The GREAT triggerless total data readout method

Abstract

Abstract-Recoil decay tagging (RDT) is a very powerful method for the spectroscopy of exotic nuclei. RDT is a delayed coincidence technique between detectors usually at the target position and at the focal plane of a spectrometer. Such measurements are often limited by dead time. This paper describes a novel triggerless data acquisition method, which is being developed for the gamma recoil electron alpha tagging (GREAT) spectrometer, that overcomes this limitation by virtually eliminating dead time.Our solution is a total data readout (TDR) method where all channels run independently and are associated in software to reconstruct events. The TDR method allows all the data from both target position and focal plane to be collected with practically no dead-time losses. Each data word is associated with a timestamp generated from a global 100-MHz clock. Events are then reconstructed in real time in the event builder using temporal and spatial associations defined by the physics of the experiment.

Lifetimes of intruder states in 186Pb, 188Pb and 194Po

“…They were used to provide the position and implantation time information of both the recoiling nuclei as well as their subsequent decay properties. Signals from all the detectors were recorded by employing the Total Data Readout (TDR) data acquisition system, comprising a triggerless system where all channels run independently [32]. In the TDR system, all the signals are time stamped by a global 100 MHz clock.…”

In-beam spectroscopy with intense ion beams: Evidence for a rotational structure in246Fm

“…The sampled data are then pipe-line processed using the Jordanov algorithm [16] to generate a trapezoid shape with rise and fall times of 3 µs and a plateau length of 1.5 µs. The TNT2D cards were incorporated into the Total Data Readout data acquisition system [17] with the time stamp being generated on a channel-bychannel basis with a constant-fraction discriminator algorithm. This reduces the dead time of the card to the pile-up resolution time, namely the sum of the lengths of the rise and plateau of the trapezoid.…”

Level structure above the 17+ isomeric state in Tm8369152

“…All registered detector signals were time stamped using a 100-MHz clock in the total data readout (TDR) acquisition system [15]. The FPGe detectors were used to detect the energies and timing of γ -ray events that had been delayed (E D γ ) with respect to the observed prompt γ rays (E P γ ) at the target position.…”