The PHENIX Forward Silicon Vertex Tracker Eric J. Mannel IEEE NSS/MIC October 29, 2013

The PHENIX Experiment 2 Counter-circulating rings, 3.8Km circumference Energies: – Up to 200 GeV/Nucleon A+A – Up to 510 GeV polarized p+p Understand the source of proton spin Study the properties of the Quark-Gluon plasma 10/29/2013E.J. Mannel, BNL2

The PHENIX Detector FVTX for forward tracking Muons and Hadrons in the forward regions – FVTX – Mu ID – Mu Trackers – RPCs Hadrons, photons and electrons in central arms – VTX, Drift, and Pad chambers for charged particle tracking. – Ring Imaging Cerenkov and electromagnetic calorimeter for electron ID 10/29/2013E.J. Mannel, BNL3

The Physics of the FVTX Single Muons: Precision heavy flavor and hadron measurements at forward rapidity Separation of charm and beauty W background rejection improved Dimuons: Direct measurement of bottom via B  J/  Separation of J/  from  ’ with improved resolution. Direct measurement of c-cbar events via  +  - becomes possible Physics: Precise heavy flavor measurements of R AA and flow. Detection of  ’ plus heavy quark allows detailed understanding of vector meson production and modification Precise gluon polarization and sea quark measurements over large x range 10/29/2013E.J. Mannel, BNL4

The FVTX Detector Consists of 2 end-caps. 4 planes of silicon mini-strip sensors per end-cap. Covers – 1.2 < |  | < 2.2 – 2  in  –  cm < | z | < 38 cm Resolution: – Hit ~20  m – DCA < 200  m Muon rejection from decays of  ’s and K  and K 0 L. Identify decays of open heavy flavor particles by displaced vertices 10/29/2013E.J. Mannel, BNL5

Wedge Sensor Module Silicon Sensors: – Contains 2  segments – Strip length 3.4 mm to 11.5 mm, Radial pitch: 75  m – Covers in  with an angle of with respect to the centerline. – p-implants on 320  m thick n- type substrate. – AC coupled with 1.5 M  polysilicon resistors to bias voltage. – 2 p-implant guard rings with n + surround between guard rings and sensor edges. FPHX Chip Design – Custom 128-channel ASIC, trigger-less, data push design. – Integrator/shaper stage – Programmable parameters (gain, threshold, rise/fall time, …) – 3 bit ADC, Time and Channel ID – Process up to 4 hits in 4 RHIC beam crossings, ~424 nSec – 2 LVDS Serial output lines at 200 MHz – Radiation hard by design – Designed at FNAL 10/29/2013E.J. Mannel, BNL6

Wedge Sensor Modules (2) 10/29/2013E.J. Mannel, BNL7

Read Out Card (ROC) Primary Functions: – Receive, combine and synchronize data from 16 Wedges. – Transmit data to Front End Modules in counting room – Process slow control commands – Provide calibration circuitry. Hardware: – 4 ACTEL A3PE300-FG896 FPGAs for data processing – bit Serializer/Deserializer chips (TLK 2711) – 4 12 channel fiber optic transmitters 10/29/2013E.J. Mannel, BNL8

Front End Module (FEM) Primary functions: – Receive data from ROCs and sort date according to time stamp – Buffer data for last 64 beam crossings – Upon LVL1 trigger decision, send corresponding data to PHENIX DAQ system. – Process slow control commands Hardware: – Single Xilinx Virtex-4 FPGA (XC4VSX55) for data processing – channel optical receivers – Internal clock speed for reading/writing data is 300 MHz to minimize latencies. 10/29/2013E.J. Mannel, BNL9

Current Status Engineering run in 2012 (PHENIX Run-12) – Fully installed prior to start of run – Full commissioning with greater then 80% of the channels operational. – Physics data taken during the second half of the run First Physics run in 2013 (PHENIX Run-13) – Fully functional at start of run (> 95% of channels operational) – Low failure rate during the run, < 1% of the channels, with most failures recovered during maintenance periods. Currently undergoing routine maintenance in preparation for PHENIX Run-14 (January 2014 expected start) 10/29/2013E.J. Mannel, BNL10

FVTX Performance (1) Timing – Compare FVTX hit time relative to collision time – Vary the FVTX trigger with respect to the RHIC beam clock – Most hits fall in a 30nSec wide window – 2 timing configurations used, 2 BCO (~212nSec) for low intensity heavy ion running and 1 BCO (106nSec) for high intensity p-p running 10/29/2013E.J. Mannel, BNL11

FVTX Performance (2) Hit Efficiency – Use p+p data (low occupancy events) – Form tracks using hits in 3 planes – Project track into 4 th plane and look for corresponding hit. – Hit efficiency for station 2 as a function of phi – Overall efficiency is > 95%. No correction for dead channels. Low efficiency in north arm is due to known hardware failure. 10/29/2013E.J. Mannel, BNL12

FVTX Performance (3) Alignment and Residuals – Use magnet off data (straight line tracks) – Match tracks found in the PHENIX muon system to FVTX tracks (p > 3 GeV/c) using 3 stations. – Calculate the residual for the 4 th station by projecting to the 4 th station and using the nearest hit – Average detector resolution is ~26  m 10/29/2013E.J. Mannel, BNL13

FVTX Performance (4) Electronic Noise – Determined periodically. – Scan discriminator threshold with changing amplitude pulses – Noise level characterized by broadening of the hit efficiency threshold – Fit distribution with a normal cumulative distribution function – Noise level parameterized by the width 10/29/2013E.J. Mannel, BNL14

Conclusions FVTX Detector successfully installed for PHENIX RUN-12 Single particle hit efficiencies > 95% Hit position resolution < 30  m Electronic noise level below 500 electrons First physics results in preparation for publication. 10/29/2013E.J. Mannel, BNL15

Acknowledgements The FVTX Group: Columbia University, Charles University, Brookhaven National Laboratory, Dapnia CEA Saclay, Georgia State University, Institute of Physics, Academy of Sciences of the Czech Republic, Los Alamos National Laboratory, New Mexico State University, University of New Mexico Thanks to the technical staff from the SiDet Facility at Fermi National Laboratory for their assistance during the assembly of the wedge modules and the staff at LLNL for production of the carbon composite components. Special thanks to the technical staffs of Brookhaven National Laboratory and Los Alamos National Laboratory. 10/29/2013E.J. Mannel, BNL16