P Cabanelas Hades Telescope

Proyecto

2nd Workshop, Compostela, February 2010

The HADES RPC Cosmic Ray Telescope:Preliminary Analysis

Pablo Cabanelas

Laboratorio Carmen Fernández, USC

OUTLINE:

● Overview of the HADES RPC ToF Wall

● The Cosmic Ray Commissioning

● Close to the first TRASGO

● Preliminary Analysis Results

RPC

The HADES RPC ToF Wall

Consist on 1122 shielded 4-gap timing RPC cells (0.280mm/gap), covering about 8m2, distributed like this:

● 6 almost-identical sectors

● 2 RPC layers per sector

● 3 columns of RPC cells per layer

● 31 RPC cells per column

The RPC Commissioning

From April 2009 to nowadays

1. The 6 sectors were instrumented by pairs at the

GSI and placed at horizontal position.

2. Cosmic Ray test was performed with such a

setup.

3. At the end, they were mounted on their nominal

position in HADES.

4. Currently, they are just there, a bit bored,

waiting for a beam to take data.

Hit distribution of cosmic rays over the 6 RPC sectors

Cosmic ray commissioning summary:

● 6 RPC sectors fully instrumented, tested,

validated and mounted in HADES

● About 50 days of data taken at a rate of 200

Hz over a pair of sectors

● 895 Gb of data stored

● 1122 RPC cells operative as well as 2243

channels (all but one!)

A Tracking Algorithm forTRASGOS

timtrack

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Proyecto

Already introducedTo be presented by

J.Garzón

Preliminary Cosmic Ray Analysis with TimTrack

T0

Vz

y

xL

z=0

Y0

X0

X’

Y’

z

V

TimTrack:

33cm

Preliminary Cosmic Ray Analysis with TimTrack

Analyzed events crossing one set of four RPC cells

~42cm~5cm

Ref Plane

ZX

Preliminary Cosmic Ray Analysis with TimTrack

Some Ultra-Preliminary Results!!!

Reconstructed X at the reference plane

Reconstructed X vs X' (slope): acceptance

Preliminary Cosmic Ray Analysis with TimTrack

Some Ultra-Preliminary Results!!!

Reconstructed T0 (Time at the reference

plane) in ps [Not calibrated]

Two-Peak structure

~6-8 ns

Close to the first TRASGO ??

TRASGO:

Several planes (4 at least) of ?-gap RPC strips

2 HADES RPC sectors:

Four planes of shielded 4-gap RPCs

Different Geometry -- Same FEE, DAQ and Analysis