Charge resolution in the isochronous mass spectrometry and the mass of ${}^{51}$Co

Abstract

Isochronous mass spectrometry (IMS) of heavyion storage rings is a powerful tool for the mass measurements of short-lived nuclei. In IMS experiments, masses are determined through precision measurements of the revolution times of the ions stored in the ring. However, the revolution times cannot be resolved for particles with nearly the same mass-to-charge (m/q) ratios. To overcome this limitation and to extract the accurate revolution times for such pairs of ion species with very close m/q ratios, in our early work on particle identification, we analyzed the amplitudes of the timing signals from the detector based on the emission of secondary electrons. Here, the previous data analysis method is further improved by considering the signal amplitudes, detection efficiencies, and number of stored ions in the ring. A sensitive Z-dependent parameter is introduced in the data analysis, leading to a better resolution of ${}^{34}$Ar${}^{18+}$ and ${}^{51}$Co${}^{27+}$ with A/Z=17/9. The mean revolution times of ${}^{34}$Ar${}^{18+}$ and ${}^{51}$Co${}^{27+}$ are deduced, although their time difference is merely 1.8 ps. The uncorrected, overlapped peak of these ions has a full width at half maximum of 7.7 ps. The mass excess of ${}^{51}$Co was determined to be -27332(41) keV, which is in agreement with the previous value of -27342(48) keV.

arXiv comment8 pages, 6 figures

References in corpus (17)

• Heavy-Ion Storage Rings and Their Use in Precision Experiments with Highly Charged Ions
• Nuclear Physics Experiments with Ion Storage Rings
• Isochronous mass measurements of $T_z=-1$ $fp$-shell nuclei from projectile fragmentation of ${}^{58}$Ni
• Storage ring mass spectrometry for nuclear structure and astrophysics research
• Identification of the Lowest $T=2$, $J^{\pi =}{0}^{+}$ Isobaric Analog State in ${}^{52}$Co and Its Impact on the Understanding of $\beta$-Decay Properties of ${}^{52}$Ni
• Towards the full realization of the RIBLL2 beam line at the HIRFL-CSR complex
• Mass Measurements of Neutron-Deficient Y, Zr, and Nb Isotopes and Their Impact on $rp$ and $\nu p$ Nucleosynthesis Processes
• Masses of neutron-rich ${}^{52-54}$Sc and ${}^{54,56}$Ti nuclides: The $N=32$ subshell closure in scandium
• Direct mass measurements of neutron-rich ${}^{86}$Kr projectile fragments and the persistence of neutron magic number $N$ = 32 in Sc isotopes
• Particle identification and revolution time corrections for the isochronous mass spectrometry in storage rings
• Masses of ground and isomeric states of ${}^{101}$In and configuration-dependent shell evolution in odd-$A$ indium isotopes
• Characterization of a double Time-Of-Flight detector system for accurate velocity measurement in a storage ring using laser beams
• An improvement of isochronous mass spectrometry: Velocity measurements using two time-of-flight detectors
• Simultaneous measurement of beta-delayed proton and gamma emission of ${}^{26}$P for ${}^{25}$Al($p,\gamma$)${}^{26}$Si reaction rate
• The Masses of the $T_z=-3/2$ Nuclei ${}^{27}$P and ${}^{29}$S
• Mass measurements for $T_z=-2$ $fp$-shell nuclei ${}^{40}$Ti, ${}^{44}$Cr, ${}^{46}$Mn, ${}^{48}$Fe, ${}^{50}$Co and ${}^{52}$Ni
• A data analysis method for isochronous mass spectrometry using two time-of-flight detectors at CSRe

Cited by in corpus (1)

• Machine learning the nuclear mass