Nuclear Data Sheets for A = 266–294

doi:10.1016/j.nds.2005.10.005

Nuclear Data Sheets

Volume 106, Issue 2, October 2005, Pages 251-366

https://doi.org/10.1016/j.nds.2005.10.005 Get rights and content

Abstract

The 2000 Nuclear Data Sheets for A = 267–293 (2000Fi12) and part (A = 266) of the 2001 Nuclear Data Sheets for 250,254,258,262,266 (2001Ak11) have been revised using experimental decay and reaction data received by August 12, 2005.

References (158)

V.E. Viola et al.
J. Inorg. Nucl. Chem.
(1966)
J.J. Wesolowski et al.
Phys. Lett. B
(1969)
D.C. Aumann et al.
Nucl. Instrum. Methods
(1974)
G. Mullen et al.
Nucl. Instrum. Methods
(1975)
H.W. Gaggeler et al.
Nucl. Instrum. Methods Phys. Res. A
(1991)
K.E. Gregorich
Nucl. Instrum. Methods Phys. Res. A
(1991)
R.C. Barber et al.
Prog. Part. Nucl. Phys.
(1992)
A.V. Yeremin et al.
Nucl. Instrum. Methods Phys. Res. A
(1994)
P. Moller et al.
At. Data Nucl. Data Tables
(1995)
K.W. Scheller et al.
Nucl. Phys. A
(1995)

W.D. Myers et al.

Nucl. Phys. A

(1996)

P. Moller et al.

At. Data Nucl. Data Tables

(1997)

A.V. Yeremin et al.

Nucl. Instrum. Methods Phys. Res. B

(1997)

A. Artna-Cohen

Nucl. Data Sheets

(1999)

R.B. Firestone et al.

Nucl. Data Sheets

(2000)

Y.A. Akovali

Nucl. Data Sheets

(2001)

I.M. Band et al.

At. Data Nucl. Data Tables

(2002)

Ch.E. Dullmann et al.

Nucl. Instrum. Methods Phys. Res. A

(2002)

V.M. Lobashev

Prog. Part. Nucl. Phys.

(2002)

G. Igo

Phys. Rev.

(1959)

D.N. Schramm et al.

Nature (London)

(1971)

F.H. Geisler et al.

Nature (London)

(1973)

K. Behringer et al.

Phys. Rev. C

(1974)

W. Stephens et al.

Phys. Rev. C

(1980)

G. Munzenberg et al.

Z. Phys. A

(1982)

S. Mordechai et al.

Phys. Rev. C

(1984)

G. Munzenberg et al.

Z. Phys. A

(1984)

Yu.Ts. Oganessian et al.

Radiochim. Acta

(1984)

K.-H. Schmidt et al.

Z. Phys. A

(1984)

I. Zvara et al.

Radiokhimiya

(1984)

Sov. Radiochem.

(1984)

D.C. Hoffman et al.

Phys. Rev. C

(1985)

G. Munzenberg et al.

Z. Phys. A

(1987)

M. Schadel, W. Bruchle, E. Jager, K. Summerer, E.K. Hulet, J.F. Wild, R.W. Lougheed, R.J. Dougan, K.J. Moody –...

G. Munzenberg et al.

Z. Phys. A

(1988)

G. Munzenberg

Nucl. Phys. A

(1989)

Yu.Ts. Oganessian et al.

D.C. Hoffman et al.

Phys. Rev. C

(1990)

Yu.A. Lazarev et al.

Phys. Rev. Lett.

(1994)

A. Ghiorso et al.

Nucl. Phys. A

(1995)

A. Ghiorso et al.

Phys. Rev. C

(1995)

S. Hofmann et al.

Z. Phys. A

(1995)

S. Hofmann et al.

Z. Phys. A

(1995)

D.C. Hoffman et al.

Radiochim. Acta

(1995)

Yu.A. Lazarev et al.

Phys. Rev. Lett.

(1995)

M. Schadel et al.

Radiochim. Acta

(1995)

R. Smolanczuk et al.

Phys. Rev. C

(1995)

R. Smolanczuk et al.

H. Heiselberg et al.

Phys. Rev. C

(1996)

S. Hofmann et al.

Z. Phys. A

(1996)

Cited by (49)

Nuclear Data Sheets for A=268,272,276,280,284,288,292
2019, Nuclear Data Sheets
Spectroscopic information such as production, identification, half-lives, decay modes and possible excited states for experimentally known nuclides of mass numbers 268, 272, 276, 280, 284, 288, and 292 are presented together with the recommended values, superseding information and data in the previous ENSDF and NDS evaluation by 2005Gu33. No nuclides have yet been identified for A=296 and 300. In the last 14 years, large amounts of new and definitive data on the superheavy nuclides (SHN) have become available, thus changing almost entirely the landscape of nuclear data in this mass region, as also indicated by a number of recent review articles: 2017Og01, 2016Ho09, 2016Ho06 (for fission barriers), 2016Fo10, 2015Og05, 2015Og07, and 2013Th02. See 2003Ka71 and 2001Ka70 for IUPAC technical discussions about the discovery of Z=111 (Rg) and 2009Ba62 for discovery of Z=112(Cn), 2011Ba54 for discovery of Z=114 (Fl) and Z=116 (Lv) and 2016Ka49 for discovery of Z=113 (Nh) and Z=115 (Mc). A special issue of Nuclear Physics A444 (2015) is devoted to research on superheavy elements (SHE) with 27 articles. In particular, see article by 2015Ko20 on mass spectrometric searches for superheavy elements in terrestrial matter. See also Proceedings of Nobel Symposium NS160 ‘Chemistry and Physics of Heavy and Superheavy Elements’ published in Eur. Phys. Jour. Web of Conferences 131 (2016), in particular 2016UtZZ, 2016DmZZ and 2016HoZY.
A=268: ²⁶⁸Db, ²⁶⁸Hs and ²⁶⁸Mt are the only experimentally identified nuclides with A=268.
A=272: ²⁷²Bh and ²⁷²Rg are the only experimentally identified nuclides with A=272. A tentative level scheme for ²⁷²Bh has been proposed from the decay of ²⁷⁶Mt. Search for ²⁷²Ds in ²³⁵U(⁴⁰Ar,3n),E=5.1-5.4 MeV/nucleon reaction and subsequent α decays at GSI (1990Sc11) proved negative with $σ < 0.8 nb$ .
A=276: ²⁷⁶Mt is the only experimentally identified nuclide with A=276. A tentative level scheme has been proposed for this nuclide.
A=280: ²⁸⁰Rg is the only experimentally identified nuclide with A=280. A tentative evidence is reported (2017Ka66) for ²⁸⁰Ds, based on one possible α-α-α correlated event at RIKEN.
A=284: ²⁸⁴Cn, ²⁸⁴Nh and ²⁸⁴Fl are the only experimentally identified nuclides with A=284. First measurement of mass/charge (A/q) ratio has been made by 2018Ga34, resulting in the determination of A=284 for ²⁸⁴Nh.
A=288: ²⁸⁸Fl and ²⁸⁸Mc are the only experimentally identified nuclides with A=288. Two independent experiments, first by Dubna-Livermore-ORNL collaboration using DGFRS at FLNR-JINR-Dubna (2004Og07,2004Og12), and the second at GSI using TASCA (2010Du06,2011Ga19) have confirmed the existence of ²⁸⁸Fl and ²⁸⁸Mc; and a third experiment at LBNL-Berkeley using BGS (2015Ga24) further confirmed the existence of ²⁸⁸Mc. Chemistry-related experiments for ²⁸⁸Fl have been reported by 2014Ya33 and 2010Ei01. First measurement of mass/charge (A/q) ratio has been made by 2018Ga34, resulting in the determination of A=288 for ²⁸⁸Mc. Search for ²⁸⁸Ds in natural Pt, Pb and Bi samples (2011De21) using accelerator mass spectroscopy (AMS) proved negative, with extremely low upper limits established.
A=292: ²⁹²Lv is the only experimentally identified nuclide with A=292. Two independent experiments, one by Dubna-Livermore collaboration (2004Og12,2004OgZZ), and the other at GSI-SHIP facility (2012Ho12) confirm the identification of ²⁹²Lv, with the assignment of ten correlated events composed of Evaporation Residues (EVR)-α1-α2-SF correlated decay chains. Search for ²⁹²Rg in natural gold materials (2011De03), and for ²⁹²Ds and ²⁹²Fl in natural Pt, Pb and Bi samples (2011De21) using accelerator mass spectroscopy (AMS) proved negative, with extremely low upper limits established. 2010Ma03 proposed the existence of a very long-lived isomer in ¹²²292 in their search of superheavy elements in natural Th sample using inductively-coupled plasma sector field mass spectroscopy, and interpreted the observed events as due to high-spin isomers of superdeformed or hyperdeformed character. This claim, however, for other nuclides in the superheavy element region has not been verified, for example in the AMS studies of natural samples such as Pt, Os, Au, Pb and Bi by 2011De21 and 2011De03. See also the publications of the Joint Working Party (JWP) of the IUPAC-IUPAP with critical appraisal of studies dealing with search of superheavy elements in natural samples. Specifically, for A=292, 2011De21 and 2011De21, using AMS technique, found no evidence for the existence of ²⁹²Ds, ²⁹²Rg and ²⁹²Fl in natural Pt, Pb, Bi and Au samples. See also replies to above critiques by 2009Ma19, Marinov et al., arXiv:0909.1057 (2009), and 2004MaZS
A=296: Search for ²⁹⁶Rg in natural gold materials (2011De03), and for ²⁹⁶Fl and ²⁹⁶Mc in natural Pt, Pb and Bi samples (2011De21) using accelerator mass spectroscopy (AMS) proved negative, with extremely low upper limits established. See 2016DuZX for future prospects of discovery of elements beyond Z=118. There are no data tables for A=296.
A=300: Search for ³⁰⁰Mc in natural Pt, Pb and Bi samples (2011De21) using accelerator mass spectroscopy (AMS) proved negative, with extremely low upper limits established. There are no data tables for A=300.
Nuclear Data Sheets for A=266,270,274,278,282,286,290,294,298
2019, Nuclear Data Sheets
Spectroscopic information such as production, identification, half-lives, decay modes and possible excited states for experimentally known nuclides of mass numbers 266, 270, 274, 278, 282, 286, 290, 294, and 298 are presented together with the recommended values, superseding information and data in the previous ENSDF and NDS evaluation by 2005Gu33. No nuclides have yet been identified for A=302. In the last 14 years, large amounts of new and definitive data on the superheavy nuclides (SHN) have become available, thus changing almost entirely the landscape of nuclear data in this mass region, as also indicated by a number of recent review articles: 2017Og01, 2016Ho09, 2016Ho06 (for fission barriers), 2015Og05, 2015Og07, 2015Mo25, 2015OgZX, 2013Th02, and 2011Og07. See 2016Ka49 for IUPAC technical discussions for the discovery of Z=117 (Ts), Z=115 (Mc), Z=113 (Nh), 2001Ka70 and 2003Ka71 for Z=110-112, 2011Ba54 for Z≥113, 2009Ba62 for Z=112, and 2016Ka50 for Z=118 (Og). A special issue of Nuclear Physics A444 (2015) is devoted to research on superheavy elements (SHE) with 27 articles. In particular, see article by 2015Ko20 on mass spectrometric searches for superheavy elements in terrestrial matter. See also Proceedings of Nobel Symposium NS160 ‘Chemistry and Physics of Heavy and Superheavy Elements’ published in Eur. Phys. Jour. Web of Conferences 131 (2016), in particular 2016UtZZ, 2016DmZZ and 2016HoZY. See also 2016DuZX for future prospects of discovery of elements beyond Z=118
A=266: ²⁶⁶Db, ²⁶⁶Sg, ²⁶⁶Bh, ²⁶⁶Hs and ²⁶⁶Mt are the experimentally identified nuclides with A=266. Identification of ²⁶⁶Lr from α decay of ²⁷⁰Db has been proposed by 2014Kh04 from experiments at GSI, but complete details and analyses of all the four decay chains reported in this experiment have not yet been published, and discussion in 2015Og05 review article considering their work from Dubna (2013Og04, 2011Og04) and from GSI (2014Kh04) still concluded that ²⁷⁰Db decayed dominantly by SF mode, in contrast with dominant α decay mode proposed by 2014Kh04. Experiments carried out at FLNR-JINR-Dubna in collaboration with LLNL and ORNL, GSI-SHIP facility, RIKEN, and LBNL facilities: ²⁶⁶Db from the α-decay of ²⁸²Nh in two correlated decay chains at Dubna; ²⁶⁶Sg as α-daughter of ²⁷⁰Hs in 12 correlated decay chains at Dubna and GSI; ²⁶⁶Bh in α decay of ²⁷⁸Nh in three correlated decay chains observed at RIKEN, and also directly with one event in ²⁴⁹Bk(²²Ne,5n) at LBNL, and with four events in ²⁴³Am(²⁶Mg,3n) at HIRFL-Lanzhou; ²⁶⁶Hs as α-daughter of ²⁷⁰Ds at GSI in two different experiments, six correlated decays in the first, and 25 decay chains in the second experiment, the analysis of which has not been fully reported as yet; and ²⁶⁶Mt directly in ²⁰⁹Bi(⁵⁸Fe,n) reaction at GSI in two different experiments, observing three events in the first experiment and 12 events in the second, also produced in ²⁰⁸Pb(⁵⁹Co,n) reaction at LBNL, observing five correlated decay chains. See also 2000Ho27 for discussion on ²⁶⁶Sg and ²⁶⁶Mt.
A=270: ²⁷⁰Db, ²⁷⁰Bh, ²⁷⁰Hs, ²⁷⁰Mt and ²⁷⁰Ds are the experimentally identified nuclides with A=270 are presented. Experiments carried out at FLNR-JINR-Dubna in collaboration with LLNL and ORNL, GSI-SHIP facility, and RIKEN: ²⁷⁰Db from the decay of ²⁹⁴Ts in six correlated decay chains at Dubna and GSI; ²⁷⁰Bh as α great-granddaughter of ²⁸²Nh in two correlated decay chains observed at Dubna; ²⁷⁰Hs directly in ²⁴⁸Cm(²⁶Mg,4n) reaction at GSI, and in ²²⁶Ra(⁴⁸Ca,4n) reaction at Dubna; ²⁷⁰Mt as granddaughter of ²⁷⁸Ts in three correlated decay chains at RIKEN; and ²⁷⁰Ds directly in ²⁰⁷Pb(⁶⁴Ni,n) at GSI in 33 correlated decay chains.
A=274: ²⁷⁴Bh, ²⁷⁴Mt and ²⁷⁴Rg are the experimentally identified nuclides with A=274. Search for ²⁷⁴Ds in ²³⁸U(⁴⁰Ar, 4n),E=5.7 MeV/nucleon reaction and subsequent α decays at GSI (1990Sc11) proved negative. Experiments carried out at FLNR-JINR-Dubna in collaboration with LLNL and ORNL, GSI-SHIP facility, and RIKEN: ²⁷⁴Bh from the decay of ²⁹⁴Ts in six correlated decay chains at Dubna and GSI, ²⁷⁴Mt produced as α daughter of ²⁸²Nh in two correlated decay chains observed at Dubna, and ²⁷⁴Rg as α daughter of ²⁷⁸Nh produced in three correlated decay chains at RIKEN.
A=278: ²⁷⁸Mt, ²⁷⁸Rg and ²⁷⁸Nh are the experimentally identified nuclides with A=278. A very tentative evidence is provided for ²⁷⁸Bh and ²⁷⁸Hs from a chain originally observed and assigned to ²⁸⁹Fl by 1999Og10, but later reassigned by 2004Og10 to ²⁹⁰Fl, and further discussed in detail by 2016Ho09, where, based on systematics of α decays and SF half-lives, ²⁹⁰Fl is proposed to decay via ε mode to ²⁹⁰Nh, which then decays by an α chain, ending in ²⁷⁸Bh that decays by SF mode. Experiments carried out at FLNR-JINR-Dubna in collaboration with LLNL and ORNL labs in the USA, GSI-SHIP facility, and RIKEN: ²⁷⁸Mt from the decay of ²⁹⁴Ts in six correlated decay chains at Dubna and GSI, ²⁷⁸Rg produced as α daughter of ²⁸²Nh in two correlated decay chains observed at Dubna, and ²⁷⁸Nh produced directly in three correlated decay chains at RIKEN.
A=282: ²⁸²Rg, ²⁸²Cn and ²⁸²Nh are the experimentally identified nuclides with A=282. A very tentative evidence is provided for ²⁸²Mt and ²⁸²Ds from a chain originally observed and assigned to ²⁸⁹Fl by 1999Og10, but later reassigned by 2004Og10 to ²⁹⁰Fl, and further discussed in detail by 2016Ho09, where, based on systematics of α decays and SF half-lives, ²⁹⁰Fl is proposed to decay via ε mode to ²⁹⁰Nh, which then decays by an α chain, ending in ²⁷⁸Bh that decays by SF mode. Experiments carried out at FLNR-Dubna, in collaboration with LLNL and ORNL labs in the USA, and at GSI-SHIP facility confirm the identification of these isotopes, ²⁸²Rg in α decay chain of ²⁹⁴Ts in six correlated decay chains at Dubna and GSI, ²⁸²Cn produced in four ways at Dubna: independently in one correlated decay chain, as α daughter of ²⁸⁶Lv in 11 correlated decay chains, as α grand-daughter of ²⁹⁰Lv in 12 correlated decay chains, as α great-grand daughter of ²⁹⁴Og in four correlated decay chains, and ²⁸²Nh produced at Dubna directly in two correlated decay chains.
A=286: ²⁸⁶Nh and ²⁸⁶Fl are the only experimentally identified nuclides with A=286. A very tentative evidence is provided for ²⁸⁶Rg and ²⁸⁶Cn from a chain originally observed and assigned to ²⁸⁹Fl by 1999Og10, but later reassigned by 2004Og10 to ²⁹⁰Fl, and further discussed in detail by 2016Ho09, where, based on systematics of α decays and SF half-lives, ²⁹⁰Fl is proposed to decay via ε mode to ²⁹⁰Nh, which then decays by an α chain, ending in ²⁷⁸Bh that decays by SF mode. 2017Ka66 in experiments at RIKEN using GARIS separator interpret one correlated decay chain in three different ways, one involving possible production of ²⁹⁴Lv in ²⁴⁸Cm(⁴⁸Ca,2n),E=261.6 MeV, and α decay to ²⁹⁰Fl which further decays to ²⁸⁶Cn. Experiments carried out at FLNR-Dubna, in collaboration with LLNL and ORNL labs in the USA, and at GSI-SHIP facility confirm the identification of these isotopes, ²⁸⁶Nh as α grand-daughter of ²⁹⁴Ts in six correlated decay chains, and ²⁸⁶Fl produced in three ways: independently in 11 correlated decay chains, as α daughter of ²⁹⁰Lv in 12 correlated decay chains, and as α grand-daughter of ²⁹⁴Og in four correlated decay chains.
A=290: ²⁹⁰Mc and ²⁹⁰Lv are the only experimentally identified nuclides with A=290. A tentative evidence is provided for ²⁹⁰Nh and ²⁹⁰Fl from a chain originally observed and assigned to ²⁸⁹Fl by 1999Og10, but later reassigned by 2004Og10 to ²⁹⁰Fl, and further discussed in detail by 2016Ho09, where, based on systematics of α decays and SF half-lives, ²⁹⁰Fl is proposed to decay via ε mode to ²⁹⁰Nh, which then decays by an α chain, ending in ²⁷⁸Bh that decays by SF mode. 2017Ka66 in experiments at RIKEN using GARIS separator interpret one correlated decay chain in three different ways, one involving possible production of ²⁹⁴Lv in ²⁴⁸Cm(⁴⁸Ca,2n),E=261.6 MeV, and α decay to ²⁹⁰Fl. Experiments carried out at FLNR-Dubna, in collaboration with LLNL and ORNL labs in the USA, and at GSI-SHIP facility confirm the identification of these isotopes, ²⁹⁰Mc as α daughter of ²⁹⁴Ts in six correlated decay chains, and ²⁹⁰Lv produced in two ways, independently in 14 correlated decay chains, and as α daughter of ²⁹⁴Og in four correlated decay chains.
A=294: ²⁹⁴Ts and ²⁹⁴Og are the only experimentally identified nuclides with A=294. Experiments carried out at FLNR-Dubna, in collaboration with LLNL and ORNL labs in the USA, and at GSI-SHIP facility confirm the identification of these isotopes, with a total of six EVR-α-SF correlated decay chains observed for ²⁹⁴Ts and four for ²⁹⁴Og. Tentative identification of ²⁹⁴Lv is provided by 2017Ka66 from the observation one correlated event using GARIS-RIKEN facility, where this event is interpreted in three possible ways, two interpretations lead to production of ²⁹³Lv and successive odd-A nuclides of ²⁸⁹Fl, ²⁸⁵Cn and ²⁸¹Ds, whereas the third prediction starts with the production of ²⁹⁴Lv and successive ²⁹⁰Fl and ²⁸⁶Cn nuclides. Search for ²⁹⁴Rg in natural gold materials (2011De03), and for ²⁹⁴Ds, ²⁹⁴Fl and ²⁹⁴Mc in natural Pt, Pb and Bi samples (2011De21) using accelerator mass spectroscopy (AMS) proved negative, with extremely low upper limits established. Also 1980St05 did not see any evidence for ²⁹⁴Ds in natural Pt sample using AMS.
A=298: Search for ²⁹⁸120 through fusion-evaporation reaction at Dubna, and for ²⁹⁸Fl and ²⁹⁸Mc in natural Pt, Pb and Bi samples using accelerator mass spectroscopy (AMS) proved negative. Tentative assignment of three α-α-α decay chains by 2016Ho09 to ²⁹⁹120 in ²⁴⁸Cm(⁵⁴Cr,3n)²⁹⁹120 at GSI was refuted by 2017He11, assigning these correlations to random events, instead.
A=302: Fluorescent x rays from Z=120 element were observed by 2012Fr03 from compound nucleus ³⁰²120 produced in ²³⁸U(⁶⁴Ni,X),E=6.6 MeV/nucleon at GANIL, and x-ray yields were measured, together with minimum average time deduced from x-ray multiplicity. The compound nucleus could decay by 3n- or 4n-channels to produce ²⁹⁹120 or ²⁹⁸120. 2012He05 and 2016Ho09 also produced ³⁰²120 compound nucleus in ²⁴⁸Cm(⁵⁴Cr, xn)³⁰²120^*,E=6.035 MeV/nucleon; and ²³⁸U(⁶⁴Ni,xn)³⁰²120^*,E=5.53 MeV/nucleon reactions using UNILAC at GSI. Three α-α-α correlated decays from ²⁴⁸Cm(⁵⁴Cr,xn)³⁰²120^* reaction were tentatively assigned by 2016Ho09 to ²⁹⁹120 decay, however, a detailed analysis by 2017He11 refuted this claim, ascribing these events to random sequences. There are no data tables for A=302.
Branching ratios of α-decay to ground and excited states of Fm, Cf, Cm and Pu
2018, Nuclear Physics A
We use the well-known Wentzel–Kramers–Brillouin (WKB) barrier penetration probability to calculate α-decay branching ratios for ground and excited states of heavy even–even nuclei of Fermium ( $^{248 – 254}$ Fm), Californium ( $^{244 – 252}$ Cf), Curium ( $^{238 – 248}$ Cm) and Plutonium ( $^{234 – 244}$ Pu) with $94 \leq Z_{p} \leq$ 100. We obtained the branching ratios for the excited states of daughter nucleus by the α-decay energy (Q_α), the angular momentum of α-particle ( $ℓ_{α}$ ), and the excitation probability of the daughter nucleus with the excitation energy of state ℓ in the daughter nucleus (i.e. E $_{ℓ}^{⁎}$ ). α-Decay half-lives have been evaluated by using the proximity potential model for the heavy even–even nuclei. We have reported the half-lives and compared the results with the experimental data. The theoretical branching ratios of α-transitions in our calculation are found to agree with the available experimental data well for 0 ${}^{+}\to$ 0⁺, 0 ${}^{+}\to$ 2⁺, 0 ${}^{+}\to$ 4⁺, 0 ${}^{+}\to$ 6⁺ and 0⁺ → 8⁺ α-transitions.
Systematic study of α-decay half-lives using Royer and related formula
2018, Nuclear Physics A
The alpha decay half-lives of 356 isotopes were studied using the Royer and related Formula and are compared with experimental data. The study shows that the predicted half-lives match well with experimental data over a wide range for each $(Z, N)$ parity of the parent nuclei. We have calculated the standard deviation of $\log_{10} T_{α} (s)$ , for each formula and our study indicate that, for alpha decay studies, generally, analytical ℓ-dependent formula proposed by Royer, with $σ^{RB} = 0.4373$ , is the best model followed by the formula proposed by Denisov and Khudenko (DK), $σ^{DK} = 0.4743$ for all 356 nuclei. We hope the present study is a clear indicator of the predictive power of Royer and related formula.
Predictions on the modes of decay of even Z superheavy isotopes within the range 104≤Z≤136
2018, Atomic Data and Nuclear Data Tables
Citation Excerpt :
Various phenomenological and microscopic models such as fission model [27], cluster model [28], generalized liquid drop model (GLDM) [29], unified model for alpha-decay and alpha-capture (UMADAC) [30] have been employed to study the process of alpha decay [30–36]. Simple empirical relations and various analytical formulae [37–41] are also available for determining the alpha decay half-lives. Earlier studies on spontaneous radioactive processes treat alpha decay and spontaneous fission (SF) as two completely different mechanisms while considering the nuclear structure properties.
The decay modes and half lives of all the even $Z$ isotopes of superheavy elements within the range $104 \leq Z \leq 136$ have been predicted by comparing the alpha decay half-lives with the spontaneous fission half-lives. The Coulomb and proximity potential model for deformed nuclei (CPPMDN) and the shell-effect-dependent formula of Santhosh et al. are used to calculate the alpha half-lives and spontaneous fission half-lives respectively. For theoretical comparison the alpha decay half-lives are also calculated using Coulomb and proximity potential model (CPPM), the Viola–Seaborg–Sobiczewski semi-empirical (VSS) relation, the universal (UNIV) curve of Poenaru et al., the analytical formula of Royer and the universal decay law (UDL) of Qi et al. Another tool used for the evaluation of spontaneous fission half-lives is the semi-empirical formula of Xu et al. The nuclei with alpha decay half-lives less than spontaneous fission half-lives will survive fission and hence decay through alpha emission. The predicted half lives and decay modes are compared with the available experimental results. The one-proton and two-proton separation energies of all the isotopes are calculated to find nuclei which lie beyond the proton drip line. Among 1119 even $Z$ nuclei within the range $104 \leq Z \leq 136$ , 164 nuclei show sequential alpha emission followed by subsequent spontaneous fission. Since the isotopes decay through alpha decay chain and the half-lives are in measurable range, these isotopes are predicted to be synthesized and detected in laboratory via alpha decay. 2 nuclei will decay by alpha decay followed by proton emission, 54 nuclei show full alpha chains, 642 nuclei will decay through spontaneous fission, 166 nuclei exhibit proton decay and 91 isotopes are found to be stable against alpha decay. All the isotopes are tabulated according to their decay modes. The study is intended to enhance further experimental investigations in superheavy region.
Quantum design using a multiple internal reflections method in a study of fusion processes in the capture of alpha-particles by nuclei
2015, Nuclear Physics A
Citation Excerpt :
Information about fusion in α-capture forms our understanding of interactions between the α-particles and nuclei at distances, where an important role is attributed to the formation of the nucleus from two colliding nuclear objects inside the spatial nuclear region. α–nucleus interactions have been studied most intensively in the context of the α-decay of nuclei (see experimental information [4–16], various microscopic models [17–30], macroscopic cluster models [31–44], fission models [3,46]), and the scattering of the α-particles off nuclei [47–51]. The physics of the fusion processes during α-capture has been investigated less deeply [36–39].
A high precision method to determine fusion in the capture of α-particles by nuclei is presented. For α-capture by ⁴⁰Ca and ⁴⁴Ca, such an approach gives (1) the parameters of the α–nucleus potential and (2) fusion probabilities. This method found new parametrization and fusion probabilities and decreased the error by 41.72 times for $α + {}^{40}{Ca}$ and 34.06 times for $α + {}^{44}{Ca}$ in a description of experimental data in comparison with existing results. We show that the sharp angular momentum cutoff proposed by Glas and Mosel is a rough approximation, Wong's formula and the Hill–Wheeler approach determine the penetrability of the barrier without a correct consideration of the barrier shape, and the WKB approach gives reduced fusion probabilities. Based on our fusion probability formula, we explain the difference between experimental cross-sections for $α + {}^{40}{Ca}$ and $α + {}^{44}{Ca}$ , which is connected with the theory of coexistence of the spherical and deformed shapes in the ground state for nuclei near the neutron magic shell $N = 20$ . To provide deeper insight into the physics of nuclei with the new magic number $N = 26$ , the cross-section for $α + {}^{46}{Ca}$ is predicted for future experimental tests. The role of nuclear deformations in calculations of the fusion probabilities is analyzed.

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^☆: This work was performed under the auspices of the U.S. Department of Energy, Contract No. DE-AC02-98CH10886, and Brookhaven National Laboratory Contract No. 92389.

^a: Permanent address: Manipal Academy of Higher Education, Manipal, KA 576 104, INDIA

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Nuclear Data Sheets for A = 266–294☆

Abstract

J. Inorg. Nucl. Chem.

Phys. Lett. B

Nucl. Instrum. Methods

Nucl. Instrum. Methods

Nucl. Instrum. Methods Phys. Res. A

Nucl. Instrum. Methods Phys. Res. A

Prog. Part. Nucl. Phys.

Nucl. Instrum. Methods Phys. Res. A

At. Data Nucl. Data Tables

Nucl. Phys. A

Nucl. Phys. A

At. Data Nucl. Data Tables

Nucl. Instrum. Methods Phys. Res. B

Nucl. Data Sheets

Nucl. Data Sheets

Nucl. Data Sheets

At. Data Nucl. Data Tables

Nucl. Instrum. Methods Phys. Res. A

Prog. Part. Nucl. Phys.

Phys. Rev.

Nature (London)

Nature (London)

Phys. Rev. C

Phys. Rev. C

Z. Phys. A

Phys. Rev. C

Z. Phys. A

Radiochim. Acta

Z. Phys. A

Radiokhimiya

Sov. Radiochem.

Phys. Rev. C

Z. Phys. A

Z. Phys. A

Nucl. Phys. A

Phys. Rev. C

Phys. Rev. Lett.

Nucl. Phys. A

Phys. Rev. C

Z. Phys. A

Z. Phys. A

Radiochim. Acta

Phys. Rev. Lett.

Radiochim. Acta

Phys. Rev. C

Phys. Rev. C

Z. Phys. A