The FVTX detector is part of a silicon detector upgrade to the PHENIX experiment at Brookhaven National Laboratory.

The PHENIX collaboration performs basic research with high energy collisions of heavy ions and protons. PHENIX seeks to understand the quark gluon plasma, a state of matter thought to exist shortly after the big bang. PHENIX also explores quantum chromodynamics and the quantum spin properties of the proton. The experiment is housed in the Relativistic Heavy Ion Collider, the only spin-polarized proton-proton collider in the world.

My contributions to FVTX spanned elementary particle physics analysis, FPGA-based electronics, modeling detector geometry in code, and testing silicon detectors. Below are highlights of my work.

Software

• Collaborator: Aaron Key, Graduate Student, UNM

The basic hardware unit of FVTX is called a wedge. Each wedge is comprised of a silicon strip detector and a “high-density interconnect,” a multi-layered flex circuit board providing power and readout capabilities. Connecting the analog output of the silicon to the readout on the HDI are 26 custom readout chips, each of which have multiple, adjustable parameters controlling their operation. The GUI we designed communicates with the readout chips from an individual basis up to a detector-wide basis, allowing detailed adjustment of data acquisition. The GUI was written in Python using the Tkinter module.

• Features:
  • Integration with FPGA-based electronics.
  • Live propagation of visual cues to all levels of the GUI indicating changes not written to the FVTX hardware.

Hardware

• Supervisor: Sergey Butsyk, Postdoctoral Fellow, UNM
• Collaborator: Aaron Key, Graduate Student, UNM

The final FVTX detector will utilize a complex chain of electronics, processing data and providing two-way communication and control. Building an electronics test stand, we created and debugged the firmware necessary for interfacing with the GUI discussed above. We also finalized the communication chain of the built-in calibration capabilities of the FVTX detector.

Silicon Detector Testing

Using LabVIEW and a probe station, we verified quality metrics provided by Hamamatsu Photonics for each silicon detector ordered.

Detector Geometry Modeling

• Collaborator: Hubert van Hecke, Staff Physicist, Los Alamos National Laboratory

Part of the FVTX development process necessitated simple geometric computer modeling of each piece of the final detector. Using GEANT 3, a toolkit for FORTRAN, we created a simplified detector model in code. GEANT models integrate with particle collision modeling software, allowing studies of detector materials’ effects the collection of particle physics data. The model mirrors the final, surveyed geometry of FVTX, accounting for minute positioning changes not present in engineering specifications.