{"title":"反氢的绝热膨胀冷却","authors":"M. Ahmadiet al.(The ALPHA Collaboration)","doi":"10.1103/physrevresearch.6.l032065","DOIUrl":null,"url":null,"abstract":"Magnetically trapped antihydrogen atoms can be cooled by expanding the volume of the trap in which they are confined. We report a proof-of-principle experiment in which antiatoms are deliberately released from expanded and static traps. Antiatoms escape at an average trap depth of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>0.08</mn><mo>±</mo><mn>0.01</mn><mspace width=\"0.28em\"></mspace><mi mathvariant=\"normal\">K</mi></mrow></math> (statistical errors only) from the expanded trap while they escape at average depths of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>0.22</mn><mo>±</mo><mn>0.01</mn></mrow></math> and <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>0.17</mn><mo>±</mo><mn>0.01</mn><mspace width=\"0.28em\"></mspace><mi mathvariant=\"normal\">K</mi></mrow></math> from two different static traps. (We employ temperature-equivalent energy units.) Detailed simulations qualitatively agree with the escape times measured in the experiment and show a decrease of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>38</mn><mo>%</mo></mrow></math> (statistical <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mtext>error</mtext><mo><</mo><mn>0.2</mn><mo>%</mo></mrow></math>) in the mean energy of the population after the trap expansion without significantly increasing antiatom loss compared to typical static confinement protocols. This change is bracketed by the predictions of one-dimensional and three-dimensional semianalytic adiabatic expansion models. These experimental, simulational, and model results are consistent with obtaining an adiabatically cooled population of antihydrogen atoms that partially exchanged energy between axial and transverse degrees of freedom during the trap expansion. This result is important for future antihydrogen gravitational experiments which rely on adiabatic cooling, and it will enable antihydrogen cooling beyond the fundamental limits of laser cooling.","PeriodicalId":20546,"journal":{"name":"Physical Review Research","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Adiabatic expansion cooling of antihydrogen\",\"authors\":\"M. Ahmadiet al.(The ALPHA Collaboration)\",\"doi\":\"10.1103/physrevresearch.6.l032065\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Magnetically trapped antihydrogen atoms can be cooled by expanding the volume of the trap in which they are confined. We report a proof-of-principle experiment in which antiatoms are deliberately released from expanded and static traps. Antiatoms escape at an average trap depth of <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><mrow><mn>0.08</mn><mo>±</mo><mn>0.01</mn><mspace width=\\\"0.28em\\\"></mspace><mi mathvariant=\\\"normal\\\">K</mi></mrow></math> (statistical errors only) from the expanded trap while they escape at average depths of <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><mrow><mn>0.22</mn><mo>±</mo><mn>0.01</mn></mrow></math> and <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><mrow><mn>0.17</mn><mo>±</mo><mn>0.01</mn><mspace width=\\\"0.28em\\\"></mspace><mi mathvariant=\\\"normal\\\">K</mi></mrow></math> from two different static traps. (We employ temperature-equivalent energy units.) Detailed simulations qualitatively agree with the escape times measured in the experiment and show a decrease of <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><mrow><mn>38</mn><mo>%</mo></mrow></math> (statistical <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><mrow><mtext>error</mtext><mo><</mo><mn>0.2</mn><mo>%</mo></mrow></math>) in the mean energy of the population after the trap expansion without significantly increasing antiatom loss compared to typical static confinement protocols. This change is bracketed by the predictions of one-dimensional and three-dimensional semianalytic adiabatic expansion models. These experimental, simulational, and model results are consistent with obtaining an adiabatically cooled population of antihydrogen atoms that partially exchanged energy between axial and transverse degrees of freedom during the trap expansion. This result is important for future antihydrogen gravitational experiments which rely on adiabatic cooling, and it will enable antihydrogen cooling beyond the fundamental limits of laser cooling.\",\"PeriodicalId\":20546,\"journal\":{\"name\":\"Physical Review Research\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2024-09-16\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Physical Review Research\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.1103/physrevresearch.6.l032065\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Physical Review Research","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1103/physrevresearch.6.l032065","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Magnetically trapped antihydrogen atoms can be cooled by expanding the volume of the trap in which they are confined. We report a proof-of-principle experiment in which antiatoms are deliberately released from expanded and static traps. Antiatoms escape at an average trap depth of (statistical errors only) from the expanded trap while they escape at average depths of and from two different static traps. (We employ temperature-equivalent energy units.) Detailed simulations qualitatively agree with the escape times measured in the experiment and show a decrease of (statistical ) in the mean energy of the population after the trap expansion without significantly increasing antiatom loss compared to typical static confinement protocols. This change is bracketed by the predictions of one-dimensional and three-dimensional semianalytic adiabatic expansion models. These experimental, simulational, and model results are consistent with obtaining an adiabatically cooled population of antihydrogen atoms that partially exchanged energy between axial and transverse degrees of freedom during the trap expansion. This result is important for future antihydrogen gravitational experiments which rely on adiabatic cooling, and it will enable antihydrogen cooling beyond the fundamental limits of laser cooling.