Gary Sleege

SGARFACE: a novel detector for microsecond gamma ray bursts

The Short GAmma Ray Front Air Cherenkov Experiment (SGARFACE) is operated at the Whipple Observatory utilizing the Whipple 10 m -ray telescope. SGARFACE is sensitive to -ray bursts of more than 100 MeV with durations from 100 ns to 35µs and provides a fluence sensitivity as low as 0.8 rays per m 2 above 200 MeV (0.05 rays per m 2 above 2 GeV) and allows to record the burst time structure.

A high mass trigger for the E864 experiment at the AGS accelerator

Abstract The E864 experiment at the AGS is designed to carry out high sensitivity searches for a variety of possible new particles using relativistic heavy ion Au beams on Pb and Pt targets. In order to reach the desired sensitivities, a level-2 “late energy” trigger was built to select events in which a heavy particle is detected in a hadronic calorimeter with deposited energy and time-of-flight from the target exceeding preset values. The physics motivation for the trigger is discussed and and details of its hardware and software design are given. Performance results from recent E864 data taking runs are presented.

The PHENIX Level-1 Trigger system

The PHENIX detector at the Relativistic Heavy Ion Collider (RHIC) will study the dynamics of ultra-relativistic heavy ion collisions and search for exotic states of matter, most notably the quark gluon plasma (QGP). Substantial event selectivity is needed at RHIC to enhance interesting events relative to more common ones and to satisfy the requirements of the data acquisition system. The first on-line screening is achieved by the Level-1 Trigger. The Level-1 Trigger is a beamclock parallel-pipeline system that uses six Local Level-1 (LL1) algorithms pertaining to the six fastest PHENIX subdetectors, followed by a Global Level-1 (GL1) system that processes encoded LL1 reduced-bit data to issue up to 128 triggers. The GLI system is also responsible for organizing the partitioned running of the PHENIX detector. The LL1 algorithms operate on raw data to produce a first estimate of the number of electrons, photons, muons and hadrons as well as the transverse energy, event multiplicity, interaction time and vertex. The latency of the entire system is less than 40 beam crossings. The Level-1 Trigger is implemented using custom-designed 9U VME-P format boards.

PHENIX Level-1 Trigger systems for RHIC run-3

The PHENIX detector at the Relativistic Heavy Ion Collider (RHIC) will study the dynamics of ultra-relativistic heavy ion collisions and search for exotic states of matter, most notably the Quark Gluon Plasma (QGP). Substantial event selectivity is needed at RHIC to enhance interesting events relative to more common ones and to satisfy the requirements of the data acquisition system. The first on-line screening is achieved by the Level-1 Trigger. The Level-1 Trigger is a beam-clock parallel-pipeline system that uses Local Level-1 (LL1) algorithms pertaining to the fastest PHENIX subdetectors, followed by a Global Level-1 (GL1) system that processes encoded LL1 reduced-bit data to issue up to 32 triggers. In this paper we discuss a new set of LL1 trigger systems that will be deployed for the third RHIC run. These new trigger systems utilize the same basic hardware designed around commercial FPGA logic in order to provide a common platform for a wide variety of physics triggers.

PHENIX trigger system

Abstract A two level trigger system has been implemented in the PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC). Level 1 trigger system (LVL1) processes the reduced data from a part of the detector subsystems in parallel and makes a decision on each beam crossing. For each accepted event the information from LVL1 is added to the detector data stream. A detector partitioning mechanism accomplished in LVL1 permits to operate PHENIX both as a whole detector (single partition) as well as a group of different combinations of the detector subsystems (multiple partitions). The Level 2 trigger system (LVL2) makes a fast analysis of each accepted event and decides if its data have to be stored or to be discarded. A description of the components and operation of the PHENIX trigger system is presented in this article.