First application of combined isochronous and Schottky mass spectrometry: Half-lives of fully ionized Cr24+49 and Fe26+<

Abstract

Lifetime measurements of β -decaying highly charged ions have been performed in the storage ring CSRe by applying the isochronous Schottky mass spectrometry. The fully ionized 49 Cr and 53 Fe ions were produced in projectile fragmentation of 58 Ni primary beam and were stored in the CSRe tuned into the isochronous ion-optical mode. The new resonant Schottky detector was applied to monitor the intensities of stored uncooled 49 Cr 24+ and 53 Fe 26+ ions. The extracted half-lives T 1/2 ( 49 Cr 24+ ) = 44.0(27) min and T 1/2 ( 53 Fe 26+ ) = 8.47(19) min are in excellent agreement with the literature half-life values corrected for the disabled electron capture branchings. This is an important proof-of-principle step towards realizing the simultaneous mass and lifetime measurements on exotic nuclei at the future storage ring facilities. 29.20.db

Progress on internal gas-jet target nuclear reaction at the HIRFL-CSR

“…自2007年建 成以来, 被广泛应用于测量原子核质量 [25,26] 和离子-原 子分子碰撞谱学 [27] . 为拓展兰州重离子冷却储存环国 家实验室的研究领域, 中国科学院近代物理研究所自 CSRe直线段分别对称地装配着电子冷却装置 [28] 和气 体内靶系统 [29] , 通过前者提供的单能电子束可减小 [25,26] , 便于开展高电荷态离子衰变寿命的直接测 量 [30] . 储存束高的循环频率能在一定程度上弥补气体 内靶靶密度低的缺陷, 提高反应亮度 [17] .…”

Heavy-ion storage rings and their use in precision experiments with highly charged ions

“…Conventionally, the mass spectrometry applied to electron cooled beams is called Schottky mass spectrometry (SMS), getting part of the name from the Schottky-noise diagnostics employed to measure the revolution frequencies of the stored ions, see Section 3.3. This, however, is no longer strictly true since the cavity-based Schottky pick-ups were shown to be fast enough to operate also in the isochronous mass spectrometry described below [130,131]. The decay curve of the short lived isomeric state of 207m Tl 81+ as measured by time-resolved Schottky mass spectrometry, see Section 6.2.…”

“…Decay studies of highly charged ions are routinely performed at the ESR. First measurements were conducted in the CSRe [195]. Storage rings were intensively used to investigate electromagnetic transitions and first studies of α-decays were performed [196].…”

Denoising scheme based on singular-value decomposition for one-dimensional spectra and its application in precision storage-ring mass spectrometry

“…In certain cases, the integral peak area is of the experimental interest, from which the particle number can be inferred [56,58]. This is a prior step for, e.g., the measurement of the particle's lifetime [59], or the calibration of the particle's position [60]. Therefore, a proper deduction of the background is of the experimental importance.…”