We review the physics potential of a next generation search for solar axions: the International Axion Observatory (IAXO) . Endowed with a sensitivity to discover axion-like particles (ALPs) with a ...coupling to photons as small as gaγ∼10−12 GeV−1, or to electrons gae∼10−13, IAXO has the potential to find the QCD axion in the 1 meV∼1 eV mass range where it solves the strong CP problem, can account for the cold dark matter of the Universe and be responsible for the anomalous cooling observed in a number of stellar systems. At the same time, IAXO will have enough sensitivity to detect lower mass axions invoked to explain: 1) the origin of the anomalous “transparency” of the Universe to gamma-rays, 2) the observed soft X-ray excess from galaxy clusters or 3) some inflationary models. In addition, we review string theory axions with parameters accessible by IAXO and discuss their potential role in cosmology as Dark Matter and Dark Radiation as well as their connections to the above mentioned conundrums.
The International Axion Observatory (IAXO) will be a forth generation axion helioscope. As its primary physics goal, IAXO will look for axions or axion-like particles (ALPs) originating in the Sun ...via the Primakoff conversion of the solar plasma photons. In terms of signal-to-noise ratio, IAXO will be about 4-5 orders of magnitude more sensitive than CAST, currently the most powerful axion helioscope, reaching sensitivity to axion-photon couplings down to a few x10 super(-12) GeV super(-1) and thus probing a large fraction of the currently unexplored axion and ALP parameter space. IAXO will also be sensitive to solar axions produced by mechanisms mediated by the axion-electron coupling g sub(ae) with sensitivity - for the first time - to values of g sub(ae) not previously excluded by astrophysics. With several other possible physics cases, IAXO has the potential to serve as a multi-purpose facility for generic axion and ALP research in the next decade. In this paper we present the conceptual design of IAXO, which follows the layout of an enhanced axion helioscope, based on a purpose-built 20 m-long 8-coils toroidal superconducting magnet. All the eight 60cm-diameter magnet bores are equipped with focusing x-ray optics, able to focus the signal photons into ~ 0.2 cm super(2) spots that are imaged by ultra-low-background Micromegas x-ray detectors. The magnet is built into a structure with elevation and azimuth drives that will allow for solar tracking for ~12 h each day.
Information from 2013-2015 have been analysed on water accessibility, types of water service to households, use of water pretreatment, availability of sewerage, use of sewage treatment in Chukotka ...Autonomous Okrug and Yakutia Republic, based on evaluation information accessible in open sources, such as regional statistics and sanitary-epidemiologic reports. The main causes of the poor state of water supply and sanitation in the study regions include: very limited access to in-home running water (one-quarter of settlements in Chukotka and half of settlements in Yakutia have no regular water supply) and lack of centralised sewerage (78% and 94% of settlements correspondingly have no sewerage); lack of water pretreatment and sewage treatment, outdated technologies and systems; serious deterioration of facilities and networks, frequent accidents; secondary pollution of drinking water. Lack of open objective information on Russian Arctic water supply and sanitation in the materials of the regional and federal statistics hampers the assessment of the real state of affairs. The situation for water and sanitation supply in these Russian Arctic regions remains steadily unfavourable. A comprehensive intervention from national and regional governmental levels is urgently needed.
As part of the European Strategy for Particle Physics there is an ongoing development towards a Future Circular Collider (FCC-ee) where electron-positron collisions could be used to study the entire ...electro-weak sector in a low background environment. Particle detectors are used to study these collisions and a strong magnetic field is required to measure the particles' momenta. Currently, two detector concepts are being studied: the Innovative Detector for Electron-positron Accelerators (IDEA) and the CLIC-Like Detector (CLD). Both these detectors include a superconducting solenoid magnet with a central field of <inline-formula><tex-math notation="LaTeX">2 \,\mathrm{T}</tex-math></inline-formula> of which the designs are presented here. The IDEA magnet has an stored magnetic energy density of 14 kJ/kg and in CLD this is 12 kJ/kg. Taking into account their respective free-bore diameters of <inline-formula><tex-math notation="LaTeX">4.2 \,\mathrm{m}</tex-math></inline-formula> for IDEA and <inline-formula><tex-math notation="LaTeX">7.2 \,\mathrm{m}</tex-math></inline-formula> for CLD this results in very challenging designs for which the mechanical and quench studies are presented. Their results are promising, but extensive R&D on these magnets would be needed in the future to reach the goals set out in the Conceptual Design Report (CDR).
The precise measurement of forces is one way to obtain deep insight into the fundamental interactions present in nature. In the context of neutral antimatter, the gravitational interaction is of high ...interest, potentially revealing new forces that violate the weak equivalence principle. Here we report on a successful extension of a tool from atom optics--the moiré deflectometer--for a measurement of the acceleration of slow antiprotons. The setup consists of two identical transmission gratings and a spatially resolving emulsion detector for antiproton annihilations. Absolute referencing of the observed antimatter pattern with a photon pattern experiencing no deflection allows the direct inference of forces present. The concept is also straightforwardly applicable to antihydrogen measurements as pursued by the AEgIS collaboration. The combination of these very different techniques from high energy and atomic physics opens a very promising route to the direct detection of the gravitational acceleration of neutral antimatter.
Particle physics experiments make use of magnetic fields up to <inline-formula><tex-math notation="LaTeX">4 \,\mathrm{T}</tex-math></inline-formula> to bend electrically charged particles such that ...their charge and momentum can be determined. The particle energy measurement requires a low amount of material, or material that is highly transparent to particles inside the calorimeter volume. The conflict between the small volume of space reserved for a magnet and having a field of several teslas inside the detector is often resolved by using superconducting magnets. Up to now, large particle physics detector magnets have been constructed with low temperature superconductors, but there are clear benefits from using high temperature superconductors in future particle physics detector designs, such as allowing for an elevated operating temperature and the reduced amount of superconductor needed. In addition to the HTS material itself, additional material is needed to support the Lorentz forces, and to temporarily carry the current in case of a quench since these magnets are always one-of-a-kind and they need to operate reliably and without damage in case of a failure scenario. The stabilizer has to be a low-density material for high particle transparency, such as aluminium. Since the density of the superconductor is a factor of 4 higher than the density of aluminium, a reduction of superconducting material also means an improvement of the particle transparency: the density of a material is directly related to its particle transparency. This paper presents a conceptual design for high temperature superconducting detector magnets and a study of the type of aluminium stabilizer used.
The international particle physics community considers a Muon Collider (MC) as a possible option for the successor of the Large Hadron Collider (LHC) at CERN. An international collaboration has ...recently been set up to produce a conceptual design study of a Muon Collider. One of the main challenges is the need for an ultra-high magnetic field solenoid for the final cooling of the muons. This magnet must have a bore aperture of about 5 cm and a 1% magnetic field homogeneity over 0.5 m of length. CERN is exploring the possibility of developing such a magnet by only using a stack of Rare-earth Barium Copper Oxide (ReBCO) tapes as a conductor. The study's main idea is to produce a modular compact magnet constituted by an assembly of identical pancakes electrically connected in series. Quench protection and stress management are the biggest design challenges. To cope with them, we are investigating the option of Non/Metal-Insulated (N/M-I) pancakes, each made of a single coil (i.e., discarding concentric, nested coils), inserted in a stiff outer ring that provides a sufficient precompression to the coil (∼200 MPa). To protect the magnet after a quench and to ramp up the field sufficiently fast, the N/M-I coil interlayer electrical resistance must be optimized and controlled. In this paper, we present a preliminary design of this concept. If successful, this type of design will contribute to developing high-field solenoids for particle accelerators and promote the use of ReBCO tapes in compact windings needed for different applications, such as electrical machines and fusion reactors based on magnetic confinement.
Two robot systems for the shaping and machining of polymer-composite products are described. In the shaping system, an industrial robot lays out the fibers as prepreg tape. In the machining system, ...the boring and milling of polymer composites is improved. This system is adapted for the machining of sound-absorbing structures in airplane engines,
In the context of EP R&D, CERN is working on conceptual designs for a possible multi-purpose superconducting magnet test beam facility to be used for future detector and electronic device testing. ...The facility may serve as a replacement of the existing M1 or Morpurgo H8 magnets. The new facility is envisioned to serve all the testing requirements for the next generation of high energy physics particle detectors. Two separate concepts are proposed to satisfy the replacement needs. The magnet will take either the form of a split solenoid, allowing dual use as a dipole or solenoid, or a skateboard tilted racetrack design, allowing dipole function. Both designs allow for at least <inline-formula><tex-math notation="LaTeX">1 \,{\mathrm{m}^{\mathrm{3}}}</tex-math></inline-formula> testing volume and a magnetic field up to 4-T. It is envisioned to use Niobium Titanium Rutherford cables with a Nickel-Aluminium stabiliser. The operation temperature will be 4.5 K with two-phase helium cooling. The stray fields are minimised to stay below 12 mT at a distance of 5 m from the central point.
This perspective paper argues for an urgent need to monitor a set of 12 concrete, measurable indicators of food and water security in the Arctic over time. Such a quantitative indicator approach may ...be viewed as representing a reductionist rather than a holistic perspective, but is nevertheless necessary for actually knowing what reality aspects to monitor in order to accurately understand, quantify, and be able to project critical changes to food and water security of both indigenous and non-indigenous people in the Arctic. More relevant indicators may be developed in the future, taking us further toward reconciliation between reductionist and holistic approaches to change assessment and understanding. However, the potential of such further development to improved holistic change assessment is not an argument not to urgently start to monitor and quantify the changes in food and water security indicators that are immediately available and adequate for the Arctic context.
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