The STAR Photon Multiplicity Detector
Download
1 / 25

The STAR Photon Multiplicity Detector - PowerPoint PPT Presentation


  • 57 Views
  • Uploaded on

The STAR Photon Multiplicity Detector. Supriya Das, VECC Kolkata For The STAR PMD Collaboration Junior’s Day STAR Collaboration Meeting, BNL - 2003. Outline of the talk: Physics goals Working principle of the detector Design and fabrication aspects Test results Installation

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' The STAR Photon Multiplicity Detector' - marv


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

The STAR Photon Multiplicity Detector

Supriya Das, VECC Kolkata

For

The STAR PMD Collaboration

Junior’s Day

STAR Collaboration Meeting, BNL - 2003

  • Outline of the talk:

  • Physics goals

  • Working principle of the detector

  • Design and fabrication aspects

  • Test results

  • Installation

  • DAQ, Trigger and Slow control

  • Simulation and offline reconstruction software

  • Summary

Supriya Das : Junior’s Day, STAR Collaboration Meeting, BNL


What does it do?

We measure the multiplicity and spatial distribution of photons

(h,f,dN/dh etc) to study:

  • The azimuthal anisotropy to determine the reaction plane and flow as the probes of thermalization.

  • The event by event fluctuations in global observables like multiplicity and pseudorapidity distributions following critical phenomena near phase boundary.

  • The distribution of Ng and Ng/Nch with full azimuthal coverage ( the charged particles info will be taken from FTPC), looking for signals of chiral symmetry restoration (e.g. DCC).

Supriya Das : Junior’s Day, STAR Collaboration Meeting, BNL


Recollection from past…

Scintillator + CCD readout detector sitting

21.5 meters from the vertex covering

h = 2.9 to 4.2

  • Observation of collective flow

  • Phys. Lett. B403 (1997) 390.

  • Scaling of particle production:

  • Phys. Lett. B458 (1999) 422.

  • DCC Search:

  • Phys. Lett. B420 (1998) 169

  • Phys.Rev.C64:011901,2001

  • Fluctuations:

  • Phys. Rev. C, May 2002

Supriya Das : Junior’s Day, STAR Collaboration Meeting, BNL


How does it work?

  • Preshower detector :

  • 3X0 Pb convertor sandwiched between two

  • planes of segmented gas detectors.

  • Charged particle gives single cell signal in

  • both the planes, photon gives restricted

  • shower signal on the second plane

  • Two planes CPV+Preshower

  • Gas detector of hexagonal cells

  • Cell cross section : 1.0 cm2

  • Cell depth : 0.8 cm

  • Gas used: Ar+CO2 in 70:30

  • Total number of channels : 82,944

  • Distance from vertex : 550 cm

  • h coverage: 2.3 – 3.8

  • Area of the detector : 4.2 m2

PreShower

CPV

Supriya Das : Junior’s Day, STAR Collaboration Meeting, BNL


Different features of PMD

  • One Unit Module has 576 cells.

  • Different Supermodules has different number

  • of unit modules (4,6,9 etc.) depending on the

  • position on the detector

  • Each plain has 12 Supermodules 144

  • unit modules

  • Supermodules are Gas tightand HV isolated

  • Whole detector can be separated in two

  • halves

Supriya Das : Junior’s Day, STAR Collaboration Meeting, BNL


Single Cell Design

The single cells (shown above) have solder coating on the outer surface. They are assembled on a special jig (shown on the right) and fused together under controlled heat.

  • Cathode Material: 0.2mm thick copper sheet

  • Anode wire: 20 mm gold plated Tungsten

  • Anode wire Tension : 25 grams

  • End caps: standard 1.6 mm thick FR4 PCB

Supriya Das : Junior’s Day, STAR Collaboration Meeting, BNL


Unit Module construction

Unit Module

Components

  • Each unit module contains

  • 24x24 array of cells (576)

  • Size of unit module:

  • Rhombus of side 255 mm

  • Weight of unit module: 700 gm

Gas - 4 board plugged

onto the connector

Supriya Das : Junior’s Day, STAR Collaboration Meeting, BNL


STAR PMD Supermodule assembled in Laboratory

Supriya Das : Junior’s Day, STAR Collaboration Meeting, BNL


Front-end Electronics

The chip

Test board for GASSIPLEX

The front-end electronics for processing PMD signals uses

16-channelGASSIPLEXchips.

Gassiplex Chip Testing

10,000 chips have been tested for the full functionality of each channel.

Supriya Das : Junior’s Day, STAR Collaboration Meeting, BNL


Translator Board:

Needed to shift the logic level of the control signals (CLK, CLR

and T/H) from fast NIM to that of the GASSIPLEX chips.

  • Gas – 4 Boards:

  • Contains 4 GASSIPLEX boards and necessary

  • discrete components.

  • Two protection boards with twin series diodes for each

  • channel is also plugged in.

Buffer board:

Needed for the impedance matching of the analog signal and

the input impedance of the ADC in C-RAMS.

Different Front end boards

Supriya Das : Junior’s Day, STAR Collaboration Meeting, BNL


Supermodule under test in laboratory

  • Tests performed on the

  • Supermodule:

  • Gas leak test

  • HV test

  • Pedestal with FEE boards

  • Signal with cosmic muons

Supriya Das : Junior’s Day, STAR Collaboration Meeting, BNL


Test Setup at CERN-PS

June 2002

STAR PMD Supermodule

Supriya Das : Junior’s Day, STAR Collaboration Meeting, BNL


Supermodule Test Results I

Pulse height spectrum

Variation of Efficiency &

Pulse height with Voltage

# of cells hit = 1.091

Pion beam at 5 GeV/c

Supriya Das : Junior’s Day, STAR Collaboration Meeting, BNL


Preshower spectra

Calibration curve

Supermodule Test Results II

Test with electron beams

Supriya Das : Junior’s Day, STAR Collaboration Meeting, BNL


PMD in Wide Angle Hall

Supriya Das : Junior’s Day, STAR Collaboration Meeting, BNL


The suspension mechanism for PMD

Supriya Das : Junior’s Day, STAR Collaboration Meeting, BNL


PMD Installation

Supriya Das : Junior’s Day, STAR Collaboration Meeting, BNL


DAQ:Number of Chains and C-RAMS

  • One Unit Module (UM) consists of 24x24 = 576 cells

  • One UM has 9 Gas - 4 Boards each with 4 chips

  • (= 64 Multiplexed channels per board)

  • 3 of UM are daisy chained in ONE FEE Chain

    • In ONE Chain: 27 Nos. Gas-4 boards i.e. 27x64 = 1728 channels

  • In total there are 72 UM per plane.

  • Two planes: 72 x 2 = 144 Unit Modules.

    • Total Number of FEE chains 144/3 = 48

  • One C-RAM has 2 Blocks

  • One Block = 2K Channels and Total 4K Channels/C-RAM

  • 1728 channels/Block i.e. ONE chain/Block will be used

    • Total Nos. of C-RAMS required are 24.

Supriya Das : Junior’s Day, STAR Collaboration Meeting, BNL


PMD trigger timing diagram

Supriya Das : Junior’s Day, STAR Collaboration Meeting, BNL


Typical pedestal plot for one FEE chain

Supriya Das : Junior’s Day, STAR Collaboration Meeting, BNL


Network Power Switch

NIM Crate for Trigger Elec.

NIM Crate for CLK,CLR,T/H

VME Crate for DAQ(pmd01)

VME Crate for HV Control

VME Crate for DAQ(pmd02)

Slow Control for PMD at STAR

To Main DAQ Network

Fibre Optic

Ethernet Hub for DAQ Network

To Main Slow Control Network

Ethernet Hub for Slow Control Network

Motor Movement Control(PMD)

CAN BUS

MVME 167B

CAN BUS

PL-500 LV unit

PL-500 LV unit

HV Serial

LeCroy 1454 HV Unit

RACK-1

RACK-2

RACK-3

CAN BUS

CAN BUS

CAN BUS

HV Console

PC-Ethernet

Host PC

PC-CAN-USB

Supriya Das : Junior’s Day, STAR Collaboration Meeting, BNL


Journey so far …

  • Suspension and moving mechanism for PMD has been installed on

  • the east wall of the WAH.

  • The stainless steel support plate and lead converter plates have been

  • installed.

  • All LV, HV and signal cables including various optical cables have

  • been laid.

  • Gas supply and distribution system has been installed.

  • 10 Supermodules have been installed in the last shut down period.

  • 7 FEE chains have been installed and tested.

  • Pedestal taken for all seven FEE chains.

  • Slow control for Cathode High Voltage, FEE Low Voltage and VME

  • crates have been set up and working.

Supriya Das : Junior’s Day, STAR Collaboration Meeting, BNL


PMD with other detectors

PMD

Implementation in GSTAR

Front view of PMD in GSTAR

Supriya Das : Junior’s Day, STAR Collaboration Meeting, BNL


Offline reconstruction framework

Supriya Das : Junior’s Day, STAR Collaboration Meeting, BNL


Summary

  • Photon Multiplicity Detector is a preshower detector which measures

  • the multiplicity and spatial distribution of photons in the forward region

  • of STAR.

  • In combination with the charged particle data from the FTPC, it studies

  • different important physics aspects.

  • A major portion of the detector has already been installed.

  • The DAQ, Trigger and Slow control systems has been set up.

Looking forward for data from d+Au and p+p runs for

detector Calibration and understanding of the different aspects

of the detector.

Getting ready for real physics data from Au+Au run.

Supriya Das : Junior’s Day, STAR Collaboration Meeting, BNL


ad