Hadron Calorimeter decoding schemes


Due to various (historical, convinience, disorder) reasons there are quite a few decoding (numbering) schemes for DELPHI Hadron Calorimeter. This is an attempt to put all eggs in one basket.

All coordinates are given in DELPHI frame reference, i.e. in right ortogonal coordinate system, with X to the center of LEP (from the pit lift), Y - upwards, Z - as electrons direction (from A to C, also as a magnetic field inside the coil). All dimensions are in centimeters.


| Geometry | Offline | High voltage(CAEN) | Cathode |

Geometry Data Base decoding

The data here is from CARGO geometry data base. HAC consists of 4 parts: HAB*, HAF3, HAF4, HAF1, HAF2. The pictures shows modules names from database. HAB HAF-A HAF-C : Not Yet Available In order to investigate HAC geometry database one could use DLIST program (with tree=geom card). To draw detector on various graphic devices use DVP.

Offline decoding

Detector is divided on 4 regions as Endcap A, Barrel A, Barrel C, Endcap C. There are 24 sectors in phi, 4 layers in R(Z in Endcaps) and 96 sectors in theta. Barrel C Endcap C

High voltage(CAEN) decoding

There are 4 CAEN high voltage power supplies in rooms A2, B3(two) and C2. One CAEN channel supplies power to one HAC module(96 in total) with 20(19 in endcap) planes.

Cathode readout(tubes) decoding

Hadron calorimeter barrel module contains 219 streamer tubes. There are 12 readout crates in barrel. Each crate holds 4 64-bit input cards. Thus one crate covers 4 modules. Crates 1-6 are for Barrel A, crates 7-12 for Barrel C. Note that in raw data the crate number starts from 0. The offline(DELANA) coding is module/plane/tube packed number.
1 November 1995 by OS