Y. M. Xing

Identification of the Lowest T =2, Jπ =0+ Isobaric Analog State in 52Co and Its Impact on the Understanding of β-Decay Properties of52Ni

Masses of ^{52g,52m}Co were measured for the first time with an accuracy of ∼10  keV, an unprecedented precision reached for short-lived nuclei in the isochronous mass spectrometry. Combining our results with the previous β-γ measurements of ^{52}Ni, the T=2, J^{π}=0^{+} isobaric analog state (IAS) in ^{52}Co was newly assigned, questioning the conventional identification of IASs from the β-delayed proton emissions. Using our energy of the IAS in ^{52}Co, the masses of the T=2 multiplet fit well into the isobaric multiplet mass equation. We find that the IAS in ^{52}Co decays predominantly via γ transitions while the proton emission is negligibly small. According to our large-scale shell model calculations, this phenomenon has been interpreted to be due to very low isospin mixing in the IAS.

Electron field emission from SiC∕Si heterostructures by high temperature carbon implantation into silicon

A high-intensity electron field emission was obtained from a SiC∕Si heterostructure, which was formed by high temperature carbon implantation into silicon. Densely distributed sharp tips were easily obtained at the interface of the SiC∕Si heterostructure by post-implantation etching off the top Si. A low turn-on field of 2.6V∕μm was observed with samples formed by 160keV carbon implantation with a dose of 8.0×1017cm−2. The existence of the densely distributed small protrusions was considered as the main reason for efficient emission.

An improvement of isochronous mass spectrometry: Velocity measurements using two time-of-flight detectors

Abstract Isochronous mass spectrometry (IMS) in storage rings is a powerful tool for mass measurements of exotic nuclei with very short half-lives down to several tens of microseconds, using a multicomponent secondary beam separated in-flight without cooling. However, the inevitable momentum spread of secondary ions limits the precision of nuclear masses determined by using IMS. Therefore, the momentum measurement in addition to the revolution period of stored ions is crucial to reduce the influence of the momentum spread on the standard deviation of the revolution period, which would lead to a much improved mass resolving power of IMS. One of the proposals to upgrade IMS is that the velocity of secondary ions could be directly measured by using two time-of-flight (double TOF) detectors installed in a straight section of a storage ring. In this paper, we outline the principle of IMS with double TOF detectors and the method to correct the momentum spread of stored ions.

Stress current calculation of stacked dielectrics in time dependent dielectric breakdown

This article presents a simple method for calculating the stress current in accelerated test of time dependent dielectric breakdown of stacked dielectrics. By replacing an energy barrier of arbitrary shape with a series of rectangular energy barriers and resolving rigorously the Schrodinger equation in each regions, interfaces and variations of electron effective masses in different dielectrics have been analyzed. Our calculations fit experimental data well. The method is applicable in this reliability study aimed at failure mechanism detection and prediction.

Mass measurements of neutron-deficient Y, Zr, and Nb isotopes and their impact on rp and νp nucleosynthesis processes

Abstract Using isochronous mass spectrometry at the experimental storage ring CSRe in Lanzhou, the masses of 82Zr and 84Nb were measured for the first time with an uncertainty of ∼10 keV, and the masses of 79Y, 81Zr, and 83Nb were re-determined with a higher precision. The latter are significantly less bound than their literature values. Our new and accurate masses remove the irregularities of the mass surface in this region of the nuclear chart. Our results do not support the predicted island of pronounced low α separation energies for neutron-deficient Mo and Tc isotopes, making the formation of Zr–Nb cycle in the rp-process unlikely. The new proton separation energy of 83Nb was determined to be 490(400) keV smaller than that in the Atomic Mass Evaluation 2012. This partly removes the overproduction of the p-nucleus 84Sr relative to the neutron-deficient molybdenum isotopes in the previous νp-process simulations.

Masses of the Tz = −3/2 nuclei 27P and 29S

Isochronous mass spectrometry has been applied in the storage ring CSRe to measure the masses of the

Application of Isochronous Mass Spectrometry for the study of angular momentum population in projectile fragmentation reactions

T_z=-3/2

High-precision QEC values of superallowed 0+ → 0+β-emitters 46Cr, 50Fe and 54Ni

nuclei

Half-life measurement of short-lived 94m44 Ru44+ using isochronous mass spectrometry

^{27}

Influence of nitrogen element on total-dose radiation response of high-k Hf-based dielectric films

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