o-Ps lifetime. This proposed formula gives the relationship between the o-Ps annihilation rate and the effective pore radius, bulk composition, and pore structure, including pore geometry and topology. The pore-related o-Ps lifetimes of different materials calculated by the SVF are consistent with experimental results for both micro- and mesopores (and macropores) with different geometries and topologies. The SVF is convenient for calculations of pore dimensions for many cases of metal organic frameworks and zeolites. This approach enables us to fully explain the temperature dependence of the o-Ps annihilation lifetime over a wide temperature range, 20-700 K.
Collapse
Affiliation(s)
- Nguyen Thanh Trung
- Institute of Physics, Vietnam Academy of Science and Technology, Ba Dinh, Hanoi, Vietnam.
| | - Nguyen Thuy Duong
- Vietnam Japan University, Vietnam National University, Hanoi, Vietnam
| | - Nguyen Quoc Hien
- Vietnam Atomic Energy Institute, 59 Ly Thuong Kiet, Hanoi, Vietnam
| | - Tran Duy Tap
- Faculty of Materials Science and Technology, University of Science, Vietnam National University, Ho Chi Minh City, Vietnam
| | - Nguyen Duc Thanh
- Research and Development Center for Advanced Technology, Cau Giay, Hanoi, Vietnam.
| |
Collapse
|
3
|
Kobayashi Y, Sato K, Yamawaki M, Michishio K, Oka T, Washio M. Positrons and positronium in macromolecules: Consequences of different charge states. Radiat Phys Chem Oxf Engl 1993 2023. [DOI: 10.1016/j.radphyschem.2022.110590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
|
4
|
Liu J, Guo J, Luo M, Wang Z, Zhang H, Ye B, Chen Z. Magnetic quenching of positronium studied by positron annihilation lifetime and Doppler broadening measurements. Radiat Phys Chem Oxf Engl 1993 2020. [DOI: 10.1016/j.radphyschem.2020.108712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
5
|
Michishio K, Chiari L, Tanaka F, Oshima N, Nagashima Y. A high-quality and energy-tunable positronium beam system employing a trap-based positron beam. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2019; 90:023305. [PMID: 30831693 DOI: 10.1063/1.5060619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Accepted: 01/17/2019] [Indexed: 06/09/2023]
Abstract
We constructed a new apparatus, built upon a trap-based slow positron beam, for the production of a collimated, energy-tunable positronium beam under ultra-high vacuum conditions employing the photodetachment of positronium negative ions. A slow positron generator consisting of a 22Na radioisotope (20 mCi) combined with a buffer-gas positron trap is employed to generate high-quality, nano-second positron bursts with a repetition rate of 1 Hz-1 kHz. The positron bursts are focused onto an efficient positron-to-positronium negative ion converter, a Na-coated W thin film in a transmission geometry, using a magnetic lens system. The ions emitted from the opposite surface of the film are electrostatically accelerated to a given energy and photodetached by a pulsed infrared laser to form a mono-energetic positronium beam with kinetic energies of 0.2 keV-3.3 keV. The achieved detection rate of Ps atoms is 23 cps at the energy of 3.3 keV with a signal-to-background ratio as high as 300. The energy spread of the beam was evaluated by comparing the result of the time-of-flight measurements and particle-tracking simulations. With the use of a collimator of 1 mm diameter, a coherent beam with an angular divergence of less than 0.3° is obtained. The obtained Ps beam, having a much higher quality than those reported hitherto, will open up a new field of experimental investigations, such as Ps interacting with a variety of materials and fundamental studies on Ps spectroscopy.
Collapse
Affiliation(s)
- K Michishio
- Department of Physics, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo 162-8601, Japan
| | - L Chiari
- Department of Physics, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo 162-8601, Japan
| | - F Tanaka
- Department of Physics, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo 162-8601, Japan
| | - N Oshima
- National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568, Japan
| | - Y Nagashima
- Department of Physics, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo 162-8601, Japan
| |
Collapse
|
6
|
Zhou Y, Mao W, Li Q, Wang J, He C. Formation and annihilation of positronium in silica aerogels under atmosphere of oxygen and nitrogen mixture. Chem Phys 2015. [DOI: 10.1016/j.chemphys.2015.07.030] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
7
|
Consolati G, Ferragut R, Galarneau A, Di Renzo F, Quasso F. Mesoporous materials for antihydrogen production. Chem Soc Rev 2013; 42:3821-32. [PMID: 23250616 DOI: 10.1039/c2cs35454c] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Antimatter is barely known by the chemist community and this article has the vocation to explain how antimatter, in particular antihydrogen, can be obtained, as well as to show how mesoporous materials could be used as a further improvement for the production of antimatter at very low temperatures (below 1 K). The first experiments with mesoporous materials highlighted in this review show very promising and exciting results. Mesoporous materials such as mesoporous silicon, mesoporous material films, pellets of MCM-41 and silica aerogel show remarkable features for antihydrogen formation. Yet, the characteristics for the best future mesoporous materials (e.g. pore sizes, pore connectivity, shape, surface chemistry) remain to be clearly identified. For now among the best candidates are pellets of MCM-41 and aerogel with pore sizes between 10 and 30 nm, possessing hydrophobic patches on their surface to avoid ice formation at low temperature. From a fundamental standpoint, antimatter experiments could help to shed light on open issues, such as the apparent asymmetry between matter and antimatter in our universe and the gravitational behaviour of antimatter. To this purpose, basic studies on antimatter are necessary and a convenient production of antimatter is required. It is exactly where mesoporous materials could be very useful.
Collapse
Affiliation(s)
- Giovanni Consolati
- Department of Aerospace Science and Technology, Politecnico di Milano, via La Masa 34, 20156, Milano, Italy.
| | | | | | | | | |
Collapse
|
8
|
Mariazzi S, Bettotti P, Brusa RS. Positronium cooling and emission in vacuum from nanochannels at cryogenic temperature. PHYSICAL REVIEW LETTERS 2010; 104:243401. [PMID: 20867299 DOI: 10.1103/physrevlett.104.243401] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2010] [Indexed: 05/29/2023]
Abstract
High formation yield and a meaningful cooled fraction of positronium below room temperature were obtained by implanting positrons in a silicon target in which well-controlled oxidized nanochannels (5-8 nm in diameter) perpendicular to the surface were produced. We show that by implanting positrons at 7 keV in the target held at 150 K, about 27% of positrons form positronium that escapes into the vacuum. Around 9% of the escaped positronium is cooled by collision with the walls of nanochannels and is emitted with a Maxwellian beam at 150 K. Because positronium quantum confinement limits the minimum achievable positronium energy, the tuning of the nanochannel's size is crucial for obtaining positronium gases in vacuum at very low temperature.
Collapse
Affiliation(s)
- Sebastiano Mariazzi
- Dipartimento di Fisica, Università di Trento and INFN, Gruppo collegato di Trento, Via Sommarive 14, I-38050 Povo, Trento, Italy
| | | | | |
Collapse
|
9
|
Cassidy DB, Mills AP. Interactions between positronium atoms in porous silica. PHYSICAL REVIEW LETTERS 2008; 100:013401. [PMID: 18232757 DOI: 10.1103/physrevlett.100.013401] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2007] [Indexed: 05/25/2023]
Abstract
Interactions between pairs of positronium (Ps) atoms confined in porous silica films have been directly observed for the first time. Because of selection rules, the nature of such interactions should depend on the structure of the porous medium: if a Ps surface state exists, dipositronium (Ps2) molecules may be created, and if there is a continuum of cavity energy levels, spin exchanging collisions may occur. Using two structurally different silica films, we have been able to isolate and study these two processes. Our data indicate that Ps2 formation occurs primarily via a Langmuir-Hinshelwood-type mechanism on the internal pore surfaces, with an interaction length of the order of 7 x 10(-8) cm, and that the effective cross section for nonthermalized Ps-Ps spin exchange quenching in porous silica is around 9 x 10(-15) cm2.
Collapse
Affiliation(s)
- D B Cassidy
- Department of Physics and Astronomy, University of California, Riverside, California 92521-0413, USA
| | | |
Collapse
|
10
|
|
11
|
Saito H, Hyodo T. Experimental evidence for spin-orbit interactions in positronium-Xe collisions. PHYSICAL REVIEW LETTERS 2006; 97:253402. [PMID: 17280351 DOI: 10.1103/physrevlett.97.253402] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2006] [Indexed: 05/13/2023]
Abstract
Spin-orbit interaction of positronium (Ps) with the surrounding atoms, predicted by Mitroy and Novikov [Phys. Rev. Lett. 90, 183202 (2003)], has been detected experimentally. We have found that the lifetime of the magnetically unperturbed ortho-Ps in Xe gas of 1 atm decreases significantly when a magnetic field of 1.0 T is applied. This decrease is attributed to the Ps spin conversion caused by spin-orbit interaction during Ps-Xe collision. The annihilation cross section of ortho-Ps due to this interaction has been determined to be 3 times as large as that expected by Mitroy and Novikov.
Collapse
Affiliation(s)
- Haruo Saito
- Institute of Physics, Graduate School of Arts and Sciences, University of Tokyo, 3-8-1, Komaba, Tokyo, 153-8902, Japan.
| | | |
Collapse
|
12
|
Eijt S, van Veen A, Falub C, Galindo R, Schut H, Mijnarends P, de Theije F, Balkenende A. Depth-selective 2D-ACAR studies on low-k dielectric thin films. Radiat Phys Chem Oxf Engl 1993 2003. [DOI: 10.1016/s0969-806x(03)00184-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
13
|
On the peculiarities of positron annihilation features in silicalite-1 and Y-zeolites. Radiat Phys Chem Oxf Engl 1993 2000. [DOI: 10.1016/s0969-806x(00)00244-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
14
|
Can a newly developed AMOC technique be applied to determine the para-positronium lifetime? Radiat Phys Chem Oxf Engl 1993 2000. [DOI: 10.1016/s0969-806x(00)00258-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
15
|
Takada S, Iwata T, Kawashima K, Saito H, Nagashima Y, Hyodo T. Thermalization of positronium atoms studied with time-resolved angular correlation of annihilation radiation. Radiat Phys Chem Oxf Engl 1993 2000. [DOI: 10.1016/s0969-806x(00)00259-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
16
|
Ito K, Nakanishi H, Ujihira Y. Extension of the Equation for the Annihilation Lifetime of ortho-Positronium at a Cavity Larger than 1 nm in Radius. J Phys Chem B 1999. [DOI: 10.1021/jp9831841] [Citation(s) in RCA: 144] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Kenji Ito
- Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan, Department of Pathobiology, University of Washington, Seattle, Washington, and Molecumetics, Ltd., 2023 120th Ave. NE, Bellevue, Washington 98005
| | - Hiroshi Nakanishi
- Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan, Department of Pathobiology, University of Washington, Seattle, Washington, and Molecumetics, Ltd., 2023 120th Ave. NE, Bellevue, Washington 98005
| | - Yusuke Ujihira
- Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan, Department of Pathobiology, University of Washington, Seattle, Washington, and Molecumetics, Ltd., 2023 120th Ave. NE, Bellevue, Washington 98005
| |
Collapse
|
17
|
|
18
|
Lahtinen J, Hautojärvi P. Characterization of Alumina-Supported Model Catalysts Using Positronium Lifetime Technique. J Phys Chem B 1997. [DOI: 10.1021/jp962638w] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- J. Lahtinen
- Laboratory of Physics, Helsinki University of Technology, 02150 Espoo, Finland
| | - P. Hautojärvi
- Laboratory of Physics, Helsinki University of Technology, 02150 Espoo, Finland
| |
Collapse
|