A position-sensitive Schottky Cavity Doublet(SCD)was developed to enhance the accuracy of isochronousmass measurement at the Rare Radio-Isotope Ring(R3)at RIBF-RIKEN,Japan.The aim is to increase theaccuracy of positio...A position-sensitive Schottky Cavity Doublet(SCD)was developed to enhance the accuracy of isochronousmass measurement at the Rare Radio-Isotope Ring(R3)at RIBF-RIKEN,Japan.The aim is to increase theaccuracy of position measurement,which is used to correct the momentum spread,thus reducing the uncertainty inthe mass determination.The detector comprises a cylindrical reference cavity and elliptical position-sensitive cavity,which uses an offset beam-pipe to create a relation between the Schottky power and horizontal position.The uncertaintyin the power response can be improved by minimizing free parameters inside the power equation,providing asecond-order correction for the position determination.This requires a large dispersion and momentum spread to effectivelycharacterize the SCD acceptance,which simulations show is achieved when using^(76)Zn as a reference isotope.A key parameter to minimize is uncertainty of the impedance map,which relates power to position in the ellipticalcavity.We find that an uncertainty in impedance of 0.3Ωresults in a precision equal to that of the current massmeasurement method.Additionally,measuring momentum with the SCD enables the removal of other detectorsfrom the beam-line,which drastically reduces the yield of high-Z beams via charge-change interactions.展开更多
基金support from the State of Hesse within the Research Cluster ELEMENTS(project ID 500/10.006)。
文摘A position-sensitive Schottky Cavity Doublet(SCD)was developed to enhance the accuracy of isochronousmass measurement at the Rare Radio-Isotope Ring(R3)at RIBF-RIKEN,Japan.The aim is to increase theaccuracy of position measurement,which is used to correct the momentum spread,thus reducing the uncertainty inthe mass determination.The detector comprises a cylindrical reference cavity and elliptical position-sensitive cavity,which uses an offset beam-pipe to create a relation between the Schottky power and horizontal position.The uncertaintyin the power response can be improved by minimizing free parameters inside the power equation,providing asecond-order correction for the position determination.This requires a large dispersion and momentum spread to effectivelycharacterize the SCD acceptance,which simulations show is achieved when using^(76)Zn as a reference isotope.A key parameter to minimize is uncertainty of the impedance map,which relates power to position in the ellipticalcavity.We find that an uncertainty in impedance of 0.3Ωresults in a precision equal to that of the current massmeasurement method.Additionally,measuring momentum with the SCD enables the removal of other detectorsfrom the beam-line,which drastically reduces the yield of high-Z beams via charge-change interactions.
