A purity monitoring system for the H1 Liquid Argon Calorimeter 15mn

A. Babaev (Moscow)

The ionization probes used for monitoring of the liquid argonpurity in H1 calorimeter are described and results of their operation in tests at CERN and during the period 1992 to the end of 1998 at HERA collider are given. The sensitivity of our charge measurement at the level of 0.03 % leads us to refine charge collection models and to discover a variation of the response of our beta probes with temperature.

Performances of the NA48 pipelined trigger for the Kaon neutral decays15mn

S. Giudici Pisa (Italy)

The NA48 collaboration has recently presented the measurement of the direct CP violation parameter Re(e'/e) = 14.0 +- 4.3 combining the data collected in the year 1997 and 1998. The final goal of the experiment is to reduce the error at the level of 2*10^-4. The electro magnetic calorimeter based on liquid Krypton, used in the experiment, plays a crucial role to achieve such an accuracy. The trigger input for the selection of K0 -> 2pi0 decays consists of a 40 MHz "dead-time free" pipelined system and is based on about 13500 cells in which the calorimeter is segmented. Every 25 ns the total energy released in the calorimeter, its first and second moment, the number of showers and their accurate timing at 3 ns in X and Y calorimeter projections are computed. Using these quantities the kaon lifetime is also computed at each clock cycle. Performances of the trigger system are discussed.

Performances of the NA48 Liquid Krypton calorimeter 30mn

G. Unal (Orsay)

The NA48 experiment aims at measuring direct CP violation in the Kaon system through the double ratio of the decay rates of Kl and Ks to neutral and charged pions. To reach the desired accuracy of ~ 0.1% on the double ratio, the calorimeter used to detect photons should have a good energy and time resolutions, stability, uniformity and a small non linearity. The calorimeter used by NA48 is a quasi homogeneous liquid Krypton calorimeter, with fast read out. The performances of this device, measured using data taken during the period 1997-1999, will be discussed, with a special emphasis on the intercalibration, energy resolution and on the studies of systematic effects like the non linearity.

D0 Calorimeter Upgrades for Tevatron Run IIL 25 mn.

Groer (Fnal)

The complete electronic readout system for the D0 liquid argon calorimeter has been replaced to take advantage of the upcoming Tevatron Run II. Scintillation detectors in the intercryostat regions have been replaced as well. I will discuss these up

The ATLAS liquid argon couleur calorimetry 15 mn

A. Kiryunin (CPPM)

The Atlas collaboration has chosen an accordion shape liquid argon/lead technique for its electromagnetic calorimetry. Also a hadronic endcap and a forward calorimeters will be located in the same cryostats. This ensemble of detectors will be described. Results from beam tests of pre-production and production modules will be introduced. A status of the production will be presented.

Performance of the ATLAS electromagnetic calorimeter: tests of barrel and end cap modules 20 mn

C. Clement (Stockolm)

The ATLAS experiment at CERN's LHC collider will use a novel type of electromagnetic calorimeter, based on a design using accordion shaped electrodes and absorbers. The geometry allows to achieve a complete azimuthal coverage without any gaps due to cables or supporting structures. Here are presented results of tests performed on the first barrel and endcap calorimeter modules with the final ATLAS design. These results include noise and cross-talk studies, response to minimum ionising particles, energy resolution for electrons, linearity and uniformity studies, effect of upstream material.

Test-Beam Results for First Serial Module of ATLAS Hadronic End-Cap Calorimeter 15mn

A. Minaenko (IFVE)

Beam tests of the first serial modules of the ATLAS liquid argon Hadronic End-cap Calorimeter were carried out during 2000. Analysis of the data obtained with electron, pion and muon beams are presented in this report. The linearity and spatial uniformity of the response are tested using both electron and pion data. The energy dependence of the energy resolution for both electron and pion beams is measured and fitted to extract sampling and constant terms. The results are compared with GEANT3/GCALOR simulations.

Test Beam Measurements of the Response Hadrons of the ATLAS Forward Calorimeter 15mn

D. Bailey (toronto)

Due to the severe radiation environment, the ATLAS detector will incorporate a compact liquid argon forward calorimeter. The electrode design is unique and consists of hexagonally packed, tubular, thin gap electrodes running parallel to the beam. The device is longitudinally divided into three modules; the module closest to the interaction point comprises copper absorber and electrodes, and the two longitudinally following modules are of tungsten. We report the results of test beam studies of the response of the device to hadrons in the energy range 20 GeV to 200 GeV. The measured energy resolution meets the ATLAS design requirements.