To the positive miscut influence on the crystal collimation efficiency

The paper concerns the crystal based collimation suggested to upgrade the Large Hadron Collider collimation system. The issue of collimation efficiency dependence on the muscut angle characterizing nonparallelity of the channeling planes and crystal surface is mainly addressed. It is shown for the first time that even the preferable positive miscut could severely deteriorate the channeling collimation efficiency in the crystal collimation UA9 experiment. We demonstrate that the positive miscut influence can increase the nuclear reaction rate in the perfectly aligned crystal collimator by a factor of 4.5. We also discuss the possible miscut influence on the future LHC crystal collimation system performance as well as suggest simple estimates for the beam diffusion step, average impact parameter of particle collisions with the collimator and angular divergence of the colliding particle beam portion.Comment: 14 pages, 9 figure

CRYSTAL Simulation Code and New Coherent Effects in Bent Crystal at the LHC

The LHC crystal-based collimation system is mainly addressed. A CRYSTAL simulation code for particle tracking in crystals is introduced. Its essence consists in both adequate and fast sampling of proton trajectories in crystals which is crucial for both correct description of experiments and quantitative prediction of new effects. The H8 single-pass experiment at the CERN SPS as well as 7 TeV proton deflection by a bent crystal at the LHC are simulated. We predict the existence of dechanneling peaks corresponding to the planar channeling oscillations as well as describe the possibility of their observation at high energies, specifically in the LHC crystal-assisted collimation experiment planned on 2015. An effect of excess over the amorphous level of ionization losses in the channeling mode was also found for the LHC energy. In addition, the LHC crystal-based collimation system is simulated as well as its possible improved layouts with application of a crystal with the cut and multiple volume reflection in one bent crystal.Comment: The results of this paper were presented on the 6th International Conference "Charged & Neutral Particles Channeling Phenomena - Channeling 2014" organized by the Italian National Institute for Nuclear Physics (INFN) and the European Organization for Nuclear Research (CERN) held in Capri (Capri-Naples, Italy) on October 5-10, 201

Multiple Volume Reflection from Different Planes Inside One Bent Crystal

It is shown that multiple volume reflections from different planes of one bent crystal becomes possible when particles move at a small angle with respect to a crystal axis. Such a Multiple Volume Reflection makes it possible to increase the particle deflection angle inside one crystal by more than four times and can be used to increase the efficiency of beam extraction and collimation at the LHC and many other accelerators.Comment: 17 pages, 6 figure

Autonomous and Environmentally Comfortable Type of Housing for the Development of the Arctic

Factors that impede the development of the Arctic are: 1) long frosts; 2) low quality of indoor air; 3) an unsanitary surroundings due to low activity of biota; 4) deficiency of fresh vitamin-containing food; 5) high dependency of settlements on external supply. The concept of the Arctic Ecological- Energy Autonomous Dwelling (AEEAD) designed to solve the problems is grounded on: 1) the optimal configuration of housing and heat savings; 2) closure of the flows of substances; 3) the use of autonomous energy sources. To ensure energy savings and maintain a high quality of life air revitalization is required. Air revitalization is provided by household greenhouses, which perform additional functions – heating the living quarters, lighting it, moistening the winter overdried air, growing food, decorating house interior, providing psychological support. New technologies for growing a variety of plants and organic wastes decomposition are discussed. Energetic autonomy is provided by means coupling wind generator with high-heat accumulators based on cheap solid heat-storage materials coupled, in its turn, with Stirling engine/electrical generator unit. Due to “macro-composite” structure of heat exchanger it can be achieved: almost zero heat loss in the absence of thermal insulation; a significant stabilization of the temperature at the output of the thermal battery, over the whole period of the discharg

Geant4 simulation model of electromagnetic processes in oriented crystals for the accelerator physics

Electromagnetic processes of charged particles interaction with oriented crystals provide a wide variety of innovative applications such as beam steering, crystal-based extraction/collimation of leptons and hadrons in an accelerator, a fixed-target experiment on magnetic and electric dipole moment measurement, X-ray and gamma radiation source for radiotherapy and nuclear physics and a positron source for lepton and muon colliders, a compact crystalline calorimeter as well as plasma acceleration in the crystal media. One of the main challenges is to develop an up-to-date, universal and fast simulation tool to simulate these applications. We present a new simulation model of electromagnetic processes in oriented crystals implemented into Geant4, which is a toolkit for the simulation of the passage of particles through matter. We validate the model with the experimental data as well as discuss the advantages and perspectives of this model for the applications of oriented crystals mentioned above.Comment: 18 pages, 9 figure

Genome-wide association study of Tourette Syndrome

Tourette Syndrome (TS) is a developmental disorder that has one of the highest familial recurrence rates among neuropsychiatric diseases with complex inheritance. However, the identification of definitive TS susceptibility genes remains elusive. Here, we report the first genome-wide association study (GWAS) of TS in 1285 cases and 4964 ancestry-matched controls of European ancestry, including two European-derived population isolates, Ashkenazi Jews from North America and Israel, and French Canadians from Quebec, Canada. In a primary meta-analysis of GWAS data from these European ancestry samples, no markers achieved a genome-wide threshold of significance (p<5 × 10−8); the top signal was found in rs7868992 on chromosome 9q32 within COL27A1 (p=1.85 × 10−6). A secondary analysis including an additional 211 cases and 285 controls from two closely-related Latin-American population isolates from the Central Valley of Costa Rica and Antioquia, Colombia also identified rs7868992 as the top signal (p=3.6 × 10−7 for the combined sample of 1496 cases and 5249 controls following imputation with 1000 Genomes data). This study lays the groundwork for the eventual identification of common TS susceptibility variants in larger cohorts and helps to provide a more complete understanding of the full genetic architecture of this disorder

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements