M. De Giorgi

Construction and test of the final CMS Barrel Drift Tube Muon Chamber prototype

A prototype of the CMS Barrel Muon Detector incorporating all the features of the final chambers was built using the mass production assembly procedures and tools. The performance of this prototype was studied in a muon test beam at CERN and the results obtained are presented in this paper.

Performance of the drift tubes for the barrel muon chambers of the CMS detector at LHC

Abstract The barrel muon chambers of the CMS detector consist of three sets of four layers of rectangular drift tubes. The performance of several prototypes was measured in a muon beam for various experimental conditions. Special emphasis was given to study performance aspects related to the trigger capability of the chambers.

A large solid angle magnetic detector for precision studies of e.m. processes in low-energy p interactions

The detector presented is designed to measure the proton e.m. form factors by measuring e+e− pairs produced in pp annihilations at low energy or at rest. In this paper the apparatus is described in detail, with emphasis on how to achieve a suppression factor of about 1010 of the hadronic background.

Study of magnetic field effects in drift tubes for the barrel muon chambers of the CMS detector at the LHC

Abstract The drift chambers in the barrel region of the CMS detector are exposed to magnetic stray fields. To study the performance of the muon reconstruction and the drift time-based muon trigger, prototypes were tested under the expected magnetic field conditions at the H2 test facility at CERN. The results indicate that the overall chamber performance will not be affected. Only the bunch crossing identification capability in the small region near η =1.1, corresponding to the border of the solid angle region covered by the barrel, will be weakened.

Test results of the ASIC front-end trigger prototypes for the muon barrel detector of CMS at LHC

Abstract A sample of ASIC prototypes of the first-level trigger front-end device for the muon barrel drift chambers of CMS was tested on a full size chamber prototype. Tests were performed at several incident angles on cosmic rays and at normal incidence using a muon beam. The chamber was irradiated using a 137 C s gamma source to simulate the LHC radiation environment. The performance of the tested prototypes with respect to efficiency, resolution and noise issues is reported.

Drift time measurements in limited streamer tubes

Abstract We have investigated the performances of drift time techniques applied to limited streamer tubes. A resolution of ∼ 150 μm in the coordinate across the wire is found and a way to solve the left-right ambiguity is presented.

A measurement of the pp→π+π− reaction for 158⩽p(p)⩽275 MeV/c

Abstract A measurement of the total cross section for the reaction p p → π+π− has been performed for seven values of the incident momentum between 158 and 275 MeV/c. The values obtained, if compared with previous results at higher momenta, agree with a 1/s dependence. The differential cross section sssumed over the whole incident momentum range has also been measured and the result of a fit by Legendre polynomials is given.

Resolution of plastic streamer tubes with analog readout

Abstract Extruded plastic tubes coated with a resistive material, having a 1 cm 2 profile and central 100 μm anode wire are operated in limited streamer mode. The charge induced on an external layer of cathode strips aligned perpendicularly to the anode wire is measured and used to compute the streamer coordinate. Test results both with an X-ray source and a particle beam are presented. Spatial resolution of the other of 400 μm is observed over the 40 cm 2 area studied.

Efficiency studies of the front-end trigger device of the muon drift tubes for the CMS detector at LHC

Abstract Three simplified prototypes of the first-level trigger front-end device for the muon barrel drift chambers of CMS were tested on a chamber prototype. Tests were performed at several incidence angles of a muon beam and with different magnetic field configurations. The recorded drift times were also used to test a full software model reproducing the actual algorithm applied in the final ASIC being produced. The efficiency performance of this software model and of the tested prototype are presented in this paper.

Further studies on a DTBX prototype for the CMS muon detector at LHC

Abstract The performance of a small prototype chamber of the baseline project for the muon barrel detector for CMS has been studied in a muon beam. Its efficiency with different gases and wire diameters, the trigger possibilities and the response in presence of a large number of electromagnetic secondaries associated to the muon are evaluated. The results are compared with a full Monte Carlo simulation.