The Clover: a new generation of composite Ge detectors

Medium-spin states in neutron-rich83As and81As

“…The spectrometer contained 15 Cluster germanium detectors placed in the backward hemisphere with respect to the beam, 26 Clover germanium detectors located around 90 • and 30 tapered single-crystal germanium detectors located at forward angles. Each Cluster detector consists of seven closely packed large volume Ge crystals [16] and each Clover detector consists of four smaller Ge crystals [17].…”

Triaxial deformation and nuclear shape transition in192Au

“…If the gate is at a stretched E2 transition, the R DCO ratios are greater than 1.0 for E2 transitions, approximately 0.7 for stretched E1 or M1 dipole transitions, and for mixed M1+E2 transitions it takes values in-between. The Clover detectors, which are positioned at 90 • with respect to the beam in YRAST Ball spectrometer, were used as in-beam Compton polarimeters [24]. At this angle, the polarization is directly proportional to the experimental asymmetry, which is defined as A pol = (N ⊥ − N )/(N ⊥ + N ) where N and N ⊥ are the normalized counting rates observed respectively for the coincidences between the Ge crystal acting as scatterer and the horizontal absorber Ge crystal and between the scatterer and the vertical absorber.…”

Relative U235(n,γ) and (Allmond1, Bernstein2, Beausang3 et al. 2009Phys. Rev. C370200View full textAdd to dashboardCite

“…Particle data were taken with the Silicon Telescope Array for Reaction Studies (STARS) [6] consisting of three (∆E, E1, and E2) large-area, double-sided, annular Si detectors (segmented into rings, θ, and sectors, φ) configured in a ∆E − E telescope array at forward angles θ for ≈ 33 • − 41 • with respect to and symmetric about the beam axis (e.g., in azimuth, φ) and a single annular fission detector at backward angles θ back ≈ 31 • − 62 • with respect to and symmetric about the beam axis, φ. Coincident gamma-ray data were collected with the LivermoreBerkeley Array for Collaborative Experiments (LIBER-ACE) consisting of 5 Compton-suppressed HPGe clover detectors [20] arranged in 45 • increments within a single plane parallel to the beam axis. Figure 3 shows a schematic of the 235 U target and detector arrangement used in the present study.…”

“…The relative and absolute energy calibration of the ∆E − E telescope array is set by the following sources: (1) 17 O, and (4) onset of fission and neutron evaporation in the (d,p) channel at the 236 U fission barrier, B f ∼ 5 MeV, and neutron evaporation threshold, S n = 6.55 MeV, respectively. The total clover add-back resolution (where add-back allows for the addition of two prompt gamma rays in adjacent segments of a HPGe clover detector [20]) at 1000 keV is FWHM∼ 3 keV and the add-back singles peak efficiency at 1000 keV is γ−singles ∼ 1.1% (determined from a 152 Eu γ-ray calibration source). Further details of efficiency are discussed later.…”