The ALEPH Electromagnetic Calorimeter for LEP

High energy physics

Altoon, Butrus Youkhana

University:University of Glasgow

关键词: High energy physics;   

Others  :  http://theses.gla.ac.uk/77720/1/10998191.pdf

来源: University of Glasgow

【 摘 要 】

This thesis is an account of work carried out at the Physics Department, University of Glasgow in cooperation with Rutherford Appleton Laboratory, Didcot, and CERN, Geneva, between October 1986 and October 1988. The object of the work was to study the uniformity of the ALEPH electromagnetic calorimeter petals, eight of which have been built in the Department. This work deals mainly with the analysis of the anode wire pulsing tests of the modules which were built in this department, and also the analysis of the test beam data taken on the X7b beam in the west area at CERN during the summer of 1987. The results of wire pulsing, cosmic ray tests and test beam running are compatible with the designed response uniformity of 1%. Wire pulsing has proved to be an important tool for the discovery of faults during the construction stage, due to e.g. missing pads, missing towers, broken wires etc. Results from the test beam proved that the calorimeter modules show good linearity and an energy resolution consistent with the design value for the calorimeter. A uniformity of better than 2% has been achieved so far from the cosmic ray and the beam tests. A detailed description of the systems used in these tests is given in chapters 4 and 5. Chapter 1 reviews physics related to e+e- colliders and in particular the LEP collider. The chapter includes a brief description of the LEP experiments and a discussion of some detailed aspects of the physics to be studied at LEP, e.g. e+e- interactions, physics at the Z pole, toponium physics, neutrino counting and Higgs particles. The second chapter reviews the published work related to electromagnetic and hadron calorimeters and their performance. Chapter 3 describes the construction and performance of the ALEPH detector. Some results of tests on the ALEPH components carried out by different groups within the ALEPH collaboration are presented. Chapter 4 deals with the construction of the Electromagnetic Calorimeter (ECAL), in particular with the operations carried out in the department and with the test procedures adopted during construction. The results of the analysis of the module uniformity carried out during the period of this work are presented and discussed in chapter 5. Chapter 6 gives a summary of the tests and conclusions.