Spectroscopic studies of neutron-rich ¹²⁹In and its $\beta$ -decay daughter, ¹²⁹Sn, using the GRIFFIN spectrometer

F.H. Garcia fatimag@sfu.ca Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada C. Andreoiu Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada G.C. Ball TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada N. Bernier Present address: Department of Physics, University of the Western Cape, P/B X17, Bellvill, ZA-7535, South Africa TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada H. Bidaman Department of Physics, University of Guelph, Guelph, Ontario N1G 2W1, Canada V. Bildstein Department of Physics, University of Guelph, Guelph, Ontario N1G 2W1, Canada M. Bowry Present address: School of Computing, Engineering and Physical Sciences, University of the West of Scotland, Paisley PA1 2BE, United Kingdom TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada D.S. Cross Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada M.R. Dunlop Department of Physics, University of Guelph, Guelph, Ontario N1G 2W1, Canada R. Dunlop Department of Physics, University of Guelph, Guelph, Ontario N1G 2W1, Canada A.B. Garnsworthy TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada P.E. Garrett Department of Physics, University of Guelph, Guelph, Ontario N1G 2W1, Canada J. Henderson Present address: Lawrence Livermore National Laboratory, Livermore, California 94550, USA TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada J. Measures TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada University of Surrey, Guildford GU2 7XH, United Kingdom B. Olaizola TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada K. Ortner Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada J. Park Present address: Department of Physics, Lund University, 22100 Lund, Sweden TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada C.M. Petrache Centre de Sciences Nucléaire et Sciences de la Matière, CNRS/IN2P3, Université Paris-Saclay, Orsay, France J.L. Pore Present address: Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada K. Raymond Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada J.K. Smith Present Address: Department of Physics, Pierce College, Puyallup, Washington 98374, USA TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada D. Southall Present address: Department of Physics, University of Chicago, Chicago, IL 60637, USA TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada C.E. Svensson Department of Physics, University of Guelph, Guelph, Ontario N1G 2W1, Canada M. Ticu Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada J. Turko Department of Physics, University of Guelph, Guelph, Ontario N1G 2W1, Canada K. Whitmore Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada T. Zidar Department of Physics, University of Guelph, Guelph, Ontario N1G 2W1, Canada

(September 19, 2025)

Abstract

The $\beta$ -decay of neutron-rich ¹²⁹In into ¹²⁹Sn was studied using the GRIFFIN spectrometer at the ISAC facility at TRIUMF. The study observed the half-lives of the ground state and each of the $\beta$ -decaying isomers. The level scheme of ¹²⁹Sn has been expanded with thirty-one new $\gamma$ -ray transitions and nine new excited levels, leading to a re-evaluation of the $\beta$ -branching ratios and level spin assignments. The observation of the $\beta$ -decay of the (29/2⁺) 1911-keV isomeric state in ¹²⁹In is reported for the first time, with a branching ratio of 2.0(5) $\%$ .

pacs:

Valid PACS appear here

I Introduction

The region around the doubly magic ${}^{132}_{\texttt{ }50}$ Sn₈₂ nucleus is replete with critical information required for nuclear structure models and astrophysical applications [1, 2]. This isotope region is a key input to the nuclear shell model and the theoretical frameworks required to establish a working predictive and descriptive model of nuclei, and as a result it has been the focus of a series of theoretical studies [3, 4, 5].

In nuclear astrophysics there is also a need for information on this region due to the importance of the $A=130$ elemental abundance peak [6, 7]. The rapid neutron-capture process (r-process) is responsible for the generation of isotopes heavier than iron in stellar environments [8, 9], and is shown to have key waiting points at the magic shell closures in the vicinity of the tin isotopes [10, 11].

The ¹²⁹Sn nucleus, three neutrons removed from the $N=82$ shell closure, is important for studying the effects of single neutron excitations and other shell effects, as evidenced by the sixty years of study it has undergone. Several production mechanisms have been used in order to study ¹²⁹In, and its $\beta^{-}$ daughter, ¹²⁹Sn, including fission [12], $\beta^{-}$ -decay [13, 14, 15, 16, 17], $\beta$ n-decay [18, 19] and internal transition decay [20, 21]. Though the information on the transitions and energy levels in this daughter nucleus is plentiful, there are virtually no definitive spin or parity assignments for the levels above the 3/2⁺ ground state, the 11/2^- 35-keV isomer and the (1/2)⁺ 315-keV excited state.

In order to study and increase the available information on this key nucleus, ¹²⁹Sn, high-efficiency $\gamma$ -ray spectroscopy and coincidence techniques were used to uncover new transitions, new decay patterns and new levels, providing more input information for state-of-the-art theoretical models.

II Experiment

The Isotope Separator and ACcelerator (ISAC) facility of TRIUMF [22] employs the Isotope Separation On-Line (ISOL) technique in order to produce radioactive isotope beams [23]. Isotopes are generated by bombarding a uranium carbide (UC_x) target with a 9.8 $\mu$ A beam of 480 MeV protons, provided by the main 520-MeV cyclotron [24]. The relevant isotopes are selectively ionized for extraction using the Ion-Guide Laser Ion Source (IGLIS) [25], in order to reduce any isobaric contamination. The ionized species are then passed through the high-resolution mass spectrometer ( $M/\delta M\sim 2000$ ) [26], in order to produce an isotopically clean beam. Once extracted, the desired ¹²⁹In radioactive isotope beam is transported to the experimental station. The $\beta^{-}$ decay of the ¹²⁹In isotope to ¹²⁹Sn was observed using the Gamma-Ray Infrastructure For Fundamental Investigations of Nuclei (GRIFFIN) [27, 28, 29]
The GRIFFIN array is a state-of-the-art, high-resolution $\gamma$ -ray spectrometer, equipped with sixteen high-purity germanium (HPGe) clover detectors for the identification of $\gamma$ -rays [30]. Each of the sixteen HPGe clover detectors contains four crystals, making a total of 64 crystals that can detect $\gamma$ -rays, allowing for analyses to be carried out in single crystal or addback modes [28, 30]. For this experiment, the SCintillating Electron-Positron Tagging ARray (SCEPTAR) [28] was placed at the centre of GRIFFIN, in order to provide tagging for $\beta$ particles. A cycling mylar tape station, the focus of which is at the centre of SCEPTAR, provides a continuous implantation spot and aids in the removal of contaminants. An implantation cycle can be set to optimize observation of the decay of interest. During the course of this experiment, a mix of the $\beta^{-}$ decaying isomers of ¹²⁹In were implanted at a rate of $\sim$ 5000 particles per second, with a beam composition of approximately 41% in the 9/2⁺ ground state, ¹²⁹In^gs, 54% in the (1/2^-) 459-keV ¹²⁹In^m1 isomer, 3% in the (23/2^-) 1630-keV ¹²⁹In^m2 isomer and 1% in the (29/2⁺) 1911-keV ¹²⁹In^m3 isomer, neglecting the uncertainty in the ground state branch of the (1/2^-) isomer.
The GRIFFIN array was arranged in its high-efficiency configuration, where the HPGe clover detectors were positioned 11 cm away from the implantation spot [28]. A 20 mm Delrin shield was put in place around SCEPTAR to minimize Bremsstrahlung radiation from high energy $\beta^{-}$ particles. The experimental campaign for ¹²⁹In consisted of running the tape system in consecutive 21.5-second cycles, with 1.5 s for tape move, 5 s for background collection, 10 s for isotope implantation and 5 s for isotope decay. The total run duration was 2.75 hrs, for a total of 460 cycles with 6.29 $\times 10^{7}$ addback singles events, and 1.81 $\times 10^{7}$ coincidence events collected during the run time. The combination of GRIFFIN and SCEPTAR allowed for the correlated observation of $\gamma$ -rays in coincidence with the emitted $\beta$ particles, in a 500 ns coincidence window, in order to tag on the specific ¹²⁹In decays. Furthermore, $\gamma$ - $\gamma$ coincidences, with a 500 ns coincidence window, were used for the verification of transitions and decay patterns through the excited levels of the ¹²⁹Sn daughter.
The energy and efficiency calibrations for GRIFFIN were done using a series of standard sources of ⁵⁶Co, ⁶⁰Co, ¹³³Ba, ¹⁵²Eu, allowing for a calibration to be made in the range between 81 keV and 3.6 MeV. Coincidence summing corrections were done by constructing a $\gamma$ - $\gamma$ matrix with detectors positioned at 180^∘ of each other to correct for real coincidence summing, a methodology established for GRIFFIN in Ref. [29]. Transitions were also verified to be real transitions rather than sum or escape peaks.

III Results

III.1 Transitions and Levels in ¹²⁹Sn

Refer to caption — Figure 1: $\beta$ -gated $\gamma$ -ray spectrum, in addback mode, showing various known transitions in ¹²⁹Sn (red squares). Transitions in ¹²⁹Sb ( $\beta$ decay daughter of ¹²⁹Sn; green circles) and ¹²⁸Sn ( $\beta$ n daugther of ¹²⁹In; blue triangles) are also observed.

The $Q_{\beta}$ value for the ¹²⁹In $\beta$ -decay to ¹²⁹Sn is 7.769(19) MeV and the neutron separation energy, $S_{n}$ , for ¹²⁹Sn is 5.316(26) MeV [31]. Gamma-ray transitions were investigated up to the neutron separation energy. From the analysis of this data set, all but two of the transitions currently reported for the ¹²⁹Sn nucleus were observed [31]. There were also 31 newly observed transitions and 9 newly observed excited states in the ¹²⁹Sn nucleus, never observed through the $\beta^{-}$ decay of its ¹²⁹In parent or otherwise. Figure 1 shows a portion of the $\beta$ -gated $\gamma$ -ray spectrum observed in this work; transitions in the ¹²⁹Sn of interest, along with transitions in the $\beta$ granddaughter, ¹²⁹Sb, and in the ¹²⁹In $\beta$ n daughter, ¹²⁸Sn are identified. Figures 2 and 3 demonstrate the mechanism used to establish new transitions. Figure 2 shows the gating from below method used to determine several intensities, in this case that of the 1071-keV transition. The intensity of this transition required gating from below on the 1047-keV transition, while Figure 3 shows the $\gamma$ -ray spectrum resulting from a gate placed on the 1054-keV transition, where coincident transitions at 1257, 1271 and 1302 keV were observed.

Table LABEL:tab:gammaTable summarizes the energy levels observed in this work, along with the transitions from each level, the final state, the relative intensity with respect to the highest intensity 2118-keV $\gamma$ -ray, and the $\gamma$ -ray branching ratio. The table also compares the branching ratios for each of the known $\gamma$ -rays appearing in the evaluation by Timar, Elekes and Singh [31]. With the exception of seven $\gamma$ -rays at 146, 278, 280, 1071, 1096, 1586, and 2371 keV, all transition intensities were obtained from the addback singles spectrum. The seven $\gamma$ -rays mentioned required directly gating from below in order to fit their energy and intensity values, as demonstrated in Figure 2. The other new transitions were observed in the $\gamma$ -ray spectrum and their placement confirmed through coincidence gating, as in shown in Figure 3.

Though most of the branching ratios observed in the course of this work are in good agreement with the work of Gausemel et al. [17], there are some notable discrepancies. These are attributed to major differences in the conditions of the two experiments. The work by Gausemel et al. utilized three germanium detectors, while the present work made use of all 16 HPGe clover detectors available to the GRIFFIN array, allowing for more efficient coincidence detection. Furthermore, some of the transitions were observed with branching ratios down to $10^{-4}$ , pushing the limits of the detection mechanisms available to the previous experiment. The $\beta$ -decay of the (29/2⁺) 1911-keV isomer in ¹²⁹In to the (27/2^-) 2552-keV state in ¹²⁹Sn was observed for the first time. This 2552-keV state was previously observed in the fission study done by Lozeva et al. [21]. The transitions from the isomeric states at 1762 keV and 1803 keV to lower-lying states in the level scheme, 19.7 keV and 41.0 keV, respectively, were not observed. However transitions feeding into these states were present in the data, confirming the placement of the levels, within uncertainty.

{ThreePartTable}{TableNotes}

new spin assignment

Table 1: Energy levels and transitions observed in ¹²⁹Sn, following the

\beta^{-}

decay of ¹²⁹In. All intensities are normalized to the most intense transition at 2118 keV, from the (7/2⁺) 2118-keV state to the 3/2⁺ ground state. The values calculated in this experiment are compared to those present in the Evaluated Nuclear Structure Data File search (ENSDF) database of the National Nuclear Data Center (NNDC). The level spins and parities are adopted from Ref. [31], unless otherwise stated.

This work							ENSDF
$E$ level (keV)	$E_{\gamma}$ (keV)	$J^{\pi}_{i}$	$J^{\pi}_{f}$	$E_{f}$ (keV)	Relative $I_{\gamma}$	$BR_{\gamma}$	$BR_{\gamma}$
0		3/2⁺
35.2(2)		11/2^-
315.1(2)	315.4(2)	(1/2⁺)	3/2⁺	0	0.611(5)	100	100
763.7(1)	728.5(2)	(9/2^-)	11/2^-	35.2(2)	0.163(2)	100	100
769.1(1)	769.3(2)	(5/2⁺)	3/2⁺	0	0.297(3)	100	100
1043.9(1)	280.4(2)^†	(7/2^-)	(9/2^-)	763.7(1)	0.0068(8)	3.6(5)	4.3(6)
	1008.5(2)	(7/2^-)	11/2^-	35.2(2)	0.186(2)	100(1)	100
1047.0(2)	278.0(2)^†	(7/2⁺)	(5/2⁺)	769.1(1)	0.0080(10)	95(7)	68(16)
	1047.4(2)	(7/2⁺)	3/2⁺	0	0.0086(4)	100(5)	100(8)
1054.3(2)	285.2(2)	(7/2⁺)	(5/2⁺)	769.1(1)	0.036(2)	34(1)	33(2)
	1054.4(2)	(7/2⁺)	3/2⁺	0	0.1050(10)	100.0(5)	100(7)
1171.5(3)	1136.4(2)	(15/2^-)	11/2^-	35.2(2)	0.1698(14)	100	100(7)
1222.4(2)	175.5(4)	(3/2⁺)	(7/2⁺)	1047.0(2)	0.0025(6)	5(1)	2.2(13)
	907.3(2)	(3/2⁺)	(1/2⁺)	315.1(2)	0.0394(7)	86(1)	74(5)
	1222.6(2)	(3/2⁺)	3/2⁺	0	0.0461(5)	100.0(9)	100(7)
1288.6(2)	519.5(7)	(3/2⁺)	(5/2⁺)	769.1(1)	0.007(3)	32(14)	36(6)^§
	973.6(2)	(3/2⁺)	(1/2⁺)	315.1(2)	0.0193(9)	88(4)	80(5)^§
	1288.8(2)	(3/2⁺)	3/2⁺	0	0.0220(4)	100(2)	100(6)^§
1359.5(3)	1324.4(2)	(13/2^-)	11/2^-	35.2(2)	0.1306(13)	100	100
1455.2(2)	1455.0(2)	(5/2⁺)	3/2⁺	0	0.0306(9)	100	100
1534.4(2)	480.2(2)	(7/2^-, 9/2⁺)	(7/2⁺)	1054.3(2)	0.0137(11)	100(8)	100(9)
	765.0(3)	(7/2^-, 9/2⁺)	(5/2⁺)	769.1(1)	0.0037(11)	27(8)	69(6)
	1499.1(2)	(7/2^-, 9/2⁺)	11/2^-	35.2(2)	0.0114(7)	84(5)	99(7)
1607.3(3)	553.1(3)	(7/2 – 11/2)^∗	(7/2⁺)	1054.3(2)	0.0037(6)	58(9)
	843.4(3)	(7/2 – 11/2)^∗	(7/2⁺)	763.7(1)	0.0064(5)	100(7)
1613.6(3)	1613.4(2)	(7/2⁺)^‡	3/2⁺	0	0.0359(5)	100	100(6)
1688.3(3)	919.0(3)	(7/2^-, 9/2⁺)^∗	(5/2⁺)	769.1(1)	0.0027(2)	100(9)
	1653.0(3)	(7/2^-, 9/2⁺)^∗	11/2^-	35.2(2)	0.0025(3)	92(12)
1701.0(2)	657.3(2)	(7/2^-)	(7/2^-)	1043.9(1)	0.0043(3)	45(4)	75(6)^§
	932.0(2)	(7/2^-)	(5/2⁺)	769.1(1)	0.0094(4)	100(4)	100(9)^§
	937.4(2)	(7/2^-)	(9/2^-)	763.7(1)	0.0075(5)	79(6)	95(9)^§
	1665.6(3)	(7/2^-)	11/2^-	35.2(2)	0.0027(7)	28(8)
1741.9(3)	382.4(2)	(15/2⁺)	(13/2^-)	1359.5(3)	0.1235(12)	77.2(6)	75(4)
	570.4(2)	(15/2⁺)	(15/2^-)	1171.5(3)	0.160(2)	100.0(7)	100(6)
1853.3(2)	318.0(6)	(7/2, 9/2)	(7/2^-, 9/2⁺)	1534.4(2)	0.0073(3)	48(2)	32(4)
	799.4(2)	(7/2, 9/2)	(7/2⁺)	1054.3(2)	0.0153(9)	100(6)	100(8)
	806.3(4)	(7/2, 9/2)	(7/2⁺)	1047.0(2)	0.0016(4)	11(3)
	1085.7(6)	(7/2, 9/2)	(5/2⁺)	769.1(1)	0.0046(3)	30(2)
1865.1(1)	330.9(3)	(7/2⁺)	(7/2^-, 9/2⁺)	1534.4(2)	0.0060(14)	0.7(2)	0.66(5)
	411.2(6)	(7/2⁺)	(5/2⁺)	1455.2(2)	0.0083(5)	1.03(6)	0.34(4)
	576.1(3)	(7/2⁺)	(3/2⁺)	1288.6(2)	0.0009(2)	0.11(3)	0.39(3)
	821.4(2)	(7/2⁺)	(7/2^-)	1043.9(1)	0.0173(5)	2.14(5)	2.22(1)
	1095.9(2)^†	(7/2⁺)	(5/2⁺)	769.1(1)	0.081(5)	9.9(6)	8.5(11)
	1101.4(2)	(7/2⁺)	(9/2^-)	763.7(1)	0.0435(7)	5.36(7)	5.7(4)
	1830.6(3)	(7/2⁺)	11/2^-	35.2(2)	0.0039(5)	0.48(6)	0.32(7)
	1864.8(2)	(7/2⁺)	3/2⁺	0	0.812(7)	100.0(6)	100(7)
1906.2(2)	1906.2(2)	(7/2)	3/2⁺	0	0.0093(4)	100	100
2023.6(4)	969.2(3)	(7/2 – 11/2)^∗	(7/2⁺)	1054.3(2)	0.0123(7)	100
2118.3(1)	212.2(3)	(7/2⁺)	(7/2)	1906.2(2)	0.0045(6)	0.45(6)	0.64(5)
	253.1(3)	(7/2⁺)	(7/2⁺)	1865.1(1)	0.0057(4)	0.57(4)	0.08(2)
	265.5(3)	(7/2⁺)	(7/2, 9/2)	1853.3(2)	0.0036(4)	0.36(4)	0.35(5)
	583.6(2)	(7/2⁺)	(7/2^-, 9/2⁺)	1534.4(2)	0.0144(7)	1.44(7)
	662.9(2)	(7/2⁺)	(5/2⁺)	1455.2(2)	0.0125(3)	1.25(3)	1.22(8)
	829.9(2)	(7/2⁺)	(3/2⁺)	1288.6(2)	0.0048(3)	0.48(3)	0.6(10)
	1071.0(2)^†	(7/2⁺)	(7/2⁺)	1047.0(2)	0.0006(1)	0.06(1)	0.2(10)
	1074.7(2)	(7/2⁺)	(7/2^-)	1043.9(1)	0.0666(7)	6.66(7)	6.1(4)
	1349.5(2)	(7/2⁺)	(5/2⁺)	769.1(1)	0.0511(8)	5.11(8)	4.6(3)
	1354.7(2)	(7/2⁺)	(9/2^-)	763.7(1)	0.0417(11)	4.2(1)	2.9(3)
	2083.0(3)	(7/2⁺)	11/2^-	35.2(2)	0.0033(4)	0.33(4)	0.42(4)
	2118.3(2)	(7/2⁺)	3/2⁺	0	1	100.0(6)	100(7)
2277(1)	474.0(2)	(21/2)	(23/2)⁺	1803(1)	0.0220(5)	100(2)	100(8)
	514.8(3)	(21/2)	(19/2)⁺	1762(1)	0.0081(6)	37(6)	30(3)
2326.1(4)	1270.5(6)	(7/2, 9/2⁺)^∗	(7/2⁺)	1054.3(2)	0.0012(3)	82(21)
	1558.1(4)	(7/2, 9/2⁺)^∗	(5/2⁺)	769.1(1)	0.0015(3)	100(18)
2406(1)	604.4(5)	(23/2^-)	(23/2⁺)	1803(1)	0.0090(4)	100	100
2552(1)	145.5(3)^†	(27/2^-)	(23/2^-)	2406(1)	0.0011(2)	100	100
2568.0(3)	2252.9(3)	(1/2, 3/2)^∗	(1/2)⁺	315.1(2)	0.0009(3)	93(30)
	2568.0(3)	(1/2, 3/2)^∗	3/2⁺	0	0.0010(6)	100(56)
2606.2(2)	1150.9(3)	(1/2, 3/2)^∗	(5/2⁺)	1455.2(2)	0.0002(2)	6(4)
	1384.2(3)	(1/2, 3/2)^∗	(3/2⁺)	1222.4(2)	0.0035(4)	90(11)
	2290.5(3)	(1/2, 3/2)^∗	(1/2)⁺	315.1(2)	0.0013(2)	33(6)
	2606.9(4)	(1/2, 3/2)^∗	3/2⁺	0	0.0039(4)	100(9)
2791.0(3)	1736.6(3)	(7/2, 9/2⁺)	(7/2⁺)	1054.3(2)	0.0018(3)	22(3)	36(24)
	2021.9(2)	(7/2, 9/2⁺)	(5/2⁺)	769.1(1)	0.0082(3)	100(3)	100(7)
2836.0(2)	718.0(3)	(7/2⁺, 9/2⁺)	(7/2⁺)	2118.3(1)	0.0026(5)	5(1)
	1301.8(2)	(7/2⁺, 9/2⁺)	(7/2^-, 9/2⁺)	1534.4(2)	0.0058(8)	12(2)	10.2(8)
	1781.4(2)	(7/2⁺, 9/2⁺)	(7/2⁺)	1054.3(2)	0.0490(6)	100(1)	100(7)
	1791.4(3)	(7/2⁺, 9/2⁺)	(7/2^-)	1043.9(1)	0.0031(4)	6.3(7)	7.2(7)
	2066.5(2)	(7/2⁺, 9/2⁺)	(5/2⁺)	769.1(1)	0.0299(6)	61(1)	57(4)
	2072.9(3)	(7/2⁺, 9/2⁺)	(9/2^-)	763.7(1)	0.0003(1)	0.6(2)	3.5(9)
2981.9(2)	863.8(4)	(7/2⁺)	(7/2⁺)	2118.3(1)	0.0007(3)	3(1)
	1128.7(2)	(7/2⁺)	(7/2, 9/2)	1853.3(2)	0.0036(8)	18(4)
	1927.6(3)	(7/2⁺)	(7/2^-)	1054.3(2)	0.0015(3)	8(1)
	2212.6(2)	(7/2⁺)	(5/2⁺)	769.1(1)	0.0201(5)	100(2)	100(6)
	2980.7(7)	(7/2⁺)	3/2⁺	0	0.0009(2)	4.5(8)	9.2(18)
3079.3(3)	2035.6(3)	(3/2^-)	(7/2^-)	1043.9(1)	0.0045(7)	79(11)	90(9)
	2764.0(2)	(3/2^-)	(1/2)⁺	315.1(2)	0.0057(3)	100(5)	100(8)
3140.3(2)	1526.1(3)	(7/2⁺)	(7/2⁺)	1613.6(3)	0.0020(5)	17(4)
	2094.0(3)	(7/2⁺)	(7/2⁺)	1047.0(2)	0.0041(4)	34(3)
	2371.1(3)^†	(7/2⁺)	(5/2⁺)	769.1(1)	0.0045(3)	37(3)	16.2(18)
	2376.4(3)	(7/2⁺)	(9/2^-)	763.7(1)	0.0025(6)	20(5)	30(3)
	3140.1(2)	(7/2⁺)	3/2⁺	0	0.0123(3)	100(2)	100(8)
3393.9(4)	3078.7(3)	(1/2, 3/2)	(1/2)⁺	315.1(2)	0.0077(3)	100	100
3446.7(4)	2683.0(3)	(7/2 – 11/2)^∗	(9/2^-)	763.7(1)	0.0005(2)	100
3581.8(3)	1257.0(6)	(7/2, 9/2⁺)^∗	(7/2, 9/2)	2326.1(4)	0.0013(2)	90(17)
	2527.1(3)	(7/2, 9/2⁺)^∗	(7/2⁺)	1054.3(2)	0.0013(3)	93(23)
	2812.7(8)	(7/2, 9/2⁺)^∗	(5/2⁺)	769.1(1)	0.0014(4)	100(25)
	2818.4(5)	(7/2, 9/2⁺)^∗	(9/2^-)	763.7(1)	0.0010(4)	69(27)
3590.4(1)	1889.5(2)	(3/2^-)	(7/2^-)	1701.0(2)	0.0106(5)	23(1)	23(2)
	1977.0(2)	(3/2^-)	(7/2⁺)	1613.6(3)	0.0113(5)	24(1)	21(2)
	2301.7(2)	(3/2^-)	(3/2⁺)	1288.6(2)	0.0178(3)	38.0(5)	30(2)
	2367.9(2)	(3/2^-)	(3/2⁺)	1222.4(2)	0.0292(4)	62.3(7)	51(4)
	2546.2(2)	(3/2^-)	(7/2^-)	1043.9(1)	0.0469(5)	100(1)	100(7)
	3276.0(2)	(3/2^-)	(1/2)⁺	315.1(2)	0.0440(6)	94(1)	63(4)
	3589.7(3)	(3/2^-)	3/2⁺	0	0.0058(5)	12(1)	12.6(11)
3993(1)	1586.3(3)^†	(21/2^-)	(23/2^-)	2406(1)	0.011(6)	7.2(1)
	1715.9(2)	(21/2^-)	(21/2)	2277(1)	0.0286(7)	17.6(4)	16.4(14)
	2189.8(2)	(21/2^-)	(23/2⁺)	1803(1)	0.162(2)	100.0(7)	100(7)
	2230.8(2)	(21/2^-)	(19/2⁺)	1762(1)	0.0577(9)	35.5(5)	41(2)
4136.6(3)	2847.8(2)	(1/2, 3/2)^∗	(3/2⁺)	1288.6(2)	0.0026(1)	100(3)
	2915.5(5)	(1/2, 3/2)^∗	(3/2⁺)	1222.4(2)	0.0019(3)	73(12)
^∗ Spin assignment for new levels, based on $\beta$ and $\gamma$ decay systematics.
^† Intensity calculated from coincidences.
^‡ Revised spin assignment for known levels, based on $\beta$ and $\gamma$ decay systematics.
^§ Based on ENSDF information: Weighted average between ¹²⁹In^gs and ¹²⁹In^m1.

Table 1: (Continued).

III.2 Decay of the 9/2⁺ ${}^{129}\textrm{In}$ ground state

III.2.1 Half-life of ¹²⁹In^gs

Plotting the intensity of a $\gamma$ -ray as a function of cycle time allows for the measurement of isotope half-life; a spectrum can be generated and fit with a characteristic decay formula, from which the half-life can then be extracted. To improve statistics, background-corrected timing gates on 39 $\gamma$ -rays — shown in Table 2 — associated with the decay of the ¹²⁹In ground state into ¹²⁹Sn were summed and the counts as a function of cycle time fit using a standard exponential decay, as seen in Figure 4. The fit returned a half-life of $t_{1/2}=0.60(1)$ s, in agreement with $t_{1/2}=0.611(5)$ s quoted in the evaluation by Timar, Elekes and Singh [31]. A chop analysis, which involved a change in the width of the timing window for the fit, was conducted to check for any rate dependent effects on the half-life; no discernible effects were observed. The weighted average value between the evaluted half-life of 0.611(5) s and the observed half-live of 0.60(1) s is calculated to be 0.609(4) s, where the uncertainty has been increase by the $\sqrt{\chi^{2}}$ .

Table 2: Transitions used to build the half-life plot shown in Figure 4. These were identified as transitions from states populated by the ground state of ¹²⁹In.

Transitions (keV)
212.2(3)	662.9(2)	1349.5(2)	2021.9(2)
253.1(3)	765.0(3)	1354.7(2)	2066.5(2)
265.5(3)	799.4(2)	1499.1(2)	2072.9(3)
278.0(2)	821.4(2)	1613.4(2)	2083.0(3)
285.2(2)	829.9(2)	1736.6(3)	2118.3(2)
318.0(6)	1054.4(2)	1781.4(2)	2212.6(2)
330.9(3)	1074.7(2)	1791.4(3)	2376.4(3)
411.2(6)	1095.9(2)	1830.6(3)	2980.7(7)
480.2(2)	1101.4(2)	1864.8(2)	3140.1(2)
576.1(3)	1301.8(2)	1906.2(2)

III.2.2 $\beta$ -feeding and logft values

Several new transitions and new levels from the $\beta$ -decay of the ground state of ¹²⁹In into excited states of ¹²⁹Sn were observed. Figure 5 shows the $\gamma$ -rays observed in ¹²⁹Sn due to this decay. Newly observed transitions and levels are coloured (red), along with their proposed spin assignments.

Table 3 lists the states that are populated by the ground state along with the $\beta$ -feeding intensities and the logft values calculated in this work, together with a comparison to the work of Gausemel et al. [17]. The electron conversion coefficients for low-energy $\gamma$ -rays are taken into account when doing these calculations, using the BrIcc utility available through the NNDC [32]. The data observed by Gausemel et al. showed direct $\beta$ -feeding to the 35-keV isomeric state on the order of $<10\%$ . The $\beta$ -feeding values obtained in the present work are normalized to reflect 100 $\%$ feeding to excited states.

Spin assignments for the newly observed levels are proposed based on the $\beta$ -decay selection rules and $\gamma$ -ray systematics. The newly observed states at 1607 keV, 2024 keV and 3447 keV are tentatively assigned spins between (7/2) and (11/2), as they are observed to decay to states with proposed spins between 7/2 and 9/2, while decays to states with spins of 3/2 or lower were not observed.

The new state at 1688 keV decays to the 11/2^- 35-keV and (5/2⁺) 769-keV levels such that the spin and parity of this state can be restricted to (7/2^-, 9/2⁺). The new states at 2326 keV and 3582 keV are observed to decay to states with tentative spins between (5/2⁺) and 9/2^-, such that their spins can be restricted to (7/2, 9/2⁺). The logft values calculated between the (9/2⁺) ¹²⁹In^gs and the above mentioned states, shown in Table 3, are all consistent with the allowed or first-forbidden decays implied by the proposed spin assignments.

Table 3: The

\beta

-feeding intensities and logft values for states in ¹²⁹Sn, observed through the

\beta

-decay of the (9/2⁺) ¹²⁹In^gs state and calculated with the weighted average half-life of 0.609(4) s. Columns denoted by Ref. [17] contain values established in the work of Gausemel et al.. The

\beta

-feeding values have been normalized to reflect 100% feeding of excited states.

$E_{x}$ (keV)	$I_{\beta}$ (%)		logft
$E_{x}$ (keV)	This work	Ref. [17]	This work	Ref. [17]
763.7(1)	2.03(8)	2.1(4)	6.43(2)	6.4(1)
1043.9(1)	1.95(8)	2.0(4)	6.36(2)	6.4(1)
1047.0(2)	0.30(4)	0.35(6)	7.17(6)	7.1(1)
1054.3(2)	1.62(10)	2.1(3)	6.44(3)	6.33(7)
1534.4(2)	0.60(9)	0.46(6)	6.73(7)	6.85(6)
1607.3(3)	0.14(2)		7.33(7)
1613.6(3)	0.88(3)		6.54(2)
1688.2(3)	0.20(2)		7.15(4)
1701.0(2)	0.52(5)	0.24(2)	6.74(5)	7.08(4)
1853.3(2)	0.85(5)	0.76(6)	6.47(3)	6.53(4)
1865.1(1)	37.6(3)	36(2)	4.83(1)	4.85(3)
1906.2(2)	0.18(3)	0.13(3)	7.13(8)	7.3(1)
2023.6(4)	0.48(3)		6.67(3)
2118.3(1)	46.9(3)	49(3)	4.64(1)	4.63(3)
2326.1(4)	0.06(2)		7.49(14)
2791.0(3)	0.39(15)	0.47(9)	6.48(2)	6.4(1)
2836.0(2)	3.53(5)	3.36(15)	5.51(1)	5.54(2)
2981.9(2)	1.01(4)	0.74(5)	5.99(2)	6.14(3)
3140.3(2)	0.99(4)	0.67(4)	5.94(2)	6.11(3)
3446.7(4)	0.020(9)		7.5(2)
3581.8(3)	0.19(3)		6.46(7)

Previous work using $\gamma$ -ray information [17, 31] assigned a spin of between (1/2) and (7/2⁺) for the 1614-keV level, with no detectable $\beta$ -feeding from the (1/2^-) ¹²⁹In^m1 parent. Gausemel et al. observed a transition at 1977 keV, from the (3/2^-) 3590-keV state to the 1614-keV state, which was observed in the present work and is shown in Figure 7. A new transition, at 1526-keV, was also observed from the (7/2⁺) state at 3140 keV, casting doubt on the possibility of a 1/2 spin. Furthermore, the 1614-keV level is observed to have a direct $\beta$ -feeding component, equivalent to double the intensity of the 1977-keV transition from the 3590-keV state observed both by Gausemel et al. and in this work, indicating that the 1614-keV level is most likely fed by the (9/2⁺) ¹²⁹In^gs and has a spin of (7/2⁺). This spin assignment is corroborated by the 6.54(2) logft value shown in Table 3, which is consistent with an allowed transition.

III.3 Decay of (1/2^-) ${}^{129}\textrm{In}^{m1}$

III.3.1 Half-life of ¹²⁹In^m1

The twelve $\gamma$ -ray transitions used to generate the half-life spectrum shown in Figure 6 are listed in Table 4. The fit to the data returned a half-life of $t_{1/2}=1.16(1)$ s. A chop analysis was carried out and no systematic effects were observed. The present result is a factor of three more precise than the value 1.23(3) s quoted in the evaluation by Timar, Elekes and Singh [31]. The weighted average of these two values is 1.17(2) s, with its uncertainty increased by $\sqrt{\chi^{2}}$ .

Table 4: Transitions used to build the half-life plot shown in Figure 6. These were identified as transitions from states populated by the

{}^{129}In^{m1}

isomer.

Transitions (keV)
175.5(4)	1889.5(2)	2764.0(2)
315.4(2)	2035.6(3)	3078.7(3)
907.3(2)	2367.9(2)	3276.0(2)
1222.6(2)	2546.2(2)	3589.7(3)

III.3.2 $\beta$ -feeding and logft values

The ¹²⁹In^m1 isomer was observed to decay to known states in ¹²⁹Sn, as well as to three newly observed states. Figure 7 shows the $\gamma$ -rays observed in this decay; the spins of the three new levels populated in ¹²⁹Sn were determined from $\beta$ -feeding and $\gamma$ -ray systematics. Table 5 summarizes the $\beta$ -feeding intensities and the logft values obtained in the present work, using the weighted half-life value of 1.17(2) s, compared with the results of Gausemel et al. [17] who also observed a 77(15) $\%$ direct $\beta$ -feeding to the 3/2⁺ ground state in ¹²⁹Sn; the present $\beta$ -feeding intensities have been scaled to represent the remaining 23 $\%$ of observed $\beta$ -feeding to excited states.

The new states at 2568 keV and 2606 keV are observed to decay to the (1/2)⁺ 315-keV state; therefore they are likely to have a spin of either 1/2 or 3/2, and be fed by the (1/2^-) ¹²⁹In^m1. The 4137-keV state decays to the 1289-keV and 1222-keV states, both of which have tentative spin assignments of (3/2⁺), indicating that this state is likely to have a 1/2 or 3/2 spin. The logft values for these states, shown in Table 5, are consistent with either the allowed or first-forbidden transitions expected from the (1/2^-) ¹²⁹In^m1 to the respective states in ¹²⁹Sn.

Table 5: The

\beta

-feeding intensities and logft values, calculated, for states in ¹²⁹Sn, observed through the

\beta

-decay of the (1/2^-) ¹²⁹In^m1 isomer and calculated with the weighted average half-life of 1.17(2) s. The values calculated in this work are compared to the values calculated by Gausemel et al. [17].

^† Unique 1st forbidden
$E_{x}$ (keV)	$I_{\beta}$ (%)		logft
$E_{x}$ (keV)	This work	Ref. [17]	This work	Ref. [17]
315.1(2)	14.3(2)	15.1(13)	6.10(1)	6.10(4)
769.1(1) ^†	0.9(2)		9.31(9)
1222.4(2)	1.52(4)	1.56(14)	6.83(2)	6.85(4)
1288.6(2)	0.63(9)	0.58(7)	7.20(7)	7.26(6)
1455.2(2) ^†	0.28(3)		9.55(5)
2568.0(3)	0.06(2)		7.86(15)
2606.2(2)	0.25(2)		7.19(4)
3079.3(3)	0.29(2)	0.42(3)	6.96(4)	6.82(4)
3393.9(4)	0.219(8)	0.22(2)	6.96(2)	6.98(5)
3590.4(1)	4.70(6)	5.10(17)	5.55(1)	5.54(2)
4136.6(3)	0.127(9)		6.88(4)

The excess feeding into the (5/2⁺) states at 769 keV and 1455 keV has been attributed to direct $\beta$ -feeding from the (1/2^-) ¹²⁹In^m1 to these states, rather than to unobserved transitions feeding these levels from higher levels populated by either the $\beta$ -decay of the (9/2⁺) ¹²⁹In^gs or the (1/2^-) ¹²⁹In^m1. The logft values for the 769-keV and 1455-keV states, calculated with feeding from ¹²⁹In^m1 are 9.31(9) and 9.55(5), respectively, consistent with unique first-forbidden transitions, supporting the spin assignments for these states, given as (5/2⁺).

III.4 Decay of (23/2^-) ${}^{129}\textrm{In}^{m2}$

III.4.1 Half-life of ¹²⁹In^m2

Only four viable $\gamma$ -ray transitions, at 382, 515, 2190 and 2231 keV, could be used in the half-life fitting of the ¹²⁹In^m2 isomer. The spectrum and the fit are show in Figure 8. The adopted value for the half-life of the (23/2^-) ¹²⁹In^m2 is $t_{1/2}=0.65(2)$ s. This result, which includes a systematic uncertainty associated with the chop analysis, has an error of a factor of five times smaller than the established value, quoted by Timar, Elekes and Singh [31], as $t_{1/2}=0.67(10)$ s. The weighted average between the half-life in the evalution and the half-life observed in this work is 0.65(2) s, with the uncertainty increased by $\sqrt{\chi^{2}}$ .

III.4.2 $\beta$ -feeding and logft values

The level scheme associated with the $\beta$ -decay of the ¹²⁹In^m2 is shown in Figure 9. Table 6 shows the $\beta$ feeding intensities and logft values obtained in this work, along with a comparison to those observed by Gausemel et al.[17]. One new transition was observed in the present work. The branching ratios measured for the decay of the 3993-keV (21/2^-) level to the 1762-, 1803- and 2277-keV levels and for the decay of the 2277-keV level to the 1762- and 1803-keV levels are in reasonable agreement with previous data [17], as seen in Table LABEL:tab:gammaTable. However, the $\beta$ feeding intensity of the 2277-keV level is nearly a factor of ten smaller than the value previously observed.

Direct $\beta$ -feeding to the 1803-keV level was estimated based on the intensities of the $\gamma$ -rays populating this state and the $\gamma$ -ray intensities depopulating states below, connected through two transitions, a 41.0(2)-keV transition from the 1803-keV state to the 1762-keV state, and a 19.7(10)-keV transition from the 1762-keV state to the 1742-keV state. A direct $\beta$ -feeding of 10(4) $\%$ to the 1803-keV state was observed, consistent with the previously reported value of 14(4) $\%$ $\beta$ -feeding intensity observed previously [17]. Table 6 also summarizes the $\beta$ -feeding intensities and the logft values for the 2277-keV and 3993-keV states.

Table 6: The

\beta

-feeding intensities and logft values, calculated for states in ¹²⁹Sn, observed through the

\beta

-decay of the (23/2^-) ¹²⁹In^m2 isomer and calculated with the weighted average half-life of 0.65(2) s. The values are calculated in this work are compared to those calculated by Gausemel et al. [17].

$E_{x}$ (keV)	$I_{\beta}$ (%)		logft
$E_{x}$ (keV)	This work	Ref. [17]	This work	Ref. [17]
1803(1)	10(4)	14(4)	5.92(18)	5.8(2)
2277(1)	0.5(3)	8.0(12)	7.1(3)	5.9(1)
3993(1)	89(4)	75(4)	4.31(2)	4.4(1)

III.5 Decay of (29/2⁺) ${}^{129}\textrm{In}^{m3}$

Above the 1630-keV isomer in ¹²⁹In, there is another isomer at 1911 keV with spin (29/2⁺). This state has been shown to decay through a 281-keV internal transition to the 1630-keV ¹²⁹In^m2 isomer. This transition lies very close in energy to two known transitions in the ¹²⁹Sn nucleus, at 278.0(2)-keV and 280.4(2)-keV, which depopulate the 1047-keV and 1044-keV states, respectively, as seen in Figure 5.

The total relative intensity obtained in the addback singles $\gamma$ -ray spectrum was 0.0805(4) for the triplet centered around 280-keV. This was inconsistent with the measured intensity of either the 278-keV and 280-keV transitions, observed in previous studies [17], and therefore the intensities of the transitions were measured by gating from below, on the 769-keV transition depopulating the 769-keV state for the transition at 278-keV, and the 728-keV transition that depopulates the 764-keV state for the 280-keV transition.

The relative intensity of the 278-keV transition was found to be 0.0080(10), consistent with previous measurements of both $\gamma$ -ray intensity and the $\beta$ -feeding of the 1047-keV state. Similarly, the relative intensity of the 280-keV transition in ¹²⁹Sn was measured to be 0.0068(8), in agreement with the previously measured $\gamma$ -ray intensity and $\beta$ -feeding to the 1044-keV state. The remaining intensity at 281-keV, amounting to 0.0657(11), must then be due to the internal transition of the ¹²⁹In^m3.

To confirm this assignment, a spectrum of total counts as a function of time, gated on the 281-keV transition was produced in the same manner as described in Sections III.2.1, III.3.1 and III.4.1. The fit, shown in Figure 10, returned a half-life value of 0.085(15) s, in good agreement with the 0.110(15) s half-life of the 1911-keV ¹²⁹In^m3 state [31] and much shorter than the half-lives of the other $\beta$ -decaying states in ¹²⁹In. This confirms that the presence of the excess intensity at 280 keV was due to the internal transition from ¹²⁹In^m3 to ¹²⁹In^m2.

If this 1911-keV ¹²⁹In^m3 isomer were to populate states in ¹²⁹Sn through $\beta$ -decay, these would have to be very high spin states. One such candidate is the 2552-keV state, with a proposed spin of (27/2^-). Lozeva et al. [21] observed a 146-keV transition from this state to the (23/2^-) 2406-keV state, having populated states in ¹²⁹Sn through ²³⁸U fission and ¹³⁶Xe fragmentation experiments. The present work observed the 146-keV transition in coincidence with the 604-keV transition from the 2406-keV state to the (23/2⁺) 1803-keV state, also observed by Lozeva et al. and shown in Figure 12. Figure 11 shows the coincidence spectrum, produced by gating on the 604-keV transition. This gate clearly shows the presence of the coincidence with the 146-keV $\gamma$ -ray.

An intensity balance calculation of the 2552-keV state implies $\beta$ -feeding, since there is no known higher-lying state in ¹²⁹In that could potentially populate this state. This feeding would amount to the portion represented by the intensity of the 146-keV transition, with respect to the sum of the intensities of the 146-keV and the 281-keV transitions, corrected for internal conversion.

Comparing the $\beta$ -feeding of the 2552-keV state and the 281-keV internal transition yielded a $\beta$ -branching ratio of 2.0(5) $\%$ . The logft value for the $\beta$ -decay of the (29/2⁺) 1911-keV isomer in ¹²⁹In to the (27/2^-) 2552-keV state in ¹²⁹Sn is then 5.68(12), consistent with a first-forbidden transition from the (29/2⁺) ¹²⁹In^m3 state to the (27/2^-) state in ¹²⁹Sn. This logft value is calculated with a half-life of 0.10(1) s, the weighted average of the present result with the literature value. The logft value in this transition is comparable to the 5.8 observed by Gausemel et al. between the (23/2 ${-}$ ) 1630-keV isomer in ¹²⁹In to the (23/2⁺) 1803-keV state ¹²⁹Sn, which is expected given the nearly pure $\pi(g_{9/2}^{-1})\rightarrow\nu(h_{11/2}^{-1})$ $\beta$ transition [17]. This is the first time the 1911-keV isomer in ¹²⁹In has been observed to $\beta$ -decay to excited states of ¹²⁹Sn. Figure 12 shows the partial level schemes of the states in both ¹²⁹In and ¹²⁹Sn involved in this decay.

IV Conclusion

The present work reports new information observed through the $\beta$ -decay of ¹²⁹In to ¹²⁹Sn. The half-lives of the ground state and isomeric states in ¹²⁹In have been confirmed, with the uncertainty in the half-life value of the ¹²⁹In^m2 isomer improved. The level scheme of ¹²⁹Sn has been greatly expanded, with nine new excited states and thirty-one new $\gamma$ -ray transitions. Furthermore, this work observed, for the first time, the $\beta$ -decay of the (29/2⁺) 1911-keV ¹²⁹In^m3 state. More work is needed, in particular in the determination of the spins and parities of the states above the ground state, the 35-keV isomer and the 315-keV first excited state of ¹²⁹Sn. This work provides more rigid constraints on the spins of a number of the excited states, but further studies are needed in order to properly assign these values. This new information on these two nuclei, lying close to doubly magic ${}^{132}_{\texttt{ }50}$ Sn₈₂, provides important constraints and will guide future theoretical models in this region.

Acknowledgements

The authors would like to thank the GRSI collaboration at TRIUMF for their aid during the course of this work. This work was supported, in part, by the Natural Sciences and Engineering Research Council of Canada (NSERC). C.E.S. acknowledges support from the Canada Research Chairs program. Phase I of the GRIFFIN spectrometer was funded by the Canadian Foundation of Innovation (CFI), TRIUMF and the University of Guelph. TRIUMF receives funding from the Canadian Federal Government via a contribution agreement with NRC.

References

Cottle [2010] P. Cottle, Nature 465, 430 (2010).
Bazin [2012] D. Bazin, Nature 486, 330 (2012).
Andreozzi et al. [1997] F. Andreozzi et al., Phys. Rev. C 56, R16(R) (1997).
Otsuka et al. [2001] T. Otsuka et al., Phys. Rev. Lett. 87, 082502 (2001).
Otsuka et al. [2005] T. Otsuka et al., Phys. Rev. Lett. 95, 232502 (2005).
Beun et al. [2009] J. Beun et al., J. Phys. G 36, 025201 (2009).
Surman et al. [2009] R. Surman, J. Beun, G. C. McLaughlin, and W. R. Hix, Phys. Rev. C 79, 045809 (2009).
Burbidge et al. [1957] E. M. Burbidge, G. R. Burbidge, W. A. Fowler, and F. Hoyle, Rev. Mod. Phys. 29, 547 (1957).
Cameron [1957] A. G. W. Cameron, Publ. Astron. Soc. Pac. 69, 201 (1957).
Cameron et al. [1983] A. G. W. Cameron, J. J. Cowan, and J. W. Truran, Astrphys. Space Sci. 91, 235 (1983).
Mumpower et al. [2016] M. R. Mumpower et al., Prog. Part. Nucl. Phys. 86, 86 (2016).
Pinston et al. [2000] J. Pinston et al., Phys. Rev. C 61, 024312 (2000).
Aleklett et al. [1978] K. Aleklett, E. Lund, and G. Rudstam, Phys. Rev. C 18, 462 (1978).
De Geer and Holm [1980] L.-E. De Geer and G. B. Holm, Phys. Rev. C 22, 2163 (1980).
Spanier et al. [1987] L. Spanier, K. Aleklett, B. Ekström, and B. Fogelberg, Nuc. Phys. A 474, 359 (1987).
Huck et al. [1982] H. Huck, M. L. Pérez, and J. J. Rossi, Phys. Rev. C 26, 621 (1982).
Gausemel et al. [2004] H. Gausemel et al., Phys. Rev. C 69, 054307 (2004).
Warner and Reeder [1986] R. Warner and P. Reeder, Radiat. Eff. 94, 27 (1986).
Rudstam et al. [1993] G. Rudstam, K. Aleklett, and L. Sihver, Atomic Data and Nuclear Data Tables 53, 1 (1993).
Genevey et al. [2002] J. Genevey et al., Phys. Rev. C 65, 034322 (2002).
Lozeva et al. [2008] R. L. Lozeva et al., Phys. Rev. C 77, 064313 (2008).
Dilling et al. [2014] J. Dilling, R. Krücken, and G. Ball, Hyperfine Interact. 225, 1 (2014).
Van Duppen [2006] P. Van Duppen, in The Euroschool Lectures on Physics with Exotic Beams Vol II (Springer, 2006).
Bylinskii and Craddock [2013] I. Bylinskii and M. K. Craddock, in ISAC and ARIEL: The TRIUMF Radioactive Beam Facilities and the Scientific Program, edited by J. Dilling, R. Krücken, and L. Merminga (Springer, 2013).
Raeder et al. [2014] S. Raeder et al., Rev. Sci. Instrum. 85, 033309 (2014).
Bricault et al. [2013] P. Bricault et al., in ISAC and ARIEL: The TRIUMF Radioactive Beam Facilities and the Scientific Program, edited by J. Dilling, R. Krücken, and L. Merminga (Springer, 2013).
Svensson and Garnsworthy [2014] C. E. Svensson and A. B. Garnsworthy, Hyperfine Interact 225, 127 (2014).
Garnsworthy et al. [2017] A. B. Garnsworthy et al., Nucl. Instrum. Meth. Phys. Res. A 853, 85 (2017).
Garnsworthy et al. [2019] A. B. Garnsworthy et al., Nucl. Instrum. Meth. Phys. Res. A 918 (2019).
Rizwan et al. [2016] U. Rizwan et al., Nucl. Instrum. Meth. Phys. Res. A 820, 126 (2016).
Timar et al. [2014] J. Timar, Z. Elekes, and B. Singh, Nuc. Data Sheets 121, 143 (2014).
Kibédi et al. [2008] T. Kibédi et al., Nucl. Instrum. Meth. Phys. A 589, 202 (2008).

Spectroscopic studies of neutron-rich 129In and its β\beta-decay daughter, 129Sn, using the GRIFFIN spectrometer

Abstract

pacs:

I Introduction

II Experiment

III Results

III.1 Transitions and Levels in 129Sn

III.2 Decay of the 9/2+ In129{}^{129}\textrm{In} ground state

III.2.1 Half-life of 129Ings

III.2.2 β\beta-feeding and logft values

III.3 Decay of (1/2-) Inm​1129{}^{129}\textrm{In}^{m1}

III.3.1 Half-life of 129Inm1

III.3.2 β\beta-feeding and logft values

III.4 Decay of (23/2-) Inm​2129{}^{129}\textrm{In}^{m2}

III.4.1 Half-life of 129Inm2

III.4.2 β\beta-feeding and logft values

III.5 Decay of (29/2+) Inm​3129{}^{129}\textrm{In}^{m3}