Miniball experiment

The Miniball experiment is a gamma-ray spectroscopy setup regularly located in the ISOLDE facility at CERN, along with other locations including GSI, Cologne, PSI and RIKEN (HiCARI). Miniball is a high-resolution germanium detector array, specifically designed to work with low-intensity radioactive ion beams post-accelerated by HIE-ISOLDE (High Intensity and Energy-ISOLDE), to analyse gamma radiation emitted by short-lived nuclei. Due to six-fold detector segmentation, Miniball offers a superior Doppler-correction capability with respect to conventional gamma-ray spectrometers using unsegmented detectors. The array has been used for successful Coulomb-excitation and transfer-reaction experiments with exotic beams. Results from Miniball experiments have been used to determine and probe nuclear structure.

Miniball has been operational at the REX-ISOLDE (Radioactive ion beam EXperiment-ISOLDE) post accelerator at CERN since 2001. In 2015, it became part of the HIE-ISOLDE project, connected via the XT01 beamline. It was the first fully operational germanium gamma-ray spectrometer capable of determining spatial coordinates of the gamma-ray interaction points within the detector volume using pulse shape analysis.