Proton response of CEPA4: A novel LaBr 3 (Ce)–LaCl 3 (Ce) phoswich array for high-energy gamma and proton spectroscopy

Search for beta-delayed proton emission from $$^{11}$$Be

“…The basic idea is as in the earlier experiments [6,7] to collect 11 Be samples, determine their intensity on-line via the γ-decays and measure the amount of produced 10 Be via a subsequent accelerator mass spectrometry (AMS) step. Samples collected at different settings of the ISOLDE mass separator allow checking the reproducibility of the result as well as testing for different sources of contamination.…”

“…A HPGe detector was positioned 632(2) mm downstream from the flange in continuation of the beam line direction. A LaBr 3 (Ce) and a CEPA4 (combined LaBr 3 (Ce) and LaCl 3 (Ce) [11]) detector were placed at either side of the chamber in the downstream direction in order not to block the line-of-sight to the HPGe detector, the distances from the flange of the chamber to the front edge of the LaBr 3 and the CEPA4 were 88 mm and 126 mm, respectively, corresponding to angles of 40-50 degrees from the beam line direction. The cylindrical LaBr 3 detector had a radius of 10 mm and a length of 20 mm, while the Fig.…”

“…1. The set-up: the 11 Be beam is coming from the left, passes several collimators and is collected on the Cu sample that is mounted on the end flange. The on-line gamma activity is recorded in a HPGe at zero degrees (far right) and in LaBrdetectors positioned at both sides.…”

“…Certain beta-delayed processes turn out [3] to occur only in near-dripline nuclei, the one we focus on here is beta-minus delayed proton emission. This process is only allowed for a few neutron-rich nuclei and was predicted [4] to have a very small branching ratio even for the most promising case, that of 11 Be. The first experiments [5,6,7] to look for this decay focussed on detecting the final nucleus 10 Be rather than the emitted proton.…”

“…An overview of the current state of knowledge on the beta decay of 11 Be was given in [6]. A recent experimental a email:kvr@phys.au.dk result [10] clarified the situation for the beta-delayed αdecay branch of 11 Be.…”