-
稳定的高强度原子束流源是很多精密测量实验的关键. 亚稳态(
$2^3{\rm S}$ )氦原子的精密光谱测量在检验量子电动力学、测定精细结构常数研究中受到重要关注. 本文利用激光冷却方法增强束流强度、通过塞曼减速器降低原子的纵向速度, 并利用反馈控制稳定束流强度. 实验测得, 所产生的亚稳态氦原子连续束流在$(100\pm 3.6)$ m/s 速度下, 强度达$5.8\times 10^{12}$ atoms/(s·sr), 相对稳定度为 0.021%. 利用该原子束, 示范了在仅0.1%的饱和光强条件下进行$^4{\rm{He}}$ 原子$2^3{\rm S}—2^3{\rm P}$ 跃迁的光谱探测, 此时由探测光功率带来的频移低于1 kHz.A stable high-intensity atomic beam source plays a key role in many precision measurements. The precision spectroscopy of slow metastable ($2^3{\rm S}$ ) helium atoms is of great interest in testing quantum electrodynamics and determining the fine structure constant. By improving the source cavity structure and using laser cooling method, the beam flux is greatly enhanced. The added Zeeman slower reduces the longitudinal velocity of atoms, and at the same time increases the beam brightness of atoms at one single speed. Near the back end of Zeeman slower, a two-dimensional magneto-optical trap is added to collimate and focus the atomic beam. In addition, A beam stabilizing system is developed by using feedback control method. By changing the frequency of transverse cooling laser to change the cooling efficiency, the fluctuation of atomic beam intensity can be compensated in real time, and then the beam intensity can be stabilized at the target number. Experiments show that the continuous beam of metastable helium atoms at a velocity of$(100\pm 3.6)$ m/s has an intensity of$5.8\times10^{12}$ atoms/s/sr and a relative stability of 0.021%. In the experiment of precise spectral measurement based on atomic beam, the narrow longitudinal velocity distribution reduces the lateral Doppler broadening effect, and the lower longitudinal velocity also reasonably reduces the systematic error caused by the first-order Doppler effect. The atomic beam with such high intensity and stability in a single momentum and quantum state obviously improves the signal-to-noise ratio of the spectrum, and further reduces the statistical error of the results in the same detection time. Using this atomic beam, we demonstrated spectroscopy of the$2^3{\rm S}-2^3{\rm P}$ transition of$^4{\rm{He}}$ under the condition of only 0.1% of the saturated intensity. At this time, the full width at half maximum of the spectral peak is almost close to the natural line width, but the spectral signal-to-noise ratio is still better than 400 and the frequency shift caused by the detection laser power can be less than 1 kHz. This kind of spectral detection at low power can effectively reduce the power-dependent frequency shift, thus obtaining more reliable detection results. This metastable helium atom beam experimental system can also be used as a reference for similar precision measurement experiments.-
Keywords:
- helium /
- atomic beam /
- precision measurement /
- quantum electrodynamics
[1] Pachucki K, Yerokhin, V A 2015 J. Phys. Chem. Ref. Data 44 031206
Google Scholar
[2] Salumbides E J, Koelemeij J C J, Komasa J, Pachucki K, Eikema K S E, Ubachs W 2013 Phys. Rev. D 87 112008
Google Scholar
[3] Ficek F, Kimball D F J, Kozlov M G, Leefer N, Pustelny S, Budker D 2017 Phys. Rev. A 95 032505
Google Scholar
[4] Pachucki K, Yerokhin V A 2010 Phys. Rev. Lett. 104 070403
Google Scholar
[5] Drake G W F 2002 Can. J. Phys. 80 1195
[6] Pachucki K 2006 Phys. Rev. Lett. 97 013002
Google Scholar
[7] Ottermann C R, Köbschall G, Maurer K, Röhrich K, Schmitt Ch, Walther V H 1985 Nucl. Phys. A 436 688
Google Scholar
[8] Sick I 2015 J. Phys. Chem. Ref. Data 44 031213
Google Scholar
[9] Yerokhin V A, Pachucki K 2016 Phys. Rev. A 94 052508
Google Scholar
[10] Pahcucki K, Patkos V, Yerokhin V A 2017 Phys. Rev. A 95 062510
Google Scholar
[11] Feng G P, Zheng X, Sun Y R, Hu S M 2015 Phys. Rev. A 91 030502
Google Scholar
[12] Zheng X, Sun Y R, Chen J J, Jiang W, Pachucki K, Hu S M 2017 Phys. Rev. Lett. 119 263002
Google Scholar
[13] Storry C H, Hessels E A 1998 Phys. Rev. A 58 R8
Google Scholar
[14] George M C, Lombardi L D, Hessels E A 2001 Phys. Rev. Lett. 87 173002
Google Scholar
[15] Minardi F, Bianchini G, Pastor P C, Giusfredi G, Pavone F S, Inguscio M 1999 Phys. Rev. Lett. 82 1112
Google Scholar
[16] Castillega J, Livingston D, Sanders A, Shiner D 2000 Phys. Rev. Lett. 84 4321
Google Scholar
[17] Pastor P C, Giusfredi G, Natale P D, Hagel G, Mauro C D, Inguscio M 2004 Phys. Rev. Lett. 92 023001
Google Scholar
[18] Zelevinsky T, Farkas D, Gabrilse G 2005 Phys. Rev. Lett. 95 203001
Google Scholar
[19] van Rooij R, Borbely J S, Simonet J, Hoogerland M D, Eikema K S E, Rozendaal R A, Vassen W 2011 Science 333 196
Google Scholar
[20] Rengelink R J, van der Werf Y, Notermans R P M J W, Jannin R, Eikema K S E, Hoogerland M D, Vassen W 2018 Nat. Phys. 14 1132
Google Scholar
[21] Zheng X, Sun Y R, Chen J J, Wen J L, Hu S M 2019 Phys. Rev. A 99 032506
Google Scholar
[22] 冯高平, 孙羽, 郑昕, 胡水明 2014 物理学报 63 123201
Google Scholar
Feng G P, Sun Y, Zheng X, Hu S M 2014 Acta Phys. Sin. 63 123201
Google Scholar
[23] 孙羽, 冯高平, 程存峰, 涂乐义, 潘虎, 杨国民, 胡水明 2012 物理学报 61 170601
Google Scholar
Sun Y, Feng G P, Cheng C F, Tu L Y, Pan H, Yang G M, Hu S M 2012 Acta Phys. Sin. 61 170601
Google Scholar
[24] Labeyrie G, Browaeys A, Rooijakkers W, Voelker D, Grosperrin J, Wanner B, Westbrook C I, Aspect A 1999 Eur. Phys. J. D 7 341
[25] Hoogerland M D, Driessen J P J, Vredenbregt E J D, Megens H J L, Schuwer M P, Beijerinck H C W, Van Leeuwen K A K 1996 Appl. Phys. B 62 323
[26] Fahey D W, Parks W F, Schearer L D 1980 J. Phys. E: Sci. Instrum. 13 381
Google Scholar
[27] Rothe E W, Neynaber R H, Trujillo S M 1965 J. Chem. Phys. 42 3310
Google Scholar
[28] Cheng C F, Jiang W, Yang G M, Sun Y R, Pan H, Gao Y, Liu A W, Hu S M 2010 Rev. Sci. Instrum. 81 123106
Google Scholar
[29] Rooijakkers W, Hogervorst W, Vassen W 1997 Opt. Commun. 135 149
Google Scholar
[30] Rooijakkers W, Hogervorst W, Vassen W 1996 Opt. Commun. 135 321
[31] Swansson J A, Baldwin K G H, Hoogerland M D, Truscott A G, Buckman S J 2004 Appl. Phys. B 79 485
Google Scholar
[32] Hodgman S S, Dall R G, Byron L J, Baldwin K G H, Buckman S J, Truscott A G 2009 Phys. Rev. Lett. 103 053002
Google Scholar
[33] Yan Z C, Drake G W F 1994 Phys. Rev. A 50 R1980
Google Scholar
[34] Minardi F, Artoni M, Cancio P, Inguscio M, Giusfredi G, Carusotto I 1999 Phys. Rev. A 60 4164
Google Scholar
[35] Artoni M, Carusotto I, Minardi F 2000 Phys. Rev. A 62 023402
Google Scholar
[36] Zheng X, Sun Y R, Chen J J, Jiang W, Pachucki K, Hu S M 2017 Phys. Rev. Lett. 118 063001
Google Scholar
[37] Smiciklas M, Shiner D 2010 Phys. Rev. Lett. 105 123001
Google Scholar
-
图 1 氦原子
$2^3 {\rm S}—2^3 {\rm P}$ 跃迁频率测量实验装置示意图. 插图为$2^3 {\rm S}—2^3 {\rm P}$ 跃迁能级图. ECDL, 外腔式半导体激光器; EOM, 电光调制器; GPS, 全球定位系统; OFC, 光学频率梳; AOM, 声光调制器; BS, 分束棱镜; ULE, 超低膨胀系数标准具; FM, 幅度调制Fig. 1. Schematic diagram of the experimental setup for measuring the
$2^3 {\rm S}-2^3 {\rm P}$ transition frequency of helium. Inset: Energy diagram of the$2 ^3 {\rm S}-2 ^3 {\rm P}$ transitions. ECDL, external cavity diode laser; EOM, electro-optical modulator; GPS, global positioning system; OFC, optical frequency comb; AOM, acoustic-optical modulator; BS, beam splitter; PZT, piezoelectric transducer; ULE, ultralow expansion; FM, amplitude modulation.
图 3 速度为
$(100\pm3.6)$ m/s的氦原子束流强度Fig. 3. Beam intensity evolution of helium atoms at
$(100\pm3.6)$ m/s.
图 4
$2^3 {\rm S}_1—2^3 {\rm P}_0$ 跃迁测量实验过程 (a) 光学抽运; (b) 光谱探测Fig. 4. Experimental procedure of the measurement of the
$2^3 {\rm S}_1-2^3 {\rm P}_0$ transition: (a) Optical pumping; (b) spectroscopy probing.
图 5
$2^3 {\rm S}_1—2^3 {\rm P}_0$ 跃迁单次扫描所获得光谱Fig. 5. A single scan spectrum of
$2^3 {\rm S}_1 - 2^3 {\rm P}_0$ transition. -
[1] Pachucki K, Yerokhin, V A 2015 J. Phys. Chem. Ref. Data 44 031206
Google Scholar
[2] Salumbides E J, Koelemeij J C J, Komasa J, Pachucki K, Eikema K S E, Ubachs W 2013 Phys. Rev. D 87 112008
Google Scholar
[3] Ficek F, Kimball D F J, Kozlov M G, Leefer N, Pustelny S, Budker D 2017 Phys. Rev. A 95 032505
Google Scholar
[4] Pachucki K, Yerokhin V A 2010 Phys. Rev. Lett. 104 070403
Google Scholar
[5] Drake G W F 2002 Can. J. Phys. 80 1195
[6] Pachucki K 2006 Phys. Rev. Lett. 97 013002
Google Scholar
[7] Ottermann C R, Köbschall G, Maurer K, Röhrich K, Schmitt Ch, Walther V H 1985 Nucl. Phys. A 436 688
Google Scholar
[8] Sick I 2015 J. Phys. Chem. Ref. Data 44 031213
Google Scholar
[9] Yerokhin V A, Pachucki K 2016 Phys. Rev. A 94 052508
Google Scholar
[10] Pahcucki K, Patkos V, Yerokhin V A 2017 Phys. Rev. A 95 062510
Google Scholar
[11] Feng G P, Zheng X, Sun Y R, Hu S M 2015 Phys. Rev. A 91 030502
Google Scholar
[12] Zheng X, Sun Y R, Chen J J, Jiang W, Pachucki K, Hu S M 2017 Phys. Rev. Lett. 119 263002
Google Scholar
[13] Storry C H, Hessels E A 1998 Phys. Rev. A 58 R8
Google Scholar
[14] George M C, Lombardi L D, Hessels E A 2001 Phys. Rev. Lett. 87 173002
Google Scholar
[15] Minardi F, Bianchini G, Pastor P C, Giusfredi G, Pavone F S, Inguscio M 1999 Phys. Rev. Lett. 82 1112
Google Scholar
[16] Castillega J, Livingston D, Sanders A, Shiner D 2000 Phys. Rev. Lett. 84 4321
Google Scholar
[17] Pastor P C, Giusfredi G, Natale P D, Hagel G, Mauro C D, Inguscio M 2004 Phys. Rev. Lett. 92 023001
Google Scholar
[18] Zelevinsky T, Farkas D, Gabrilse G 2005 Phys. Rev. Lett. 95 203001
Google Scholar
[19] van Rooij R, Borbely J S, Simonet J, Hoogerland M D, Eikema K S E, Rozendaal R A, Vassen W 2011 Science 333 196
Google Scholar
[20] Rengelink R J, van der Werf Y, Notermans R P M J W, Jannin R, Eikema K S E, Hoogerland M D, Vassen W 2018 Nat. Phys. 14 1132
Google Scholar
[21] Zheng X, Sun Y R, Chen J J, Wen J L, Hu S M 2019 Phys. Rev. A 99 032506
Google Scholar
[22] 冯高平, 孙羽, 郑昕, 胡水明 2014 物理学报 63 123201
Google Scholar
Feng G P, Sun Y, Zheng X, Hu S M 2014 Acta Phys. Sin. 63 123201
Google Scholar
[23] 孙羽, 冯高平, 程存峰, 涂乐义, 潘虎, 杨国民, 胡水明 2012 物理学报 61 170601
Google Scholar
Sun Y, Feng G P, Cheng C F, Tu L Y, Pan H, Yang G M, Hu S M 2012 Acta Phys. Sin. 61 170601
Google Scholar
[24] Labeyrie G, Browaeys A, Rooijakkers W, Voelker D, Grosperrin J, Wanner B, Westbrook C I, Aspect A 1999 Eur. Phys. J. D 7 341
[25] Hoogerland M D, Driessen J P J, Vredenbregt E J D, Megens H J L, Schuwer M P, Beijerinck H C W, Van Leeuwen K A K 1996 Appl. Phys. B 62 323
[26] Fahey D W, Parks W F, Schearer L D 1980 J. Phys. E: Sci. Instrum. 13 381
Google Scholar
[27] Rothe E W, Neynaber R H, Trujillo S M 1965 J. Chem. Phys. 42 3310
Google Scholar
[28] Cheng C F, Jiang W, Yang G M, Sun Y R, Pan H, Gao Y, Liu A W, Hu S M 2010 Rev. Sci. Instrum. 81 123106
Google Scholar
[29] Rooijakkers W, Hogervorst W, Vassen W 1997 Opt. Commun. 135 149
Google Scholar
[30] Rooijakkers W, Hogervorst W, Vassen W 1996 Opt. Commun. 135 321
[31] Swansson J A, Baldwin K G H, Hoogerland M D, Truscott A G, Buckman S J 2004 Appl. Phys. B 79 485
Google Scholar
[32] Hodgman S S, Dall R G, Byron L J, Baldwin K G H, Buckman S J, Truscott A G 2009 Phys. Rev. Lett. 103 053002
Google Scholar
[33] Yan Z C, Drake G W F 1994 Phys. Rev. A 50 R1980
Google Scholar
[34] Minardi F, Artoni M, Cancio P, Inguscio M, Giusfredi G, Carusotto I 1999 Phys. Rev. A 60 4164
Google Scholar
[35] Artoni M, Carusotto I, Minardi F 2000 Phys. Rev. A 62 023402
Google Scholar
[36] Zheng X, Sun Y R, Chen J J, Jiang W, Pachucki K, Hu S M 2017 Phys. Rev. Lett. 118 063001
Google Scholar
[37] Smiciklas M, Shiner D 2010 Phys. Rev. Lett. 105 123001
Google Scholar
下载:
计量
- 文章访问数: 5743
- PDF下载量: 100
- 被引次数: 0
