Abstract
Middle East Technical University Defocusing Beam Line (METU-DBL) performs the Single Event Effects (SEEs) radiation tests with protons in the range of 15 MeV to 30 MeV kinetic energy at ...Turkish Atomic Energy Authority Proton Accelerator Facility (TENMAK NÜKEN-PAF) for space and nuclear applications. The most critical beam transfer elements in the METU-DBL are three quadrupole magnets, which are used for defocusing the beam like optical lenses. The first two quadrupole magnets were purchased commercially, and the third quadrupole magnet was designed by the METU-DBL project team and manufactured by Sönmez Transformer Inc. in Turkey. Electronic, mechanic and magnetic capability tests of this custom-designed magnet were conducted both at TUBITAK and CERN facilities. After passing the acceptance tests, the magnet was certified by CERN and then installed to METU-DBL as a third quadrupole magnet. In this paper, we present details of the design, production and performed tests of the quadrupole magnet.
Solar storms and CMEs increase the amount of radiation that reaches the Earth and can perturb the magnetic shielding of the Earth. K and Kp indices quantify this perturbation by using magnetometers ...calibrated accordingly to the latitude of the geomagnetic observatory It is possible to contribute this measurement by establishing an observatory specialized in space weather studies. Many basic sectors are vulnerable against a strong solar storm unless necessary mitigation strategies are applied. Moreover, failure in taking an immediate precaution may have long-term effects which include economic destruction, irreversible health problems and weaknesses in national defence. In this work, the requirement such an observatory should have, the most 11 vulnerable sectors and corresponding mitigation strategies are discussed in detail. Turkey's seven geographical regions are examined to find the optimal location for the foundation of such a probable observatory. It is found that Central Anatolia is the ideal region and districts Konya/Karapinar and Konya/Çeltik are the possible candidates for such a location.
Abstract
The Middle East Technical University Defocusing Beamline
(METU-DBL) is designed to deliver protons with selectable kinetic
energies between 15–30 MeV, and proton flux
between 10
6
–10
10
...protons/cm
2
/s, on a
maximum 21.55 to 15.40 cm target region with a beam uniformity
within ±6%, in accordance with the ESA ESCC No. 25100
specification for single event effects (SEEs) tests in the low
energy range. The achieved high proton fluences, allow users to test
space-grade materials; electronic circuits, ASICs, FPGAs, optical
lenses, structural elements, and coating layers for LEO, GEO, and
interplanetary missions.
The total received dose on the Device-Under-Test (DUT) from
secondary particles created during proton-material interactions at
the first beam collimator and the beam dump never exceed 0.1% of
the dose from primary protons. The METU-DBL is equiped with several
measurement stations and services to the user teams. A secondary
measurement station in a rotating drum that can hold multiple
samples has been constructed next to the first collimator which
provides neutrons for transmission experiments. At the target
region, a robotic table is located, which provides mechanical and
electrical mounting points to the samples and allows multiple
samples to be tested in a row. A modular vacuum box can also be
attached on the robotic table for any test that may require a vacuum
environment. Power rails on the robotic table provide various
outputs for the DUT. For the data acquisition, high-speed networking
and a modular industrial PC are available at the target station. The
design of the METU-DBL control software enables test users to
integrate and optimize the data acquisition and controlling of the
DUT.
The beam properties at the target region are measured with the
diamond, Timepix3, and fiber scintillator detectors mounted on the
robotic table. With diamond and Timepix3 detectors, measurements are
taken from the five different points (center and the four corners)
of the test area to measure the proton flux and ensure that it is
uniform across the full test area. Fiber scintillators on both axes
(X and Y) scan the target area to cross-check the beam profile's
uniformity. Secondary doses during the irradiation are measured by a
Geiger-Müller tube sensitive to electrons and gammas above
0.1 MeV and by a neutron detector located at the entrance of the
R&D room. The room cools down relatively fast after any irradiation
(<1 hour).
Accurate linear energy deposition rates and absorbed doses on the
samples are calculated using MCNP6, FLUKA and Geant4 Monte Carlo
simulations. Alanine dosimetry measurements that are calibrated
against these simulations are also used to estimate the absorbed
dose on the sample.
We report the observation of new properties of primary cosmic rays He, C, and O measured in the rigidity (momentum/charge) range 2 GV to 3 TV with 90×10^{6} helium, 8.4×10^{6} carbon, and 7.0×10^{6} ...oxygen nuclei collected by the Alpha Magnetic Spectrometer (AMS) during the first five years of operation. Above 60 GV, these three spectra have identical rigidity dependence. They all deviate from a single power law above 200 GV and harden in an identical way.
We report on the observation of new properties of secondary cosmic rays Li, Be, and B measured in the rigidity (momentum per unit charge) range 1.9 GV to 3.3 TV with a total of 5.4×10^{6} nuclei ...collected by AMS during the first five years of operation aboard the International Space Station. The Li and B fluxes have an identical rigidity dependence above 7 GV and all three fluxes have an identical rigidity dependence above 30 GV with the Li/Be flux ratio of 2.0±0.1. The three fluxes deviate from a single power law above 200 GV in an identical way. This behavior of secondary cosmic rays has also been observed in the AMS measurement of primary cosmic rays He, C, and O but the rigidity dependences of primary cosmic rays and of secondary cosmic rays are distinctly different. In particular, above 200 GV, the secondary cosmic rays harden more than the primary cosmic rays.
•Machine learning (ML) techniques were pioneered to analyze non-linear relationships.•Algorithm’s predictive power validated ML models, preventing spurious relations.•Recursive feature elimination ...explored predictor importance.•Presence of non-linear relationships is suggested, advising further investigation.•Acknowledgment of skepticism stresses rigorous analysis for long-term correlations.
The Earth’s climate is a complex system that can be influenced by various internal and external factors. Previous research has explored the relationship between climate and external forcings such as solar activity and GCR. However, the relations are intricate and intertwined into almost chaotic meteorological measurements. This paper delves deeper into understanding their interactions. GCR flux, Sunspot number (SSN), total solar irradiance (TSI), UV irradiance (UVI), and the Oceanic Niño Index (ONI) are the predictor variables, while total cloud amount (TCA) and low cloud amount (LCA) are the response variables. The analysis begins with standard statistical techniques and continues with multiple regression models including random forest, which is a machine learning (ML) method that can be used for non-linear regression. Subsequently, Recursive Feature Elimination (RFE) is employed to scrutinize the correlation among the predictor parameters. In the ML model, the final 25% of the dataset is held out and tested for validation, so, the predictive power of the algorithm is measured. Both geographical and temporal patterns have been investigated. This study suggests that a non-linear relationship might exist between the parameters, and should be investigated further, particularly in specific regions of the world.
The potential for protons and ions accelerated by ultra-intense high power laser systems was investigated to perform space radiation tests for electronic components and materials which will be used ...in space. Currently, conventional accelerator systems, which produce monoenergetic particle beams, are employed for space radiation testing. All components must be tested with several different monoenergetic proton and ion beams selected from their continuous energy spectra in space because their broad energy range is a difficult to mimic with discrete energy beams coming from conventional accelerators. Therefore, each component is subjected to at least five different energy proton tests as well as a selection of beams of different ions, which increases the cost of determining the radiation hardness of these components and makes it unpractical. However, laser driven accelerators (LDAs) are capable of producing a mixed environment of particles such as electrons, protons, neutrons, and ions, as well as photons in a wide energy range. The parameters of the laser-plasma interaction can be selected so that the energy spectra and particle fluences of the space radiation environment can be recreated in the laboratory. By using LDA systems, the impact of space radiation on space electronics can be tested using table-top lasers. We performed particle-in-cell (PIC) codes to calculate the energy spectra of accelerated particles via laser plasma interactions. In our simulations, H
+
and C
+6
energy spectra produced from high power laser and plasma interactions were obtained using EPOCH 2D PIC code. These spectra were compared with proton and C
+6
energy spectra and fluences in four different Earth orbits at different altitudes in space, obtained using the NASA AP-8MIN, the CREME-96 and the ESP-PSYCHIC models from the SPENVIS program. The comparisons between the results of EPOCH simulations and SPENVIS look promising in terms of the similarities of these spectra up to 190 MeV for protons and up to 1150 MeV for carbon ions. The idea of using accelerated particles from ultra-intense lasers rather than the conventional accelerator systems is promising for space radiation tests due to their wide energy range.
Precision measurements of cosmic ray positrons are presented up to 1 TeV based on 1.9 million positrons collected by the Alpha Magnetic Spectrometer on the International Space Station. The positron ...flux exhibits complex energy dependence. Its distinctive properties are (a) a significant excess starting from 25.2±1.8 GeV compared to the lower-energy, power-law trend, (b) a sharp dropoff above 284_{-64}^{+91} GeV, (c) in the entire energy range the positron flux is well described by the sum of a term associated with the positrons produced in the collision of cosmic rays, which dominates at low energies, and a new source term of positrons, which dominates at high energies, and (d) a finite energy cutoff of the source term of E_{s}=810_{-180}^{+310} GeV is established with a significance of more than 4σ. These experimental data on cosmic ray positrons show that, at high energies, they predominantly originate either from dark matter annihilation or from other astrophysical sources.
Precision results on cosmic-ray electrons are presented in the energy range from 0.5 GeV to 1.4 TeV based on 28.1×10^{6} electrons collected by the Alpha Magnetic Spectrometer on the International ...Space Station. In the entire energy range the electron and positron spectra have distinctly different magnitudes and energy dependences. The electron flux exhibits a significant excess starting from 42.1_{-5.2}^{+5.4} GeV compared to the lower energy trends, but the nature of this excess is different from the positron flux excess above 25.2±1.8 GeV. Contrary to the positron flux, which has an exponential energy cutoff of 810_{-180}^{+310} GeV, at the 5σ level the electron flux does not have an energy cutoff below 1.9 TeV. In the entire energy range the electron flux is well described by the sum of two power law components. The different behavior of the cosmic-ray electrons and positrons measured by the Alpha Magnetic Spectrometer is clear evidence that most high energy electrons originate from different sources than high energy positrons.
A precision measurement by AMS of the positron fraction in primary cosmic rays in the energy range from 0.5 to 500 GeV based on 10.9 million positron and electron events is presented. This ...measurement extends the energy range of our previous observation and increases its precision. The new results show, for the first time, that above ∼200 GeV the positron fraction no longer exhibits an increase with energy.
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