K. P. Rykaczewski
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View article: Direct observation of the superallowed α decay of 104Te
Direct observation of the superallowed α decay of 104Te Open
Alpha particle radioactivity is one of the most striking evidence for the existence of cluster structures in atomic nuclei. During the decay process, a preexisting α particle tunnels through the potential barrier formed by the residual nuc…
View article: Modeling of Light Production in Inorganic Scintillators
Modeling of Light Production in Inorganic Scintillators Open
In recent experiments, inorganic scintillators have been used to study the decays of exotic nuclei, providing an alternative to silicon detectors and enabling measurements that were previously impossible. However, proper use of these mater…
View article: Universal Effective Charges in the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi>s</mml:mi><mml:mi>d</mml:mi></mml:mrow></mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi>f</mml:mi><mml:mi>p</mml:mi></mml:mrow></mml:math> Shells
Universal Effective Charges in the and Shells Open
The 247-keV state in ^{54}Sc, populated in the β decay of ^{54}Ca, is reported here as a nanosecond isomer with a half-life of 26.0(22) ns. The state is interpreted as the 1^{+} member of the πf_{7/2}⊗νf_{5/2} spin-coupled multiplet, which…
View article: Impact of Newly Measured <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>β</mml:mi></mml:math>-Delayed Neutron Emitters around <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mmultiscripts><mml:mrow><mml:mi>Ni</mml:mi></mml:mrow><mml:mprescripts/><mml:none/><mml:mrow><mml:mn>78</mml:mn></mml:mrow></mml:mmultiscripts></mml:mrow></mml:math> on Light Element Nucleosynthesis in the Neutrino Wind Following a Neutron Star Merger
Impact of Newly Measured -Delayed Neutron Emitters around on Light Element Nucleosynthesis in the Neutrino Wind Following a Neutron Star Merger Open
Neutron emission probabilities and half-lives of 37 β-delayed neutron emitters from Ni
View article: Competition between mass-symmetric and asymmetric fission modes in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi>Md</mml:mi><mml:mprescripts/><mml:none/><mml:mn>258</mml:mn></mml:mmultiscripts></mml:math> produced in the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mmultiscripts><mml:mi>He</mml:mi><mml:mprescripts/><mml:none/><mml:mn>4</mml:mn></mml:mmultiscripts><mml:mo>+</mml:mo><mml:mmultiscripts><mml:mi>Es</mml:mi><mml:mprescripts/><mml:none/><mml:mn>254</mml:mn></mml:mmultiscripts></mml:mrow></mml:math> reaction
Competition between mass-symmetric and asymmetric fission modes in produced in the reaction Open
View article: Discovery of 98Sn Produced by the Projectile Fragmentation of a 345-MeV/Nucleon 124Xe Beam
Discovery of 98Sn Produced by the Projectile Fragmentation of a 345-MeV/Nucleon 124Xe Beam Open
We present the discovery of a new isotope of $^{98}$Sn beyond the double-magic N = Z = 50 nucleus $^{100}$Sn. $^{98}$Sn was identified among the projectile-fragmentation products of a $^{124}$Xe beam at 345 MeV/nucleon at the RI Beam Facto…
View article: YSO implantation detector for beta-delayed neutron spectroscopy
YSO implantation detector for beta-delayed neutron spectroscopy Open
View article: First Exploration of Monopole-Driven Shell Evolution above the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi>N</mml:mi><mml:mo>=</mml:mo><mml:mn>126</mml:mn></mml:mrow></mml:math> Shell Closure: New Millisecond Isomers in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mmultiscripts><mml:mrow><mml:mi>Tl</mml:mi></mml:mrow><mml:mprescripts/><mml:none/><mml:mrow><mml:mn>213</mml:mn></mml:mrow></mml:mmultiscripts></mml:mrow></mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mmultiscripts><mml:mrow><mml:mi>Tl</mml:mi></mml:mrow><mml:mprescripts/><mml:none/><mml:mrow><mml:mn>215</mml:mn></mml:mrow></mml:mmultiscripts></mml:mrow></mml:math>
First Exploration of Monopole-Driven Shell Evolution above the Shell Closure: New Millisecond Isomers in and Open
Isomer spectroscopy of heavy neutron-rich nuclei beyond the N=126 closed shell has been performed for the first time at the Radioactive Isotope Beam Factory of the RIKEN Nishina Center. New millisecond isomers have been identified at low e…
View article: Proton Shell Gaps in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi>N</mml:mi><mml:mo>=</mml:mo><mml:mn>28</mml:mn></mml:mrow></mml:math> Nuclei from the First Complete Spectroscopy Study with FRIB Decay Station Initiator
Proton Shell Gaps in Nuclei from the First Complete Spectroscopy Study with FRIB Decay Station Initiator Open
The first complete measurement of the β-decay strength distribution of _{17}^{45}Cl_{28} was performed at the Facility for Rare Isotope Beams (FRIB) with the FRIB Decay Station Initiator during the second FRIB experiment. The measurement i…
View article: Beta-strength and anti-neutrino spectra from Total Absorption Spectroscopy of a decay chain 142Cs and #8594;142Ba and #8594;142La
Beta-strength and anti-neutrino spectra from Total Absorption Spectroscopy of a decay chain 142Cs and #8594;142Ba and #8594;142La Open
View article: First Exploration of Monopole-Driven Shell Evolution above the N = 126 shell closure: new Millisecond Isomers in 213Tl and 215Tl
First Exploration of Monopole-Driven Shell Evolution above the N = 126 shell closure: new Millisecond Isomers in 213Tl and 215Tl Open
Isomer spectroscopy of heavy neutron-rich nuclei beyond the N=126 closed shell has been performed for the first time at the Radioactive Isotope Beam Factory of the RIKEN Nishina Center. New millisecond isomers have been identified at low e…
View article: <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>β</mml:mi></mml:math> decay of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi>Mg</mml:mi><mml:mprescripts/><mml:none/><mml:mn>36</mml:mn></mml:mmultiscripts></mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi>Al</mml:mi><mml:mprescripts/><mml:none/><mml:mn>36</mml:mn></mml:mmultiscripts></mml:math>: Identification of a <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>β</mml:mi></mml:math>-decaying isomer in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi>Al</mml:mi><mml:mprescripts/><mml:none/><mml:mn>36</mml:mn></mml:mmultiscripts></mml:math>
decay of and : Identification of a -decaying isomer in Open
For this work, the level structure of 36Al has been studied via β decay of 36Mg at the Facility for Rare Isotope Beams (FRIB) and the National Superconducting Cyclotron Laboratory (NSCL). A long-lived isomer in 3…
View article: Microsecond Isomer at the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>N</mml:mi><mml:mo>=</mml:mo><mml:mn>20</mml:mn></mml:math> Island of Shape Inversion Observed at FRIB
Microsecond Isomer at the Island of Shape Inversion Observed at FRIB Open
Excited-state spectroscopy from the first experiment at the Facility for Rare Isotope Beams (FRIB) is reported. A 24(2)-μs isomer was observed with the FRIB Decay Station initiator (FDSi) through a cascade of 224- and 401-keV γ rays in coi…
View article: Precision measurement of 65Zn electron-capture decays with the KDK coincidence setup
Precision measurement of 65Zn electron-capture decays with the KDK coincidence setup Open
View article: Improving fission-product decay data for reactor applications: part I—decay heat
Improving fission-product decay data for reactor applications: part I—decay heat Open
View article: Complete <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>β</mml:mi></mml:math>-decay patterns of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi mathvariant="normal">Cs</mml:mi><mml:mprescripts/><mml:none/><mml:mn>142</mml:mn></mml:mmultiscripts><mml:mo>,</mml:mo><mml:mmultiscripts><mml:mi mathvariant="normal">Ba</mml:mi><mml:mprescripts/><mml:none/><mml:mn>142</mml:mn></mml:mmultiscripts><mml:mo>,</mml:mo></mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi mathvariant="normal">La</mml:mi><mml:mprescripts/><mml:none/><mml:mn>142</mml:mn></mml:mmultiscripts></mml:math> determined using total absorption spectroscopy
Complete -decay patterns of and determined using total absorption spectroscopy Open
Background: The β decays of fission products produced in nuclear fuel are important for nuclear energy applications and fundamental science of reactor antineutrinos. In particular, nuclear reactor safety is related to the decay modes of ra…
View article: Microsecond Isomer at the N=20 Island of Shape Inversion Observed at FRIB
Microsecond Isomer at the N=20 Island of Shape Inversion Observed at FRIB Open
Excited-state spectroscopy from the first Facility for Rare Isotope Beams (FRIB) experiment is reported. A 24(2)-$μ$s isomer was observed with the FRIB Decay Station initiator (FDSi) through a cascade of 224- and 401-keV $γ$ rays in coinci…
View article: Development of digital electronics for the search of SHE nuclei using GARIS-II/III at RIKEN
Development of digital electronics for the search of SHE nuclei using GARIS-II/III at RIKEN Open
View article: Study of decay properties of Ba to Nd nuclei (A~160) relevant to the formation of the r-process rare-earth peak
Study of decay properties of Ba to Nd nuclei (A~160) relevant to the formation of the r-process rare-earth peak Open
Half-lifes ( T 1/2 ) of exotic neutron-rich isotopes of Ba, La, Ce, Pr, and Nd were measured at the RIKEN Nishina Center. The experimental setup consisted of the BigRIPS in-flight separator for ion selection identification, the Advance Imp…
View article: Average charge states of heavy ions in rarefied hydrogen
Average charge states of heavy ions in rarefied hydrogen Open
View article: New isotope <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi>Mc</mml:mi><mml:mprescripts/><mml:none/><mml:mn>286</mml:mn></mml:mmultiscripts></mml:math> produced in the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mmultiscripts><mml:mi>Am</mml:mi><mml:mprescripts/><mml:none/><mml:mn>243</mml:mn></mml:mmultiscripts><mml:mo>+</mml:mo><mml:mmultiscripts><mml:mi>Ca</mml:mi><mml:mprescripts/><mml:none/><mml:mn>48</mml:mn></mml:mmultiscripts></mml:mrow></mml:math> reaction
New isotope produced in the reaction Open
In this paper, we present results of the second experiment on the synthesis of Mc isotopes in the 243Am + 48Ca reaction performed at the gas-filled separator DGFRS-2 of the SHE Factory at JINR. Here, the new isotope <…
View article: Crossing <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi>N</mml:mi><mml:mo>=</mml:mo><mml:mn>28</mml:mn></mml:mrow></mml:math> Toward the Neutron Drip Line: First Measurement of Half-Lives at FRIB
Crossing Toward the Neutron Drip Line: First Measurement of Half-Lives at FRIB Open
New half-lives for exotic isotopes approaching the neutron drip-line in the vicinity of N∼28 for Z=12-15 were measured at the Facility for Rare Isotope Beams (FRIB) with the FRIB decay station initiator. The first experimental results are …
View article: Demonstration of the neutron tracking capability of NEXT array in time-of-flight measurements to improve energy resolution
Demonstration of the neutron tracking capability of NEXT array in time-of-flight measurements to improve energy resolution Open
Precise neutron-energy measurements are required to probe the nuclear structure effects of neutron-rich nuclei, where β-delayed neutron emission becomes a dominant decay mode. The Neutron dEtector with Xn Tracking (NEXT) array has been des…
View article: <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>β</mml:mi></mml:math> decay of neutron-rich <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi>Cu</mml:mi><mml:mprescripts/><mml:none/><mml:mn>76</mml:mn></mml:mmultiscripts></mml:math> and the structure of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi>Zn</mml:mi><mml:mprescripts/><mml:none/><mml:mn>76</mml:mn></mml:mmultiscripts></mml:math>
decay of neutron-rich and the structure of Open
In this work, the β decay of 76Cu to the levels of 76Zn was studied at the Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge National Lab (ORNL). A purified 76Cu beam was developed and data were …
View article: First experiment at the Super Heavy Element Factory: High cross section of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi>Mc</mml:mi><mml:mprescripts/><mml:none/><mml:mn>288</mml:mn></mml:mmultiscripts></mml:math> in the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mmultiscripts><mml:mi>Am</mml:mi><mml:mprescripts/><mml:none/><mml:mn>243</mml:mn></mml:mmultiscripts><mml:mo>+</mml:mo><mml:mmultiscripts><mml:mi>Ca</mml:mi><mml:mprescripts/><mml:none/><mml:mn>48</mml:mn></mml:mmultiscripts></mml:mrow></mml:math> reaction and identification of the new isotope <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi>Lr</mml:mi><mml:mprescripts/><mml:none/><mml:mn>264</mml:mn></mml:mmultiscripts></mml:math>
First experiment at the Super Heavy Element Factory: High cross section of in the reaction and identification of the new isotope Open
Here, we present results of the first experiment aimed at the synthesis of Mc isotopes in the 243Am+48Ca reaction performed at the new gas-filled separator DGFRS-2 online to the new cyclotron DC280 at the Super Heavy …
View article: Measuring the β-decay Properties of Neutron-rich Exotic Pm, Sm, Eu, and Gd Isotopes to Constrain the Nucleosynthesis Yields in the Rare-earth Region
Measuring the β-decay Properties of Neutron-rich Exotic Pm, Sm, Eu, and Gd Isotopes to Constrain the Nucleosynthesis Yields in the Rare-earth Region Open
The β -delayed neutron-emission probabilities of 28 exotic neutron-rich isotopes of Pm, Sm, Eu, and Gd were measured for the first time at RIKEN Nishina Center using the Advanced Implantation Detector Array (AIDA) and the BRIKEN neutron de…
View article: Investigation of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi>Ca</mml:mi><mml:mprescripts/><mml:none/><mml:mn>48</mml:mn></mml:mmultiscripts></mml:math>-induced reactions with <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi>Pu</mml:mi><mml:mprescripts/><mml:none/><mml:mn>242</mml:mn></mml:mmultiscripts></mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi mathvariant="normal">U</mml:mi><mml:mprescripts/><mml:none/><mml:mn>238</mml:mn></mml:mmultiscripts></mml:math> targets at the JINR Superheavy Element Factory
Investigation of -induced reactions with and targets at the JINR Superheavy Element Factory Open
Experiments using a 48Ca beam on 238U and 242Pu targets to produce superheavy nuclei were performed at the gas-filled separator DGFRS-2 online to the new cyclotron DC280 at the SHE Factory at JINR. The deca…
View article: Probing Optimal Reaction Energy for Synthesis of Element 119 from <sup>51</sup>V+<sup>248</sup>Cm Reaction with Quasielastic Barrier Distribution Measurement
Probing Optimal Reaction Energy for Synthesis of Element 119 from <sup>51</sup>V+<sup>248</sup>Cm Reaction with Quasielastic Barrier Distribution Measurement Open
Here, the quasielastic barrier distribution of 51V+248Cm was extracted by measuring the excitation function of quasielastic backscattering using a gas-filled recoil ion separator, GARIS-III. The obtained barrier distr…
View article: Deciphering <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi>Nb</mml:mi><mml:mprescripts/><mml:none/><mml:mn>98</mml:mn></mml:mmultiscripts></mml:math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>β</mml:mi></mml:math> decay with the Modular Total Absorption Spectrometer at ORNL
Deciphering decay with the Modular Total Absorption Spectrometer at ORNL Open
An assessment done under the auspices of the Organization for Economic Co-operation and Developement Nuclear Energy Agency (OECD-NEA) in 2007 suggested that the β decays of many abundantly produced fission products in nuclear reactors may …
View article: Determination of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>β</mml:mi></mml:math>-decay feeding patterns of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi>Rb</mml:mi><mml:mprescripts/><mml:none/><mml:mn>88</mml:mn></mml:mmultiscripts></mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi>Kr</mml:mi><mml:mprescripts/><mml:none/><mml:mn>88</mml:mn></mml:mmultiscripts></mml:math> using the Modular Total Absorption Spectrometer at ORNL HRIBF
Determination of -decay feeding patterns of and using the Modular Total Absorption Spectrometer at ORNL HRIBF Open
We report precise determination of ground-state feeding in the β decay of fission products is an important but challenging component in modeling reactor antineutrino flux and reactor decay heat. The Modular Total Absorption Spectrometer (M…