Majorana Effect on Atomic Frequency Standards

Urabe, Shinji; Nakagiri, Koji; Ohta, Y.; Kobayashi, Masaki; Saburi, Y.

doi:10.1109/tim.1980.4314940

Cited by 28 publications

(8 citation statements)

References 7 publications

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“…选态磁铁  2 60 mm 上世纪 80年代日本的 Shinji与 Yasusada [9] 和Urabe等 [10] 完成了关于氢原子的量子态反转实验, 俄罗斯Humphrey 等 [11] , Boyko与Aleynikov [12] , Mikhail [13]…”

Section: 但受限于现有氢原子钟经选态后仍有50%以上无效态氢原子进入储存泡使得氢原子钟中长期频率稳定度指标难以继续提高unclassified

Simulation analysis of hydrogen atomic clock double state-selection beam optical system

Liang¹,

Xie²,

Chen³

et al. 2023

Acta Phys. Sin.

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Hydrogen maser utilises transition frequency of hydrogen atom in hyperfine energy level of ground state for precise timing. It has excellent frequency stability, especially in medium and short-term, and low frequency drift. It has been used as high-precision frequency standard in engineering fields such as time keeping, navigation, and very long baseline interferometry. Clock transition of hydrogen maser is transition between states of |F=1, mF=0> and |F=0, mF=0>. State selection is realized by state selection magnet, through which high energy atoms are converged and low energy atoms are dispersed. In conventional magnet state-selecting system, both atoms of |F=1, mF=0> states, which is required for the maser transition, and useless atoms of |F=1, mF=1> states are focused into storage bulb, which places restrictions on the medium and long-term frequency stability performance of hydrogen maser. In order to further improve quality of atomic transition spectral lines and the performance of hydrogen maser, double state-selection beam optical system which based on the Majorana transition mode was constructed through calculations and simulations. In this paper, we used Majorana method to invert atomic states. The magnetic field required for Majorana transition is established using two coils with reverse current, which are spaced 71 mm apart with and the coil axes aligned with the direction of atomic beam. Two additional pairs of transverse Helmholtz coils are spaced 22 mm apart set in the center of the state reversal to adjust the magnetic field zero point, which should coincide with the atomic beam to ensure a complete reversal of atomic polarity. The state reversal region is surrounded by four magnetic shields to reduce the influence of stray magnetic fields. Relationship between selected-state magnetic field gradient and distance of magnetic poles is analysed by simulation, and trajectories of the atoms in the high and low energy under different selected-state magnetic fields are calculated. The utilization and purity of high energy states atoms entering bulb atoms are obtained. The purity of the selected |F=1, mF=0> state atoms reaches 99% and the utilization rate is 58%. This is ideal for engineering applications. It effectively enhances the proportion of |F=1, mF=0> state atoms entering the atomic storage bulb and ensures utilization of atoms. We have verified the state-selection beam optical system through experiments. By turning on double state-selection system enhancement of the maser signal can be observed; By adjusting coils current of the double state-selection system, variation of maser signal with coils current can be observed, which verifies the effectiveness of double state-selection system.

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Section: 但受限于现有氢原子钟经选态后仍有50%以上无效态氢原子进入储存泡使得氢原子钟中长期频率稳定度指标难以继续提高unclassified

Simulation analysis of hydrogen atomic clock double state-selection beam optical system

Liang¹,

Xie²,

Chen³

et al. 2023

Acta Phys. Sin.

View full text Add to dashboard Cite

show abstract

“…Active servo control has also been applied to the reduction of magnetic field effects; one such system concentrates and senses the magnetic field within the outermost magnetic shield and controls a solenoid to compensate for ambient field changes [19]. Single-state hydrogen beam state selection systems [21]- [23] can improve magnetic performance as well as reduce cavity pulling. By preventing hydrogen atoms in undesired hyperfine states from entering the storage region these systems reduce spin-exchange relaxation, thereby increasing the line Q and decreasing cavity pulling; in addition, they substantially reduce collisional frequency shifts that make the maser susceptible to magnetic field variations [24].…”

Section: V Strategies For Reducing Systematic Frequency Variationsmentioning

confidence: 99%

Physics of systematic frequency variations in hydrogen masers

Mattison

1992

IEEE Trans. Ultrason., Ferroelect., Freq. Contr.

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The frequency stability of hydrogen masers for intervals longer than 10(4) s is currently limited by systematic processes. The physics of frequency-determining mechanisms internal to the maser that are susceptible to systematic variations, and the connections between these internal mechanisms and external environmental factors are discussed. From estimates of the magnitudes of systematic effects, it is found that the primary internal mechanisms limiting long-term maser frequency stability are cavity pulling, at the level of parts in 10(15) per day, and wall shift variations, at the level of parts in 10(16) to parts in 10(15) per day. Strategies for reducing systematic frequency variations are discussed.

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“…The gist of idea consists in using two state-selection magnets, which are separated by spin-flip region [6], instead of conventional state-selection magnet. In the new state-selection system (single-state) proposed by the authors, all of the undesirable atoms are eliminated from the hydrogen beam and, thus, only operational atoms are present in the storage bulb.…”

Section: Introductionmentioning

confidence: 99%

Active H-maser with increased power of the output signal

Boyko

Aleynikov

2013

2013 Joint European Frequency and Time Forum &Amp; International Frequency Control Symposium (EFTF/IFC)

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To improve short-time stability the amplification of the hydrogen maser output signal due to using the single-state selection and cooling the source cell is theoretically discussed. Hmaser theory basic aspects are sequentially developed in the introduction part. The results of the numerical calculation active H-maser power versus magnet parameters of specific selective system and source temperature are obtained. In conclusion, the theoretic prototype of maser, that has a short-time stability achieved 2.5×10 -14 for one second, is represented.

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Majorana Effect on Atomic Frequency Standards

Cited by 28 publications

References 7 publications

Simulation analysis of hydrogen atomic clock double state-selection beam optical system

Simulation analysis of hydrogen atomic clock double state-selection beam optical system

Physics of systematic frequency variations in hydrogen masers

Active H-maser with increased power of the output signal

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