Charged Cosmic Particles Research Articles

Measurement of the cosmic charged particle rate at sea level in the latitude range 35^{circ }div 82^{circ } N with the PolarquEEEst experiment

After its successful campaign of measurements beyond the Polar Arctic Circle, the PolarquEEEst experiment measured the cosmic charged particle rate at sea level in a latitude interval between 35^{circ } N and 82^{circ } N. In this paper, these measurements are described and the corresponding results are discussed.

Performance of BDX-MINI veto systems

This paper describes the veto system of the BDX-MINI detector installed at Jefferson Lab (US). The BDX-MINI experiment is the first electron beam-dump experiment specifically designed to search for Light Dark Matter (LDM) particles in the MeV-GeV mass range. The core of the BDX-MINI detector is a lead-tungstate electromagnetic calorimeter, for a total volume of 4 dm3. The calorimeter is surrounded by a multi-layer veto aimed at rejecting cosmic background: the innermost layer of the veto is made by a passive tungsten shielding for low energy radiation, while plastic scintillators make the middle and outer layers for charged cosmic particles rejection. Being located about 20 m downstream, the dirt between the beam dump and the detector provides sufficient shielding from the beam-related background. In 2019–2020, BDX-MINI was exposed for about six months to weakly interacting particles (neutrinos and, if existing, DM) produced by a 2.176 GeV electron beam incident on the beam dump of experimental Hall-A at Jefferson Lab.

Measurements and Simulation of background radiation for rare event search experiments at an underground laboratory

Experimental measurements and simulation of various radiation backgrounds at a new underground site have been presented. The experimental cosmic muon flux, measured at this site with the help of a muon telescope set-up, agree well with simulation results after accounting for the geometric effect of the detector assembly. The gamma ray background inside the laboratory space was measured to assess and optimize the required thickness of Lead for shielding. Neutrons, produced in the surrounding rock due to radioactive decay, followed by nuclear reactions with the rock constituents, and the faster neutrons, produced through interaction of the charged cosmic particles, propagate through the rock material to reach inside the laboratory. The neutron background flux was measured and GEANT4 simulations were carried out. The results were found to be in reasonable agreement with measurements.

Анализ работоспособности электродинамических тросов с автономной генерацией электронов

Currently, electric rocket engines have largely reached the efficiency limits determined by the principle of rocket thrust. Electrodynamic tethers, interacting with an external magnetic field and actually being jet engines, are devoid of such restrictions. However, their thrust is limited by the concentration of the external plasma and depends on its fluctuations. The paper is the first to propose to create a current in the tether by propellant ionization, receiving a large thrust from a relatively short tether and a strong magnetic field deflecting charged cosmic particles. The numerical analysis showed that the length of the tether of hundreds of meters near the Earth provides a specific impulse of up to hundreds of kilometers per second and its proper acceleration of the power plant at a level of 0.01 m / s2, as well as protection of the central region of the tether from particles with an energy of more than 1 MeV. This makes it possible to consider it for maneuvering satellites with practically no restrictions on the delta-V, for performing fast high-energy inter-orbital flights and for radiation protection of a high-latitude orbital station. In the future, such a tether can be used for rapid deceleration of orbital objects, launching into geostationary orbit, interplanetary transfers and protection of objects from charged particles. The study describes possible areas of application and directions for further research of the concept of such a tether.

New high precision measurements of the cosmic charged particle rate beyond the Arctic Circle with the PolarquEEEst experiment

The goal of the PolarquEEEst experiment was to measure the cosmic charged particle rate at latitudes greater than 66^{circ } N, where no systematic and accurate measurements at sea level have ever been performed. A latitude range well above the Arctic Circle was explored on board of a sailboat, up to the unprecedented northernmost value of 82^{circ }07^{prime } N. In this paper a description of the experimental set-up is reported, then the procedures for calibration and data analysis are described in detail. The results show that the rate measured in this latitude range stays constant within a novel accuracy of pm 1%.

The Phonon-Mediated TES Cosmic Ray Detector for Focal Plane of ATHENA X-Ray Telescope

The current projects of future X-rays space telescopes foresee high resolving power transition edge sensor (TES) micro-calorimeters arrays as focal plane instrument. In order to full exploit their sensitivity in the space environment, they need an anticoincidence detector to reject the background due to cosmic charged particles. High-energy protons (> 150 MeV) and other charged particle may release in the X-ray calorimeter, the same energy of the X-rays sources under observation. We report the description of the last prototype based on TES calorimeter where a 1-cm2 silicon chip is used as both substrate and absorber. The readout is made of 96 iridium/gold TESs uniformly distributed on its surface and parallel wired. In this paper, we will describe the design, with the preliminary phonon dynamics simulation, the fabrication, of first demonstration model for the ATHENA space telescope project.

The IACT Optical System of the TAIGA Observatory Complex

TAIGA (Tunka Advanced Instrument for Gamma Astronomy) is designed for studying gamma rays and charged cosmic particles in the energy range of 1013–1018 eV. The staff of the Joint Institute for Nuclear Research is now working on the design and fabrication of Cherenkov telescope elements (IACTs). The IACT field of view is ~10° × 10°, due to a Davis–Cotton optical layout with 34 mirrors 0.60 m in diameter, a focal length of 4.75 m, and 560 XP1911 PMT camera. The first IACT was commissioned in 2016 in the Tunka Valley. The second IАСТ is now being prepared for operation. The steps of PMT alignment and the results from its calibration are thoroughly described along with the fabrication of a mirror and its optical parameters. The technique for adjusting the mirror is presented as well. It replaces the conventional visual assessment of the image with pattern recognition software that is applied to a screen shot of the calibration source. This software ensures highly precise calculations of the mirror’s adjusting screws to obtain a correct image.

Multifunctional Cosmic-Ray Shielding of Spacecraft with Elements of Systems Engineering Design

A systems engineering approach is applied to design and propose a solution for reducing the exposure of astronauts to galactic cosmic rays in space exploration beyond the magnetosphere of Earth. The proposed design is based on the deflection of high-energy charged cosmic particles (protons, alpha particles, electrons, etc.) by the electrostatic field created by multiplate low-energy capacitors surrounding the habitat capsule of a spacecraft. In this design, the electrical field outside the capacitors is negligibly small, which prevents the attraction of charged particles from the outer space to the spacecraft and does not affect the astronauts inside. Because the proposed shielding was designed to deflect any sort of charged particles and not to stop them, the design does not require thick and heavy materials to protect the spacecraft. In addition to active shielding by the electrostatic field of light capacitors, it is also proposed that the habitat capsule be surrounded by passive shielding “sandwichlike” multilayers of novel ultralight materials filled with hydrogen. Because of this, the proposed design is relatively lightweight, made of low-cost materials, simple to build and assemble, easily scalable to smaller or larger sizes or energy, and repeatable for double or multiple layers. In addition, a technique of using the cosmic charged particles to charge the capacitors as an additional supply of energy for the shielding system function and spacecraft operation is proposed.

Promising Neutron Detector with Anticoincidence Protection

The method of remote neutron and gamma spectrometry of bodies in the solar system (the Moon, Mars, and Mercury) has been used for several decades to estimate the nuclear composition of these objects and the hydrogen abundance in their subsurface layers. Proportional gas counters based on helium-3 (3He), which have the maximum efficiency of detecting thermal and epithermal neutrons, are used most often for measuring the low-energy neutron component. However, the data from LEND and FREND space experiments with large-volume and high-pressure helium counters revealed the noise contamination of lower channels of the neutron component due to the sensitivity of such counters to cosmic charged particles. The model of a promising neutron detector with anticoincidence protection, which is free from this drawback, is presented below.

Architecture of Distributed Data Storage for Astroparticle Physics

For the successful development of the astrophysics and, accordingly, for obtaining more complete knowledge of the Universe, it is extremely important to combine and comprehensively analyze information of various types (e.g., about charged cosmic particles, gamma rays, neutrinos, etc.) obtained by using divers large-scale experimental setups located throughout the world. It is obvious that all kinds of activities must be performed continually across all stages of the data life cycle to help support effective data management, in particular, the collection and storage of data, its processing and analysis, refining the physical model, making preparations for publication, and data reprocessing taking refinement into account. In this paper we present a general approach to construction and the architecture of a system to be able to collect, store, and provide users’ access to astrophysical data. We also suggest a new approach to the construction of a metadata registry based on the blockchain technology.

Orders of Magnitude of the Fermi and Plasma Accelerations of Cosmic Rays

The generic acceleration model for ultra high energy cosmic rays, which has been introduced in Ref [?], suggests various types of electromagnetic interactions between cosmic charged particles and the different types of the plasma fields, which are assumed to have general configurations, spatially and temporally. The well-known Fermi acceleration mechanisms are also included in the model. Meanwhile Fermi mechanisms in non-relativistic limit adhere firstand second-order of magnitude of β , the ratio of particle’s velocity relative to the velocity of the stellar magnetic cloud, in the plasma field sector, β does not play any role, i.e. zero-order. In the relativistic limit, the orders of magnitude of Fermi acceleration are only possible, when applying the corresponding conditions, either elastic scatterings or shock waves. Furthermore, it is found that the coefficients of β are functions of the initial and final velocities and the characteristic Larmor radius.

MICMOC/MICMOS: Photochemistry of van der Waals solids and the rise of the organic molecular complexity

Ices of well-known composition are widely observed in molecular clouds out of which stars, planets and debris (asteroids, comets) will form. These ices are naturally subjected to energy input in the form of UV photons and charged cosmic particles which are able to start a very rich radical chemistry in the solid state. These phenomena are simulated in the MICMOC experiment which focuses on the possible prebiotic significance of the organic residues that are formed at room temperature. Further than MICMOC, we propose a general prospective of the evolution of this experiment toward the concept of non-directed experiments that may allow simulating the very first steps from the inanimate molecular world to selective pathways toward self-replicating autocatalytic and heterotrophic molecules that could be considered, for a physicist a template for “minimal” life.

ACCELERATION AND PARTICLE FIELD INTERACTIONS OF COSMIC RAYS II: CALCULATIONS

The Ultra High Energy Cosmic Rays (UHECRs) is still a one of the most controversial physical problems, especially that all potential acceleration mechanis ms are not entirely able to explain the source of U HECR and their energy scale. Based on our generic accele ration model, that suggests different types of electromagnetic interactions between the cosmic cha rged particles and the different configurations of the electromagnetic (plasma) fields, UHECR are systematically analyzed. The plasma fields are assumed to vary, either spatially or temporally or both. In th is approach, the well-known Fermi accelerations are excluded. But seeking for simplicity, it is assumed that the energy loss due to the different physical processes is negligibly small. The energy available to the plasma sector is calculated in four types o f electromagnetic fields. It is found that the drift in a time-varying magnetic field is extremely energ etic and the energy scale widely exceeds the Greisen-Zatsepi n-Kuzmin (GZK) cutoff. We deduced that the polarization drifts in a time-varying electric fiel d is also able to raise the energy of UHECR to an e xtreme value. Thus, this type of generic mechanisms seems to be combatiple with the Hillas mechanism. The dri ft in a spatially-varying magnetic field is almost as strong as the polarization drift. The curvature dri ft in a non-uniform magnetic field and a vanishing electric field is very weak . It is to be concluded that the studying cosmic charged particle interactions with the different aspects of the cosmic plasmas could b e considered as intrinsic sources for UHECR and there fore a remarkable portion of the ultra high energie s that are observed in the cosmic rays can be interpreted.

INFLUENCE OF TURBULENCE DISSIPATION EFFECTS ON THE PROPAGATION OF LOW-ENERGY COSMIC RAYS IN THE GALAXY

The propagation of cosmic rays in the Galaxy is controlled by spatial diffusion coefficients. Since parallel scattering is the strongest scattering effect, it is believed that the diffusion coefficient along the mean magnetic field controls the confinement of charged cosmic particles in the Galaxy. In this paper, we combine a turbulence spectrum with dissipation range with a nonlinear particle diffusion theory to compute transport parameters. We find a decreasing parallel diffusion coefficient for increasing particle energy for particles having rigidities lower than 3 GeV. Our approach provides an explanation of the observed boron-to-carbon ratio at these particle energies without the need to introduce stochastic acceleration.

Measurements of Antarctic ice properties for acoustic neutrino detection

Detection of the faint flux of neutrinos from interactions of the highest energy charged cosmic particles with microwave background photons with a reasonable number of events would contribute to answering interesting questions of particle physics as well as astro-particle physics and cosmology. This needs however detector volumes 100 times larger than the biggest optical neutrino telescopes presently under construction. The use of at least two technologies with different systematics would help to fight the large background expected to hide the small signal.A hybrid optical-radio-acoustic array suggested around the IceCube observatory at the South Pole seems to be a promising option for such an experiment. This is the reason for an extensive evaluation of the acoustic properties of the ice at the Pole with the help of the South Pole Acoustic Test Setup – SPATS.SPATS consists of four strings with seven acoustic stations each, deployed in the upper part of IceCube bore-holes down to 400 m to 500 m depth. Each acoustic station has an acoustic transmitter and three acoustic receivers. Data have been taken with since early 2007. During the last Austral summer in addition a movable transmitter was used in several water filled bore-holes aiming in particular for a relative calibration of the setup. Preliminary results are presented on speed of sound versus depth, noise behavior and attenuation length measurements

Recent results from the MAGIC telescope

Ground-based γ -ray astronomy is part of a new field of fundamental research of Astroparticle Physics that recently made spectacular discoveries. Nearly all important discoveries have been made by imaging air Cherenkov telescopes (IACT) which allow one to detect Cherenkov light from extended air showers initiated by cosmic γ -rays and charged cosmic particles. The MAGIC telescope is a new generation IACT located at La Palma, Canary Islands, Spain (28.3°N, 17.8°W, 2240 m asl). Currently MAGIC is the world's largest single-dish IACT (with a 17 m diameter), and it has a trigger energy threshold of 50 GeV. Since MAGIC started to operate in 2004, eight galactic and eleven extragalactic sources and many new physics features of known sources have been detected. Here are presented some highlights from the most recent results in 2006/2007.

The Ring Imaging Cherenkov detector of the AMS experiment: test beam results with a prototype

The Alpha Magnetic Spectrometer (AMS) to be installed on the International Space Station (ISS) will be equipped with a proximity Ring Imaging Cherenkov (RICH) detector for measuring the velocity and electric charge of the charged cosmic particles. This detector will contribute to the high level of redundancy required for AMS as well as to the rejection of albedo particles. Charge separation up to iron and a velocity resolution of the order of 0.1% for singly charged particles are expected. A RICH protoptype consisting of a detection matrix with 96 photomultiplier units, a segment of a conical mirror and samples of the radiator materials was built and its performance was evaluated. Results from the last test beam performed with ion fragments resulting from the collision of a 158 GeV/c/nucleon primary beam of indium ions (CERN SPS) on a lead target are reported. The large amount of collected data allowed to test and characterize different aerogel samples and the sodium fluoride radiator. In addition, the reflectivity of the mirror was evaluated. The data analysis confirms the design goals.

Clean room design considerations for deep-underground science and engineering laboratories

This paper presents the factors that affect the clean room shielding design at the deep-underground science and engineering laboratory (DUSEL), for enhancing detection of weakly interacting massive particles (WIMP), neutrino or double beta decay signals. The goal of the shielded clean room is to minimize the neutron and gamma-ray background and spurious signals, including secondary particles generated within shielding materials, permitting increased probability of detection of signals arising from WIMP and other particles of interest. Various arrangement options of shielded blocks made of paraffin and lead are examined to reduce the background from intrinsic uranium/thorium trace sources and high energy charged cosmic particles that interact with passive shielding material. A new shield block material is proposed and compared with other ordinary shield block arrangements currently used in detector passive shielding designs.

The use of a syncytium model of the crystalline lens of the eye as a new tool to study the light flashes phenomenon seen by astronauts

A syncytium model to study some electrical properties of the eye is proposed to study the phenomenon of anomalous light flashes (LF) perceived by astronauts in orbit. The crystalline lens is modelled as an ellipsoidal syncytium with a variable relative dielectric constant. The corresponding mathematical model is a boundary value problem for a system of two coupled elliptic partial differential equations in the two unknown syncytial electrical potentials. A numerical method to compute an approximate solution of this mathematical model is used, and some numerical results are shown. The model can be regarded as a new tool to study the LF phenomenon. In particular, the energy lost in the syncytium by a transversing cosmic charged particle is calculated and the results obtained with the syncytium model are compared with those obtained using the previously available Geant 3.21 simulation program. In addition, the interaction of antimatter-syncytium is studied, and the Creme96 computer program is used to evaluate the cosmic ray fluxes encountered by the International Space Station in its standard mission.

Cosmic Ray and UV Radiation Models on the Ancient Martian Surface

The atmospheric evolution on Mars is influenced by nonthermal loss processes of heavy atmospheric constituents. Since Mars does not have an appreciable intrinsic magnetic field at present and a comparatively small gravitational acceleration, all known atmospheric loss processes can be active and several important constituents are lost to space. The escape rates of atmospheric constituents including water from Mars indicate that the red planet could have lost an atmosphere of at least 1 bar to space during the past 3.5 Gyr. We investigated with a theoretical model the atmospheric flux of cosmic-ray-induced particles on the martian surface by solving Boltzmann equations governing the propagation of protons, neutrons, muons, and pions in 7-mbar and 1-bar CO 2 atmospheres. We found that, at present, the thin atmosphere is not able to protect the surface of Mars from cosmic radiation and most of the incoming protons and neutrons impact the ground with energy fluxes of about 6000 and 1400 MeV cm −2 s −1, respectively. On the other hand, the much denser ancient atmosphere attenuated the radiation and only secondary particles, mainly muons, were able to reach the surface with energy fluxes of about 100 MeV cm −2 s −1, while the fluxes of protons and neutrons were negligible. We also evaluated the influence of an intrinsic magnetic field on the magnitude of the surface flux of charged cosmic particles and found no effect, even if one assumes an Earth-type magnetic field on ancient Mars, as suggested by recent Mars Global Surveyor magnetometer data. In addition we investigated the shielding of the martian surface from ultraviolet (UV) radiation by a dense early 1-bar CO 2 atmosphere including additional absorption effects of O 2 and O 3 and Rayleigh scattering. This atmosphere gradually becomes transparent to UV radiation above wavelengths of 220 nm.