IPHC 2007 10 MS2 telescope beam test LG

Beam tests at the ALS and RHIC with a Mimostar-2 telescope: 

Beam tests at the ALS and RHIC with a Mimostar-2 telescope

STAR Detector at RHIC: 

STAR Detector at RHIC

HFT PIXEL Readout Functional Goals: 

HFT PIXEL Readout Functional Goals Triggered detector system fitting into existing STAR infrastructure (Trigger, DAQ, etc.) Deliver full frame events to STAR DAQ for event building at approximately the same rate as the TPC (1 KHz for DAQ1000). Reduce the total data rate of the detector to a manageable level (< TPC rate). Reliable, robust, cost effective, etc.

Mimostar Data Flow: 

Mimostar Data Flow System Goal: 10 Sensors / Ladder 33 Ladders 135M Pixel

Slide5: 

Data examined Per clock cycle Implemented in FPGA on daughter card Raster scan

Cluster Finder Efficiency: 

Cluster Finder Efficiency Real Data taken with MIMOSTAR2 detectors by IPHC Traditional ADC Sum Method 2 Threshold FPGA method Cut on the central pixel goes from 14 to 8 ADC counts (left to right) every 1 ADC. 1 ADC = 7.1 e-.

PIXEL Data Rates (1 KHz): 

PIXEL Data Rates (1 KHz) Rate @ R1 (2.5cm) = 52.9 / cm2 Rate @ R2 (6.5cm) = 10.75 / cm2 Rate @ R3 (7.5cm) = 8.76 / cm2 (at L = 1027) 2.5 hits / cluster 4 ms integration time Address data rate (no event format overhead) Average event size = 114 KB Data Rate = 114 MB/sec at 1KHz 59.6 MB/s L = 3 x 1027

Prototype 3 Sensor Telescope: 

Prototype 3 Sensor Telescope We tested the functionality of a prototype MIMOSTAR2 detector at the LBNL ALS and then in the environment at STAR during the last three weeks of the 2006-2007 run at RHIC. Our goal was to gather information on: Charged particle environment near the interaction region in STAR. Performance of our cluster finding algorithm. Performance of the MIMOSTAR2 sensors. Functionality of our interfaces to the other STAR subsystems. Performance of our hardware / firmware as a system. The noise environment in the area in which we expect to put the final PIXEL detector.

Telescope Electronics / RDO: 

Telescope Electronics / RDO STRATIX DAUGHTER CARD RORC SIU MimoStar2 chips on kapton cables MOTHER BOARD Acquisition Server (Linux) Control PC (Win)

Telescope Sensors and Mechanical Housing: 

Telescope Sensors and Mechanical Housing 3 MIMOSTAR2 chips mounted as close together as reasonably possible on low mass kapton cables in a telescope configuration.

Mimostar2 Telescope test at the ALS: 

Mimostar2 Telescope test at the ALS 1.2 GeV electrons at the ALS Booster Test Facility Important Due to un-terminated DAC pads on the sensor, our noise level was double the value achieved under ideal conditions at IPHC in France. IPHC =>11-15 electrons at 30º C LBL => 30-35 electrons at 28º C MPV = 49 (Standard) and 43 (Radtol) ADC counts at ~230 electrons

Efficiency and Accidental rates for ALS test: 

Efficiency and Accidental rates for ALS test Merged cluster data – typically 2-3 hits per cluster. Increased noise in sensors results in reduced performance.

Telescope Installed at STAR: 

Telescope Installed at STAR Magnet Pole Tip Electronics Box Beam Pipe Telescope head – 1.45 m from interaction point just below beam pipe.

STAR Prototype Run Results: 

STAR Prototype Run Results Typical CDS full frame event in one sensor. Clusters are clearly visible above the noise level. Measured charged particle flux was ~ 3.9 merged clusters per sensor (1.7 µs integration time, L=81026 cm-2s-1 ). Noise level of system in the STAR environment was 7.48 ADC counts, comparable to laboratory and ALS measurements. Prototype system integrated with STAR Trigger, slow control and run control sub-systems. Events delivered to DAQ standard RDO PC. TLD measured dose at head position, 325 rad over running time. This scales to an integrated dose of several hundred Krad / run.

Distribution of track angles in Mimostar2 telescope: 

Distribution of track angles in Mimostar2 telescope

Summary for beam runs: 

Summary for beam runs RDO system with data sparsification implemented and functional for Mimostar2 sensors. Prototype system characterized, but with increased noise. Fully functioning interfaces between our prototype detector and STAR detector infrastructure. Completed measurements of detector environment at STAR including induced electronic noise.

Slide17: 

fin