Erratum: Radiative lifetime and energy of the low-energy isomeric level in 
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msup><mml:mrow /><mml:mn>229</mml:mn></mml:msup><mml:mi>Th</mml:mi></mml:mrow></mml:math>
 [Phys. Rev. C 
<b>92</b>
, 054324 (2015)]

Tkalya, E. V.; Schneider, Christian; Jeet, Justin; Hudson, Eric R.

doi:10.1103/physrevc.95.039902

Cited by 38 publications

(76 citation statements)

References 6 publications

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“…Second, the radiative lifetime of 229m Th was theoretically predicted to be in the range of hours [12][13][14], leading to long required detection times when searching for a radiative decay channel. This has led to the assumption that the required time for laserbased scanning of the large energy range of 1 eV would be prohibitively long.…”

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confidence: 99%

“…The radiative decay rate A is related to the radiative isomeric lifetime τ γ via A = 1/τ γ . In case of 229m Th no conclusive experimental value for the radiative isomeric lifetime has been reported and there is currently no consensus on τ γ from theory [12][13][14]. For the following we will conservatively assume a value of τ γ ≈ 10 4 s, which lies on the upper limit of the theoretically predicted isomeric lifetime and for this reason leads to the smallest coupling.…”

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confidence: 99%

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A Laser Excitation Scheme for Th229m

et al. 2017

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Direct laser excitation of the lowest known nuclear excited state in 229 Th has been a longstanding objective. It is generally assumed that reaching this goal would require a considerably reduced uncertainty of the isomer's excitation energy compared to the presently adopted value of (7.8 ± 0.5) eV. Here we present a direct laser excitation scheme for 229m Th, which circumvents this requirement. The proposed excitation scheme makes use of already existing laser technology and therefore paves the way for nuclear laser spectroscopy. In this concept, the recently experimentally observed internal-conversion decay channel of the isomeric state is used for probing the isomeric population. A signal-to-background ratio of better than 10 4 and a total measurement time of less than three days for laser scanning appear to be achievable.Direct nuclear laser excitation has come closer into reach within the past years, partly due to the development of free-electron-laser technology. Such ideas are typically dealing with the excitation of nuclear states in the energy range of at least a few keV or above [1,2]. However, there is one exceptional nuclear state known for the last 40 years with a significantly lower energy of presumably below 10 eV [3,4]. An excitation energy of (7.8 ± 0.5) eV, corresponding to (159 ± 11) nm wavelength or ∼ 1900 THz, is by today the most accepted value for the isomeric first excited state of 229 Th [5,6]. This state conceptionally allows for direct nuclear laser excitation using solid-state laser technology and was proposed for the development of a nuclear clock of extremely high stability, due to an expected high resilience against external influences and a radiative lifetime in the range of minutes to hours [7][8][9][10]. It is generally assumed that direct nuclear laser excitation of 229m Th requires a considerably improved knowledge of the isomeric transition energy (see e.g. Ref.[11] and references therein). The reasons are that, first, the present uncertainty in the knowledge of the isomeric energy value is still rather large. The currently best energy value of 7.8±0.5 eV leads to an energy range of at least 1 eV (corresponding to 2.4·1014 Hz) to be scanned when searching for the isomeric excitation. Second, the radiative lifetime of 229m Th was theoretically predicted to be in the range of hours [12][13][14], leading to long required detection times when searching for a radiative decay channel. This has led to the assumption that the required time for laserbased scanning of the large energy range of 1 eV would be prohibitively long. In order to shorten the required scanning times, there are worldwide efforts ongoing to decrease the uncertainty of the transition energy, which would bring the isomeric state into realistic reach of direct laser excitation (see e.g. Refs. [15-18]). A recent review is found in Ref. [11].Here we propose a different approach, which allows for a direct laser excitation of 229m Th without the requirement of an improved knowledge of the transition energy. As the requi...

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A Laser Excitation Scheme for Th229m

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“…Potential possibilities to achieve the level of 10 −19 become clearer for nuclear clocks [13][14][15][16] and for highly charged ions [17][18][19]. Great fundamental (e.g., in tests of fundamental physical theories such as QED, QCD, unification theories, cosmology, dark matter searches, etc.)…”

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Synthetic frequency protocol for Ramsey spectroscopy of clock transitions

et al. 2016

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We develop an universal method to significantly suppress probe-induced shifts in any types of atomic clocks using the Ramsey spectroscopy. Our approach is based on adaptation of the synthetic frequency concept [V. I. Yudin, et al., Phys. Rev. Lett. 107, 030801 (2011) At the present time, huge progress occurs for highprecision optical atomic clocks based on both neutral atoms in optical lattices [1][2][3][4][5][6][7][8] and trapped ions [9][10][11][12]. Exceptional accuracy and stability at the 10 −17 -10level are achieved. Potential possibilities to achieve the level of 10 −19 become clearer for nuclear clocks [13-16] and for highly charged ions [17][18][19]. Great fundamental (e.g., in tests of fundamental physical theories such as QED, QCD, unification theories, cosmology, dark matter searches, etc.) and practical (navigation and information systems, gravity-geopotential surveying) importance of the current and long-range researches is wellknown and unquestionable. Current state, concomitant problems, and future prospects are well presented in the review [20].On the way to these remarkable achievements, different barriers arise, which require the development of new unconventional approaches. As an example, for some of the promising clock systems, one of the key problems is the frequency shift of the clock transition due to the excitation pulses themselves. For the case of magnetically induced spectroscopy [21,22] these shifts (quadratic Zeeman and ac-Stark shifts) could ultimately limit the achievable performance. Moreover, for ultranarrow transitions (e.g., electric octupole [23] and twophoton transitions [24,25]) the ac-Stark shift can be so large in some cases to rule out high accuracy clock performance at all. A similar limitation exists for clocks based on direct frequency comb spectroscopy [26,27] due to ac-Stark shifts induced by large numbers of off-resonant * Electronic address: viyudin@mail.ru laser modes.Unconventional solution to this important problem was proposed in the paper [28], in which so-called hyperRamsey method has been developed. Soon this approach was successfully realized in [29], where the huge suppression (by four orders of magnitude) of probe-induced shifts was experimentally demonstrated (see also [9]). However, a potential of this method was not going to be settled. In the experimental-theoretical paper [30] a 'stunning' result was recently shown: certain simple modification allows, in principle, totally(!) to exclude probeinduced shifts. Other hyper-Ramsey modification, having the same efficiency, was very soon proposed in the theoretical paper [31]. Because these phenomenal results can have far-reaching consequences for development of atomic clocks, it requires utterly thorough investigation of the schemes [30,31]. Besides, undoubted importance has a search of new variants to suppress probe-induced shifts with the near extremal efficiency.In this paper, we develop an universal method to dramatically suppress probe-induced shifts and their fluctuations in any type of atomic clock...

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“…is the reduced probability of the nuclear isomeric transition in Weisskopf's units [64] and we have used that [34]. The electron matrix element of the M 1 transition [18] reads as…”

Section: Magnetic Hyperfine Structure and Mixing Of Sublevelsmentioning

confidence: 99%

“…The low lying 3/2 + (7.8 ± 0.5 eV) state [1,2] of the 229 Th nucleus has been the subject of intense experimental [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] and theoretical research [17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34] in the past decades. The interest is caused by new possibilities which are emerging in the study of such unusual nuclear level.…”

Section: Introductionmentioning

confidence: 99%

Magnetic hyperfine structure of the ground-state doublet in highly charged ionsTh89+,87+229and the Bohr-Weisskopf effect

Tkalya

Николаев

2016

Phys. Rev. C

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Magnetic hyperfine structure of the ground-state doublet in highly charged ions 229 The magnetic hyperfine (MHF) structure of the 5/2 + (0.0 eV) ground state and the low-lying 3/2 + (7.8 eV) isomeric state of the 229 Th nucleus in highly charged ions Th 89+ and Th 87+ is calculated. The distribution of the nuclear magnetization (the Bohr-Weisskopf effect) is accounted for in the framework of the collective nuclear model with the wave functions of the Nilsson model for the unpaired neutron. The deviations of the MHF structure for the ground and isomeric states from their values in the model of point-like nuclear magnetic dipole are calculated. The influence of the mixing of the states with the same quantum number F on the energy of sublevels is studied. Taking into account the mixing of states, the probabilities of the transitions between the components of MHF structure are found.

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Erratum: Radiative lifetime and energy of the low-energy isomeric level in 229Th [Phys. Rev. C 92 , 054324 (2015)]

Abstract: Erratum: Radiative lifetime and energy of the low-energy isomeric level in 229 Th[Phys. Rev. C 92, 054324 (2015)]

Cited by 38 publications

References 6 publications

A Laser Excitation Scheme for Th229m

A Laser Excitation Scheme for Th229m

Synthetic frequency protocol for Ramsey spectroscopy of clock transitions

Magnetic hyperfine structure of the ground-state doublet in highly charged ionsTh89+,87+229and the Bohr-Weisskopf effect

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