Flux Loop Measurements of the Magnetic Flux Density in the CMS Magnet Yoke

The Compact Muon Solenoid (CMS) is a general purpose detector, designed to run at the highest luminosity at the CERN Large Hadron Collider (LHC). Its distinctive features include a 4 T superconducting solenoid with 6-m-diameter by 12.5-m-length free bore, enclosed inside a 10,000-ton return yoke made of construction steel. The return yoke consists of five dodecagonal three-layered barrel wheels and four end-cap disks at each end comprised of steel blocks up to 620 mm thick, which serve as the absorber plates of the muon detection system. To measure the field in and around the steel, a system of 22 flux loops and 82 3-D Hall sensors is installed on the return yoke blocks. A TOSCA 3-D model of the CMS magnet is developed to describe the magnetic field everywhere outside the tracking volume measured with the field-mapping machine. The first attempt is made to measure the magnetic flux density in the steel blocks of the CMS magnet yoke using the standard magnet discharge with the current ramp down speed of 1.5 A/s.Comment: 7 pages, 5 figures, presented at ISCM2016 - 5th International Conference on Superconductivity and Magnetism on April 28, 2016 at Fethiye, Turke

Detrital zircon SHRIMP U-Pb age study of the Cordillera Darwin Metamorphic Complex of Tierra del Fuego : sedimentary sources and implications for the evolution of the Pacific margin of Gondwana

The Cordillera Darwin Metamorphic Complex in the southernmost Andes includes a basement of probable Palaeozoic age, a mid-Jurassic and younger volcano-sedimentary cover, and a suite of Jurassic granites, all of which were jointly metamorphosed during the Cretaceous. Detrital zircon ages presented here show that some of the amphibolite-facies metamorphic rocks previously mapped as basement have a Jurassic protolith. Overall the detrital zircon age patterns for samples of the Cordillera Darwin basement differ from those of the Madre de Dios Terrane of the western Patagonian Andes with which they had been correlated; instead, they are more comparable with those from the Eastern Andes Metamorphic Complex, which apparently developed in a passive margin setting. The paucity of Cambrian detrital zircons indicates that the meta-igneous basement of the Magallanes foreland basin of central and northern Tierra del Fuego was not the main source of detritus for the protolith of the Cordillera Darwin Metamorphic Complex. The possibility is envisaged that the Magallanes Fagnano transform fault boundary between the Scotia and South America plates resulted from reactivation of an older, pre-Jurassic suture zone between the basement terranes of north–central Tierra del Fuego and Cordillera Darwin

Measuring the Magnetic Flux Density with Flux Loops and Hall Probes in the CMS Magnet Flux Return Yoke

The Compact Muon Solenoid (CMS) is a general purpose detector, designed to run at the highest luminosity at the CERN Large Hadron Collider (LHC). Its distinctive features include a 4 T superconducting solenoid with 6-m-diameter by 12.5-m-length free bore, enclosed inside a 10,000-ton return yoke made of construction steel. The flux return yoke consists of five dodecagonal three-layered barrel wheels and four end-cap disks at each end comprised of steel blocks up to 620 mm thick, which serve as the absorber plates of the muon detection system. To measure the field in and around the steel, a system of 22 flux loops and 82 3-D Hall sensors is installed on the return yoke blocks. A TOSCA 3-D model of the CMS magnet is developed to describe the magnetic field everywhere outside the tracking volume that was measured with the field-mapping machine. The voltages induced in the flux loops by the magnetic flux changing during the CMS magnet standard ramps down are measured with six 16-bit DAQ modules. The off-line integration of the induced voltages reconstructs the magnetic flux density in the yoke steel blocks at the operational magnet current of 18.164 kA. The results of the flux loop measurements during three magnet ramps down are presented and discussed.Comment: 3 pages, 6 figures, presented at the IEEE Nuclear Science Symposium 2016 (NSS) in Strasbourg, France on November 3, 2016. arXiv admin note: text overlap with arXiv:1605.0877

Validation of the CMS Magnetic Field Map

The Compact Muon Solenoid (CMS) is a general purpose detector, designed to run at the highest luminosity at the CERN Large Hadron Collider (LHC). Its distinctive features include a 4 T superconducting solenoid with 6-m-diameter by 12.5-m-length free bore, enclosed inside a 10,000-ton return yoke made of construction steel. The return yoke consists of five dodecagonal three-layered barrel wheels and four end-cap disks at each end comprised of steel blocks up to 620 mm thick, which serve as the absorber plates of the muon detection system. To measure the field in and around the steel, a system of 22 flux loops and 82 3-D Hall sensors is installed on the return yoke blocks. A TOSCA 3-D model of the CMS magnet is developed to describe the magnetic field everywhere outside the tracking volume measured with the field-mapping machine. The magnetic field description is compared with the measurements and discussed.Comment: 7 pages, 5 figures, presented at 4th International Conference on Superconductivity and Magnetism 2014, April 27 - May 2, 2014, Antalya, Turkey. arXiv admin note: substantial text overlap with arXiv:1605.08778; text overlap with arXiv:1212.165

Measuring the Magnetic Flux Density in the CMS Steel Yoke

The Compact Muon Solenoid (CMS) is a general purpose detector, designed to run at the highest luminosity at the CERN Large Hadron Collider (LHC). Its distinctive features include a 4 T superconducting solenoid with 6-m-diameter by 12.5-m-length free bore, enclosed inside a 10000-ton return yoke made of construction steel. The return yoke consists of five dodecagonal three-layered barrel wheels and four end-cap disks at each end comprised of steel blocks up to 620 mm thick, which serve as the absorber plates of the muon detection system. Accurate characterization of the magnetic field everywhere in the CMS detector is required. To measure the field in and around the steel, a system of 22 flux-loops and 82 3-D Hall sensors is installed on the return yoke blocks. Fast discharges of the solenoid (190 s time-constant) made during the CMS magnet surface commissioning test at the solenoid central fields of 2.64, 3.16, 3.68 and 4.01 T were used to induce voltages in the flux-loops. The voltages are measured on-line and integrated off-line to obtain the magnetic flux in the steel yoke close to the muon chambers at full excitations of the solenoid. The 3-D Hall sensors installed on the steel-air interfaces give supplementary information on the components of magnetic field and permit to estimate the remanent field in steel to be added to the magnetic flux density obtained by the voltages integration. A TOSCA 3-D model of the CMS magnet is developed to describe the magnetic field everywhere outside the tracking volume measured with the field-mapping machine. The results of the measurements and calculations are presented, compared and discussed.Comment: 9 pages, 7 figures, 16 references, presented at the III International Conference on Superconductivity and Magnetism (ICSM-2012), Kumburgaz, Istanbul, Turkey, 29 April - 4 May 201

On the recurrence set of planar Markov Random Walks

In this paper, we investigate the properties of recurrent planar Markov random walks. More precisely, we study the set of recurrent points with the use of local limit theorems. The Nagaev-Guivarc'h spectral method provides several examples for which these local limit theorems are satisfied as soon as the (standard or non-standard) central limit theorem holds

Molecular gastronomy : basis for a new culinary movement or modern day alchemy?

To explore the phenomenon of molecular gastronomy by conducting empirical research focusing on renowned chefs. Design/methodology/approach - Literature review summarising past culinary innovations then focusing on the origins and evolution of molecular gastronomy, followed by 18 phenomenological interviews with a snowball sample of world class chefs from across Europe. There is far greater confusion about what molecular gastronomy might be than is implied in previous studies. The term has become wrongly used to describe a possible culinary movement mainly as a result of media influence. Leading chefs, whose new restaurant concepts have become associated with it, reject the term. With only 20 years of history molecular gastronomy is still a comparatively new phenomenon, this initial research presents a clear picture of its evolution so far and the increasing confusion the use of the term has created. It's still far too early to decide if these are heralding a new gastronomic movement. Although molecular gastronomy itself may not provide a foundation for a genuine and lasting development of cuisine it is generating fascination with the fundamental science and techniques of cuisine and showy culinary alchemy. As with Nouvelle Cuisine poor quality copycat chefs could bring into disrepute the reputation and practices of those who are at the vanguard culinary and restaurant innovation. Originality/value - First widespread primary study, across five countries, into recognised exceptional chefs' understanding of molecular gastronomy. It clarifies that molecular gastronomy was never intended to be the foundation of a culinary movement and identifies four key elements for the development of lasting cuisine movements and trends

GEN-O-MA project: an Italian network studying clinical course and pathogenic pathways of moyamoya disease—study protocol and preliminary results

Background: GENetics of mOyaMoyA (GEN-O-MA) project is a multicenter observational study implemented in Italy aimed at creating a network of centers involved in moyamoya angiopathy (MA) care and research and at collecting a large series and bio-repository of MA patients, finally aimed at describing the disease phenotype and clinical course as well as at identifying biological or cellular markers for disease progression. The present paper resumes the most important study methodological issues and preliminary results. Methods: Nineteen centers are participating to the study. Patients with both bilateral and unilateral radiologically defined MA are included in the study. For each patient, detailed demographic and clinical as well as neuroimaging data are being collected. When available, biological samples (blood, DNA, CSF, middle cerebral artery samples) are being also collected for biological and cellular studies. Results: Ninety-eight patients (age of onset mean ± SD 35.5 ± 19.6 years; 68.4% females) have been collected so far. 65.3% of patients presented ischemic (50%) and haemorrhagic (15.3%) stroke. A higher female predominance concomitantly with a similar age of onset and clinical features to what was reported in previous studies on Western patients has been confirmed. Conclusion: An accurate and detailed clinical and neuroimaging classification represents the best strategy to provide the characterization of the disease phenotype and clinical course. The collection of a large number of biological samples will permit the identification of biological markers and genetic factors associated with the disease susceptibility in Italy

On fixed points of self maps of the free ball

In this paper, we study the structure of the fixed point sets of noncommutative self maps of the free ball. We show that for such a map that fixes the origin the fixed point set on every level is the intersection of the ball with a linear subspace. We provide an application for the completely isometric isomorphism problem of multiplier algebras of noncommutative complete Pick spaces