ABSTRACT
The Compact Muon Solenoid (CMS) is a particle physics experiment situated on the Large Hadron Collider (LHC) at CERN, Switzerland. The CMS upgrade (planned for 2025) involves installing a new advanced sensor system within the CMS tracker, the centre of the detector closest to the particle collisions. The increased heat load associated with these sensors has required the design of an enhanced cooling system that exploits the latent heat of 40 bar CO2. In order to minimise interaction with the incident radiation and improve the detector performance, the cooling pipes within this system need to be thin-walled (~100 µm) and strong enough to withstand these pressures. The purpose of this paper is to analyse the microstructure and mechanical properties of thin-walled cooling pipes currently in use in existing detectors to assess their potential for the tracker upgrade. In total, 22 different pipes were examined, which were composed of CuNi, SS316L, and Ti and were coated with Ni, Cu, and Au. The samples were characterised using computer tomography for 3D structural assessment, focused ion beam ring-core milling for microscale residual stress analysis, optical profilometry for surface roughness, optical microscopy for grain size analysis, and energy dispersive X-ray spectroscopy for elemental analysis. Overall, this examination demonstrated that the Ni- and Cu-coated SS316L tubing was optimal due to a combination of low residual stress (20 MPa axial and 5 MPa hoop absolute), low coating roughness (0.4 µm Ra), minimal elemental diffusion, and a small void fraction (1.4%). This result offers a crucial starting point for the ongoing thin-walled pipe selection, development, and pipe-joining research required for the CMS tracker upgrade, as well as the widespread use of CO2 cooling systems in general.
ABSTRACT
PURPOSE: The aim of the following paper was Polish cultural and linguistic adaptation including adaptation of particular questions, instructions and possible answers to 2000 IKDC knee form and Lysholm's scale. MATERIAL/METHODS: The cultural adaptation process of this questionnaire was made according to indicators of International Quality of Life Assessment (IQOLA) project, placed in Journal of Clinical Epidemiology. Testing version (pre-final test) was carried out on 30 patients suffering from instability of a knee. Patients underwent arthroscopic reconstruction of the anterior cruciate ligament. The period from operation to filling in the questionnaires took 2 years. The questionnaire was filled up twice, at intervals from 2 days to 2 weeks. RESULTS: We received cultural and linguistic adapted knee evaluation scales which are similar to the original version according to the psychometric proprieties such as accuracy of a single question and whole scales. CONCLUSIONS: We were able to develop a reliable, ISAKOS/ESSKA-compliant instrument for subjective knee function evaluation to be used in the population of Polish patients following arthroscopic reconstruction of anterior cruciate ligament. Polish version of IKDC 2000 questionnaire is more reliable--i.e. more useful in clinical evaluation of patients with ACL damage--than the Polish rendition of Lysholm scale.
