The Miniball spectrometer

Abstract

Abstract. The Miniball germanium detector array has been operational at the REX (Radioactive ion beam EXperiment) post accelerator at the Isotope Separator On-Line facility ISOLDE at CERN since 2001. During the last decade, a series of successful Coulomb excitation and transfer reaction studies have been performed with this array, utilizing the unique and high-quality radioactive ion beams which are available at ISOLDE. In this article, an overview is given of the technical details of the full Miniball setup, including a description of the γ-ray and particle detectors, beam monitoring devices and methods to deal with beam contamination. The specific timing properties of the REX-ISOLDE facility are highlighted to indicate the sensitivity that can be achieved with the full Miniball setup. The article is finalized with a summary of some physics highlights at REX-ISOLDE and the utilization of the Miniball germanium detectors at other facilities.

Experimental study of bound states in12Be through low-energy11Be(d,p)Johansen1, Bildstein2, Borge3 et al. 2013Phys. Rev. CSelf Cite283180View full textAdd to dashboardCite

“…The setup consisted of the MINIBALL germanium detector array [40,41] in combination with the T-REX silicon detector setup [42]. The T-REX was used to detect the light charged particles from the reaction.…”

Nuclear-structure studies of exotic nuclei with MINIBALL

“…A two dimensional position resolution of about 7.5 mm (FWHM) is obtained with the segmented MINIBALL HPGe detectors. A detailed description of the spectrometer is provided by [51][52][53][54]. A picture of the spectrometer and its surrounding infrastructure is shown in figure 1.…”

“…For these nuclei intriguing results related to dynamic and static octupole deformation were obtained [49]. A first review article on the reacceleration of radioactive beams at REX-ISOLDE, the instrumentation and the experimental techniques and the MINIBALL physics program was published in 2011 [50]; a recent comprehensive description of the MINIBALL spectrometer and its operation at REX-ISOLDE was given in [51].…”

Coulomb excitation of29,30Na: Mapping the borders of the island of inversion

“…After an A/q separation with A/q = 4.143 for 29 Na and A/q = 4.286 for 30 Na (both q = 7+) the radioactive beam was postaccelerated by the REX linear accelerator and delivered with a final beam energy of 2.85 MeV/nucleon onto the secondary target inside the highlyefficient MINIBALL setup [38]. The average intensities of the postaccelerated ion beams amounted to 2700(100) ions/s and 650(250) ions/s for 29 The scattered beam nuclei were detected by a CD-shaped, 500-μm-thick, double-sided silicon strip detector (DSSSD), consisting of four identical quadrants [38,39]. Each quadrant comprised 16 annular strips at the front side and 12 pairs of sector strips at the back side for identification and reconstruction of the trajectories of the scattered nuclei.…”

“…De-excitation γ rays following Coulomb excitation of projectile and target nuclei were detected by the MINIBALL γ -ray spectrometer, consisting of eight triple cluster detectors in close geometry, each containing three sixfold segmented HPGe crystals [38,40]. To calibrate the MINIBALL clusters and to determine their individual, energy-dependent efficiency down to 50 keV, 60 Co, 133 Ba, and 152 Eu sources were mounted onto the target frame at target position.…”