W. Cleland

Radiation qualification of the front-end electronics for the readout of the ATLAS liquid argon calorimeters

The ATLAS detector has been built to study the reactions produced by the Large Hadron Collider (LHC). ATLAS includes a system of liquid argon calorimeters for energy measurements. The electronics for amplifying, shaping, sampling, pipelining, and digitizing the calorimeter signals is implemented on a set of front-end electronic boards. The front-end boards are installed in crates mounted between the calorimeters, where they will be subjected to significant levels of radiation during LHC operation. As a result, all components used on the front-end boards had to be subjected to an extensive set of radiation qualification tests. This paper describes radiation-tolerant designs, radiation testing, and radiation qualification of the front-end readout system for the ATLAS liquid argon calorimeters.

A large liquid argon photon/hadron calorimeter for FNAL

Abstract This paper describes a new liguid argon photon/hadron detector currently under construction for Experiment E706 at the Fermi National Accelerator Laboratory.

A highly segmented NaI(Tl) detector with vacuum photodiode readout for measuring electromagnetic showers at the CERN ISR

Abstract In this report we describe construction and performance of two identical units of electromagnetic shower counters which were installed in the axial-field spectrometer at the CERN-ISR in 1982 to provide improved detection of photons and electrons over a 1.3 sr solid angle of the AFS calorimeter. Thallium doped sodium-iodide in the form of small blocks served as an active shower material. Vacuum photodiodes and low-noise charge sensitive electronics were used for the deposited energy measurement and signal amplification. The stable performance of the detectors over a period of more than 18 months until the closure of the ISR has proven that vacuum photodiodes can reliably be utilized in highly modularized large scale detectors operating in a high magnetic field environment.

A real-time expert system for trigger-logic monitoring

Abstract We are developing a novel real-time expert system to monitor the performance of a triggering system in a high-energy/nuclear physics experiment at Brookhaven National Laboratory (Experiment 814). The system runs on an 80386 processor that is completely independent of the data-acquisition computer for the experiment. Artificial intelligence techniques are seen as especially important for the diagnostic capability of the system. In particular, a separation of the diagnostic knowledge from the control procedures facilitates modification of the expert system and hence the diagnostic capability of the overall system. This is highly desirable as changes in the trigger conditions often occur during the course of a physics run. In addition, one of the objectives of this research is to develop a system which is capable of detecting fault conditions in a serial trigger processor and to aid in locating their cause.