Pad HPD test beam

September 1999

 

This page provides information concerning the beam tests scheduled for the period 7 - 14 July 1999. The tests will be performed in the X7 area of the SPS complex. The plan is to test a Pad HPD with Viking readout in a Cherenkov radiator set-up, where C2F6 or C4F10 gas will be used as light emitting medium.

The set-up consists of a gas radiator volume of 2 m radiator length, equipped with a tilted spherical mirror of 1 m focal length. The HPD is situated in the focus, outside the particle beam.

The beam is defined by 2 scintillator pairs in front of and behind the radiator. In addition 3 silicon pad planes are installed in front of the radiator and one plane behind it. The preliminary configuration of the set-up looks like this...

test_beam_setup.gif (3535 bytes)

A technical drawing of the radiator vessel is shown below...

test_beam_setup_technical.gif (12111 bytes)

The global coordinate system has its origin at the intersection of the beam axis and the mirror.

test_beam_coord.gif (3906 bytes)

The arrangement of the components and concrete blocks is shown below...

test_beam_setup_2.gif (22097 bytes)

Data acquisition

The data acquisition system consists of the following VME modules:

SEQSI: Sequencer, defines hold + clocking signal for Viking chips
C-RAMS: Digitization of sampled Viking signals, pedestal subtraction, zero suppression
RIO: VME based UNIX processor, reads C-RAMS, sends data as binary files to HP workstation for further processing.

Software

Any "online" monitoring is based on the binary files arriving at the HP work station. A first description of the online software can be found here.

The following tools are under development:

TCL/TK based display of HPD
TCL/TK based display of the 4 beam telescopes
Monitoring of efficiencies, rates, occupancies
Reconstruction of tracks and photons, calculation of Cherenkov angles

Other useful  links

X7 test beam page
HPD Si sensor pad map
Beam telescope strip map

Last updated by CJ: 07/06/01