# Presentation: 601276

## Status of the Phobos 

**Status of the Phobos **
**experiment at RHIC**

**S.Manly**
**Univ. of Rochester**
**(http://maxwell.nsrl.rochester.edu/smanly/)**
***for the***** **
**Phobos Collaboration**
***APS - Atlanta***
***March 23, 1999***

**http://phobos-srv.lns.mit.edu**

## Slide 2

## Phobos Collaboration

**Birger Back, Alan Wuosmaa**
_**BROOKHAVEN NATIONAL LABORATORY**_
**Mark Baker, Donald Barton, Alan Carroll, Stephen Gushue, George Heinzelman, Louis Remsberg, Andrei Sukhanov**
_**CASE-WESTERN RESERVE UNIVERSITY**_**Cyrus Taylor**
_**INSTITUTE OF NUCLEAR PHYSICS, KRAKOW**_**Wojciech Bogucki , Andrzej Budzanowski, Tomir Coghen, Kazimierz Galuszka, Jan Godlewski ,Roman Holynski, **
**Jerzy Kotula, Marian Lemler, Jerzy Michalowski, Andrzej Olszewski, Pawel Sawicki **
**Marek Stodulski, Adam Trzupek, Barbara Wosiek, Krzysztof Wozniak, Pawel Zychowski**
_**JAGELLONIAN UNIVERSITY, KRAKOW**_**Andrzej Bialas, Wieslaw Czyz, Kacper Zalewski**
_**MASSACHUSETTS INSTITUTE OF TECHNOLOGY**_**Wit Busza*, Patrick Decowski, Kristjan Gulbrandsen, P. Haridas, Piotr Kulinich, Heinz Pernegger, Miro Plesko, Gunther Roland†, Leslie Rosenberg, Pradeep Sarin, Stephen Steadman, George Stephans, Gerrit van Nieuwenhuizen, Carla Vale, Robin Verdier, Bernard Wadsworth, Bolek Wyslouch‡**
_**NATIONAL CENTRAL UNIVERSITY, TAIWAN**_**Yuan-Hann Chang, Augustine Chen, Willis Lin**
_**UNIVERSITY OF ROCHESTER**_**Adam Hayes, Erik Johnson, Steven Manly, Robert Pak, Inkyu Park, Frank Wolfs**
_**UNIVERSITY OF ILLINOIS AT CHICAGO**_**Russell Betts, Clive Halliwell, Burt Holzman, Judith Katzy, Wojtek Kucewicz, **
**Don McLeod, Rachid Nouicer, Michael Reuter**
_**UNIVERSITY OF MARYLAND**_**Edmundo Garcia-Solis, Peter Stanskas, Alice Mignerey**

- *Spokesperson†At Goethe University, Frankfurt‡Project Manager

##    4 detector 

**    ****measuring charged particle **
**    ****multiplicity and d  N/d********d******
-    **multiparticle spectrometer**
**      ****covers 1% solid angle **
**      ****at midrapidity with**
**      ****low P****t**** threshold and good**
**      ****particle identification**

- time of flight

- multiplicity
- detectors

- spectrometer

- magnet

**Two detectors:**

- 2

## Primary detector technology

*Silicon detector schema*

- +HV

- p+ Implant

- n+

- Polysilicon
- Drain Resistor

**Dielectric 1**

- bias bus

- signal lines

**Dielectric 2**

- vias

- metal 1

- metal 2

**Primary detector technology**

**Silicon strips and pads**
**300 microns**

## Multiplicity array

- -0.55 m

- -5.04 m

- -2.34 m

- -1.13 m

-  0.55 m

-  1.13 m

-  2.34 m

-  5.04 m

- z

- ****

****

- ****

**  ****85% of 4******** covered**
** ****Charged part. multiplicity d****2****N/d********d******** ****  **(  is azimuthal angle to beam)  ************** and ******
** ****Distinguish multiple hits by the ****   energy deposition**

**Multiplicity array**

## Multiplicity determination (event-by-event)

- 

**Multiplicity determination (event-by-event)**

## The vertex detector

**Beam**

**z**

** ****12.5 cm**

** ****-12.5 cm**

**11 cm**

**5.5 cm**

**x**

**The vertex detector**

- Vertex detector

**Octagon**
**multiplicity **
**detector**

## Two-arm multiparticle Spectrometer

**100 MeV/c**

**1 GeV/c**

- 2 Tesla conventional magnet
- low field region helps with
-     pattern recognition
- Particle ID via dE/dx

## Spectrometer performance

## Slide 11

## Spectrometer physics

**  ****Pt spectra**
**  ****correlations**
**  ****phi mass, width**
**  ****particle ratios**

## Facilities

**Counting house**

**Holes thru berm for cables**

**Cable trays**

## magnet

- Danfysik

- AGS

- RHIC!!

## Phobos Sensor Production

- NCU Taiwan:
- Production &
- Pre-Testing

- MIT and UIC:
- Testing

- Spectrometer

- Vertex and Multiplicity

- DHL

## Silicon detector assembly and testing

**Clean Rooms**

**Probe Stations**

**Inspection stations**

**Hughes 2470-V bonder**

**Gluing Station**

**Si detectors mounted **
**on spectrometer **
**cooling/support frame**

## Trigger Counters

## Time-of-flight system

**Time-of-flight system**

**BC-404 fast plastic from Bicron**

**Hamamatsu R5900-00-M4MOD**
** ****12 stage multi-anode PMTs**

## Si Bias

## MercuryTM RACEwayTM System

*MercuryTM RACEwayTM* System

**A**

**B**

**C**

**D**

***ILK 8 Mercury Backplane ( 8 Slots - only 3 are shown here)***

***Standard VME Backplane***

***To Event Builder******over Ethernet***

***MCH6***

**A**

**B**

**C**

**D**

***MCH6***

**0**

**2**

**1**

***MCH6***

**A**

**B**

**C**

**D**

***PowerPC 750***
***32MB DRAM ***
***1MB SRAM L2 Cache***
***32kB L1 Cache***

- FPDP

## Event Builder

## Test beams

## Slide 23

## Software

**Root/C++**

**Software**

## Miscellaneous 

**One spectrometer arm for **
**year-one running**
**~20 silicon detectors **
**(mostly multiplicity and vertex),**
**DAQ, trigger, and parts of TOF**
**installed for commissioning run**
**this summer**

## conclusions

**PHOBOS is becoming a reality**
**Significant parts of PHOBOS will be installed for**
**	****commissioning run.  **
**Expect to be ready for day-1 physics (except for a**
**	****completed second arm)**