Identification and Separation of Radioactive Isotope Beams by the BigRIPS Separator at the RIKEN RI Beam Factory

Abstract

We have developed a method for achieving excellent resolving power in in-flight particle identification of radioactive isotope (RI) beams at the BigRIPS fragment separator at the RIKEN Nishina Center RI Beam Factory (RIBF). In the BigRIPS separator, RI beams are identified by their atomic number Z and mass-to-charge ratio A/Q which are deduced from the measurements of time of flight (TOF), magnetic rigidity (Brho) and energy loss (delta-E), and delivered as tagged RI beams to a variety of experiments including secondary reaction measurements. High A/Q resolution is an essential requirement for this scheme, because the charge state Q of RI beams has to be identified at RIBF energies such as 200-300 MeV/nucleon. By precisely determining the Brho and TOF values, we have achieved relative A/Q resolution as good as 0.034% (root-mean-square value). The achieved A/Q resolution is high enough to clearly identify the charge state Q in the Z versus A/Q particle identification plot, where fully-stripped and hydrogen-like peaks are very closely located. The precise Brho determination is achieved by refined particle trajectory reconstruction, while a slew correction is performed to precisely determine the TOF value. Furthermore background events are thoroughly removed to improve reliability of the particle identification. In the present paper we present the details of the particle identification scheme in the BigRIPS separator. The isotope separation in the BigRIPS separator is also briefly introduced.

References in corpus (4)

• Identification of 45 New Neutron-Rich Isotopes Produced by In-Flight Fission of a 238U Beam at 345 MeV/nucleon
• Development of Parallel Plate Avalanche Counter PPAC for BigRIPS fragment separator
• Production of very neutron-rich nuclei with a 76Ge beam
• Extraction of 3D field maps of magnetic multipoles from 2D surface measurements with applications to the optics calculations of the large-acceptance superconducting fragment separator BigRIPS

Cited by in corpus (26)

• ${}^{78}$Ni revealed as a doubly magic stronghold against nuclear deformation
• The Neutron-Rich Edge of the Nuclear Landscape. Experiment and Theory
• How Robust is the N = 34 Subshell Closure? First Spectroscopy of ${}^{52}$Ar
• Production cross section measurements of radioactive isotopes by BigRIPS separator at RIKEN RI Beam Factory
• Two-proton emission and related phenomena
• Conceptual design of the BRIKEN detector: A hybrid neutron-gamma detection system for nuclear physics at the RIB facility of RIKEN
• New neutron-deficient isotopes from ${}^{78}$Kr fragmentation
• First application of mass measurement with the Rare-RI Ring reveals the solar r-process abundance trend at A=122 and A=123
• $\beta$-Decay Half-Lives of 55 Neutron-Rich Isotopes beyond the N=82 Shell Gap
• Extraction of 3D field maps of magnetic multipoles from 2D surface measurements with applications to the optics calculations of the large-acceptance superconducting fragment separator BigRIPS
• Nuclear structure of 140Te with N = 88: Structural symmetry and asymmetry in Te isotopes with respect to the double-shell closure Z = 50 and N = 82
• Structure of 13Be probed via quasi-free scattering
• Is Seniority a Partial Dynamic Symmetry in the First $\nu g_{9/2}$ Shell?
• Simultaneous investigation of the $\mathbf{T}=1({\mathbf{J}}^{\pi }=0^{+})$ and $\mathbf{T}=0({\mathbf{J}}^{\pi }=9^{+})$ $\beta$ decays in ${}^{70}$Br
• Segmented YSO scintillation detectors as a new $\beta$-implant detection tool for decay spectroscopy in fragmentation facilities
• Beta decay of the very neutron-deficient ${}^{60}$Ge and ${}^{62}$Ge nuclei
• Investigation of the ground-state spin inversion in the neutron-rich 47,49Cl isotopes
• A First Glimpse at the Shell Structure beyond ${}^{54}$Ca: Spectroscopy of ${}^{55}$K, ${}^{55}$Ca, and ${}^{57}$Ca
• Intruder configurations in ${}^{29}$Ne at the transition into the island of inversion: Detailed structure study of ${}^{28}$Ne
• Spectroscopy of deeply bound orbitals in neutron-rich Ca isotopes
• Persistence of the $Z=28$ shell gap in $A=75$ isobars: Identification of a possible $(1/2^{-})$ $\mu$s isomer in ${}^{75}$Co and $\beta$ decay to ${}^{75}$Ni
• High-rate axial-field ionization chamber for particle identification of radioactive beams
• Spectroscopy of ${}^{52}$K
• The beta decay of Tz=-2 64Se and its descendants: the T=2 isobaric multiplet
• First Extraction of the Matter Radius of ${}^{132}$Sn via Proton Elastic Scattering at 200 MeV/Nucleon
• $\beta$-decay spectroscopy of neutron-deficient nuclei