iCAPS, the integrated Cologne Argonne Plunger Setup

Plunger devices are used worldwide to measure the lifetime of excited nuclear states on the order of hundreds of femto- to picoseconds. Deduced transition probabilities are used to test and refine nuclear models. A new very compact plunger device has been built, which retains the efficiency of detector setups at Argonne National Laboratory (ANL). The current setups for gamma-ray spectroscopy at ANL are Gammasphere and GRETINA. They are world-class in their efficiency and can be combined with ancillary particle detectors. For example, Neutron Shell is available for neutron detection and is placed outside the reaction chamber, whereas charged-particle detectors like Microball have to be placed around the target inside the vacuum chamber. The construction approach allows to simultaneously accommodate large area charged-particle-detector arrays to the plunger device. When moving to more and more exotic nuclei via weak reaction channels, the channel selectivity using ancillary detectors becomes the key ingredient for successfully untangling these rare events from other stronger reaction channels. The talk will cover design constrains as well as features like an active feedback system to compensate for beam induced changes of the target to degrader distance.