121630600
THE CMS TRACKER ALIGNMENT SYSTEM
18347743
Building CMS pixel barrel detector modules
For the barrel part of the CMS pixel tracker about 800 silicon pixel detector modules are required. The modules are bump bonded, assembled and tested at the Paul Scherrer Institute. This article describes the experience acquired during the assembly of the first ∼200 modules.
118773183
Hybridization issues for future applications
119151118
Mechanical design and material budget of the CMS barrel pixel detector
The Compact Muon Solenoid experiment at the Large Hadron Collider at CERN includes a silicon pixel detector as its innermost component. Its main task is the precise reconstruction of charged particles close to the primary interaction vertex. This paper gives an overview of the mechanical requirements and design choices for the barrel pixel detector. The distribution of material in the detector as well as its description in the Monte Carlo simulation are discussed in detail.
109648920
Assembly of the CMS pixel barrel modules
For the barrel part of the CMS pixel tracker about 800 silicon pixel detector modules are required. The modules are bump bonded, assembled and tested at the Paul Scherrer Institute. This article describes the assembly procedure that will be used to build these modules.
109400943
Upgrade plans for the CMS pixel barrel detector
Abstract The pixel detector of the CMS experiment will need to be replaced after a couple of years of LHC running because of radiation damage. On the other hand, plans for a step wise luminosity upgrade of the accelerator beyond the present design value around 2014 are being prepared. While the replacement pixel detector must be designed to handle increased particle rates, it should maintain or improve the tracking performance of the present system and must be compatible with existing services.
120020642
The Low-Energy p–d System in Pionless EFT
We summarize results presented at the 5th Asian Pacific Conference on Few Body Problems in Physics, which was held in Seoul in August 2011. We calculate low-energy quartet and doublet channel proton–deuteron scattering in the framework of pionless effective field theory. We obtain good agreement with the available phase shift analyses. Moreover, we calculate the Coulomb contribution to the 3He–3H binding energy difference in first order perturbation theory.
119918189
Development of a gas filter against wire chamber ageing for the MDT chambers in ATLAS
Drift chamber ageing is a serious concern for the operation of the Monitored Drift Tube chambers (MDT) in the ATLAS muon system. Therefore systematic studies of ageing effects have been carried out at the University of Freiburg. It has been shown that tiny contaminations with volatile silicon compounds, which are found in many components supplied by industry, cause a severe degradation of the drift tube performance. Since the ATLAS MDT system contains many thousands of commercial components the cleanliness of all parts cannot be guaranteed. Therefore gas filters with zeolites have been developed in Freiburg, which remove these impurities efficiently. They will be employed in the gas system for the MDT chambers.
120184923
Recent and ongoing ageing studies for the Atlas muon spectrometer drift tubes
Abstract The Atlas muon spectrometer relies on Monitored Drift Tubes (MDTs) for track reconstruction in most regions. Expected count rates due to photons reach up to 1500 Hz/cm for the innermost MDTs. For a gas gain of 2 × 10 4 , this corresponds to an overall accumulated charge of up to 0.6 C/cm, which the MDTs must be able to withstand in 10 years of LHC operation without a degradation in their performance. With the main MDT parameters and the design frozen and chamber production well under way, the focus of present ageing studies is on testing final Atlas chambers instead of using small, dedicated setups under very well-controlled conditions as in the past. This paper summarizes the results of such a study performed at the CERN Gamma Irradiation Facility GIF under realistic Atlas conditions. One of the main goals was to evaluate for the first time the principle of gas recirculation and a prototype of the Atlas circulation system. The paper also reviews ongoing measurements at CERN and in Freiburg.