New α-decaying neutron-deficient isotope 196Rn

Pu, Yunfei; Morita, Kosuke; Hies, M.; Lee, K. O.; Yoshida, Akihiro; Nomura, T.; Tagaya, Yu; Motobayashi, T.; Kurokawa, M.; Minemura, H.; Uchibori, T.; Ariga, Tatsuya; Sueki, Keisuke; Shin, Sujin

doi:10.1007/s002180050203

Cited by 15 publications

(6 citation statements)

References 9 publications

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“…Due to the long half-life of 206 Po (T 1/2 = 8.8 d) it was still decaying in the Si detector at the time of the measurement, having been produced during an earlier experiment. An energy of E α = 7048 ± 5 keV has been determined for the decay of 196 At from (60 ± 1) × 10 3 α-decays, and is consistent with the values of 7055 ± 7 keV, 7044 ± 7 keV and 7065 ± 30 keV given in [9][10][11] respectively. A weighted average of the three previously measured results, together with the measurement of this work, gives a value of E α = 7049 ± 4 keV.…”

Section: Resultssupporting

confidence: 82%

Isomeric state in the doubly odd¹⁹⁶At nucleus

Smith

Chapman

Cocks

et al. 2000

J. Phys. G: Nucl. Part. Phys.

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An excited isomeric state has been identified in the 196At nucleus using the recoil decay tagging technique. This is the first identification of an excited state in this neutron-deficient odd-odd nucleus. Several tentative prompt γ-rays have also been correlated with 196At α-decay, although it has not been possible to assign them to specific energy levels in 196At. The mean lifetime of the isomeric state has been measured as τ = 11±2 µs. The new level is compared with similar low-lying states in neighbouring nuclei and is de-excited by an E2 γ-ray transition, the large hindrance of which is not expected.

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Section: Resultssupporting

confidence: 82%

Isomeric state in the doubly odd¹⁹⁶At nucleus

Smith

Chapman

Cocks

et al. 2000

J. Phys. G: Nucl. Part. Phys.

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“…Only one α-decay event was observed for 196 Rn with 5 ms between the implant and the α particle. The same group reported the half-life of 196 Rn as 3 +7−2 ms which agrees with the presently accepted value of 4.4 +1.3 −0.9 ms a year later[68]. The measured half-life of 51 +35 −15 ms for 197 Rn agrees with the present value of 65 +25 −14 ms. Three months later Enquist et al[69] independently reported the observation of the isomeric state which agreed with the value of Morita et al…”

supporting

confidence: 87%

Discovery of the astatine, radon, francium, and radium isotopes

Fry

Thoennessen

2013

Atomic Data and Nuclear Data Tables

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Currently, thirty-nine astatine, thirty-nine radon, thirty-five francium, and thirty-four radium isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented. Contents IntroductionThe discovery of astatine, radon, francium, and radium isotopes is discussed as part of the series summarizing the discovery of isotopes, beginning with the cerium isotopes in 2009 [1]. Guidelines for assigning credit for discovery are (1) clear identification, either through decay-curves and relationships to other known isotopes, particle or γ-ray spectra, or unique mass and Z-identification, and (2) publication of the discovery in a refereed journal. The authors and year of the first publication, the laboratory where the isotopes were produced as well as the production and identification methods are discussed. When appropriate, references to conference proceedings, internal reports, and theses are included. When a discovery includes a half-life measurement the measured value is compared to the currently adopted value taken from the NUBASE evaluation [2] which is based on the ENSDF database [3]. In cases where the reported half-life differed significantly from the adopted half-life (up to approximately a factor of two), we searched the subsequent literature for indications that the measurement was erroneous. If that was not the case we credited the authors with the discovery in spite of the inaccurate half-life. All reported half-lives inconsistent with the presently adopted half-life for the ground state were compared to isomer half-lives and accepted as discoveries if appropriate following the criterium described above.The first criterium is not clear cut and in many instances debatable. Within the scope of the present project it is not possible to scrutinize each paper for the accuracy of the experimental data as is done for the discovery of elements [4]. In some cases an initial tentative assignment is not specifically confirmed in later papers and the first assignment is tacitly accepted by the community. The readers are encouraged to contact the authors if they disagree with an assignment because they are aware of an earlier paper or if they found evidence that the data of the chosen paper were incorrect.The discovery of several isotopes has only been reported in conference proceedings which are not accepted according to the second criterium. One example from fragmentation experiments why publications in conference proceedings should not be considered is 118 Tc and 120 Ru which had been reported as being discovered in a conference proceeding [5] but not in the subsequent refereed publication [6]. 2 The initial literature search was performed using the databases ENSDF [3] and NSR [7] of the National Nuclear Data Center at Brookhaven National Laboratory. These databases are complete and reliable back to the early 1960's. For earlier references, several editions of the Table of Iso...

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“…Six decay chains were assigned to the 13/2 + state and one decay chain was assigned to the 3/2 − state. A subsequent measurement with improved precision was performed at RITU using the reactions 65 Cu + 141 Pr at E beam = (283-293) MeV and 36 Ar + 170 Yb at E beam = (180-185) MeV [7]. In this later study, two α-decaying states were also observed.…”

Section: Resultsmentioning

confidence: 99%

“…Both events were registered in experiments at the gas-filled recoil separator RITU at the Department of Physics of the University of Jyväskylä (JYFL) in Finland. One event was produced in the reaction 36 Ar + 170 Yb at a beam energy of 201 MeV yielding E α = 7860(60) keV, T 1/2 = 0.7 +3.3 −0.3 ms [18]. The α particle tentatively assigned to the decay of 202 Ra was followed by two escaped α particles.…”

Section: Resultsmentioning

confidence: 99%