The STAR Vertex Position Detector

• Published in: Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment Vol. 759; pp. 23 - 28
• Main Authors: Llope, W.J., Zhou, J., Nussbaum, T., Hoffmann, G.W., Asselta, K., Brandenburg, J.D., Butterworth, J., Camarda, T., Christie, W., Crawford, H.J., Dong, X., Engelage, J., Eppley, G., Geurts, F., Hammond, J., Judd, E., McDonald, D.L., Perkins, C., Ruan, L., Scheblein, J., Schambach, J.J., Soja, R., Xin, K., Yang, C.
• Format: Journal Article
• Language: English
• Published: United States Elsevier B.V 21.09.2014; Elsevier
• Subjects: fast timing; NUCLEAR PHYSICS AND RADIATION PHYSICS; relativistic heavy ion collider; RHIC; STAR experiment; Time resolution; Vertex Position Detector; Time resolution; Vertex Position Detector; fast timing; RHIC; STAR experiment
• ISSN: 0168-9002; 1872-9576
• DOI: 10.1016/j.nima.2014.04.080

The 2×3 channel pseudo Vertex Position Detector (pVPD) in the STAR experiment at RHIC has been upgraded to a 2×19 channel detector in the same acceptance, called the Vertex Position Detector (VPD). This detector is fully integrated into the STAR trigger system and provides the primary input to the minimum-bias trigger in Au+Au collisions. The information from the detector is used both in the STAR Level-0 trigger and offline to measure the location of the primary collision vertex along the beam pipe and the event “start time” needed by other fast-timing detectors in STAR. The offline timing resolution of single detector channels in full-energy Au+Au collisions is ~100ps, resulting in a start time resolution of a few tens of picoseconds and a resolution on the primary vertex location of ~1cm.