The observation of sub-GeV antideuteron in the cosmic ray flux, could be a very strong signature of dark matter annihilation in our galaxy. Goal of the Anti Deuteron Helium Detector (ADHD) project is ...to study the signatures offered by an high pressure Helium target for the identification of antideuterons in space.
The observation of sub-GeV antideuteron in the cosmic ray flux could be a very strong signature of dark matter (DM) annihilation in our galaxy. The predicted antideuteron flux resulting from ...secondary interactions of primary cosmic rays with the Inter-Stellar medium is expected to be very low and in particular is kinematically suppressed at low energy (sub-GeV). Well motivated theories beyond the Standard Model contain viable dark matter candidates, which could lead to a significant enhancement of the antideuteron flux due to annihilation or decay of dark matter particles. This flux contribution is believed to be relatively large at low energies, where the secondary background is suppressed, which leads to an high interest in the development of new detection techniques for low energy antideuteron. Current search of antideuteron in cosmic rays are based on the well established technique of magnetic spectrometry (BESS-Polar II and AMS-02 experiments). With the aim to explore kinetic energy regions below 0.2 GeV/n, i.e. below the lower threshold of current and past magnetic spectrometers, some new detection techniques, involving stopping antideuterons captured to form exotic atoms, have been developed. The GAPS experiment, based on the detection of characteristics X-rays, and the ADHD concept, based on the metastable states in Helium target, will be described. In particular the performances of an high pressure (200 bar) Helium scintillator prototype, capable of fast timing and good spatial and energy resolution will be shown. As a result of the preliminary test phase of this prototype in the INFN-TIFPA laboratory, the perspectives of this detection technique for antiproton rejection and its sensitivity to the Dark Matter search in the antideuteron annihilation channel will be described.
The deuteron flux in cosmic rays is one of the most valuable tools for understanding the propagation of CR in the galaxy and constrain the models that describe it. In this work, a new preliminary ...measurement of D flux is presented, obtained from the data of the AMS-02 experiment.
The future Laser Interferometer Space Antenna (LISA) for gravitational wave detection in space and the precursor LISA Pathfinder missions rely on metal test masses (TMs) playing the role of ...free-falling geodesic-reference and interferometer end mirrors. Charge deposited on the TMs by high-energy particles of galactic and solar origin couples with stray electric fields thus perturbing the free-falling geodesic motion. In previous works it has been shown that sub-keV electrons play a relevant role for TM charging. In particular, electrons with energies below 100 eV show a wave-like behavior when impacting on the gold coatings of the TMs and electrode-housing (EH), the capacitive position sensor/actuator that surrounds the TMs. We aim at studying the effects of quantum diffraction of electrons on LISA Pathfinder and LISA TMs and EH gold lattice. We calculate the quantum diffraction probability of electrons with energies < 100 eV impinging on gold lattice from different directions by using the methods of quantum mechanics. The effects of electron quantum diffraction on LISA TM charging are reported here for the first time. This work is also of interest for the second-generation LISA-like space interferometers and for all space missions whose performance relies on free-falling metal test masses.
•Spurious Coulomb forces act on the space interferomter metal test-masses due to the charging process induced by galactic cosmic rays and solar energetic particles.•Low-energy electromagnetic physics, lacking in the main Monte Carlo programs for particle propagation in matter, plays a major role for the estimate of the test-mass charging in space interferometers.•We calculate the probability of diffraction for electrons impacting on gold surfaces below 100 eV.•We apply the results of the calculation to the test-mass charging estimate for LISA.
Abstract
The Outreach Cosmic Ray Activities (OCRA) project was created in 2018 within the Italian Istituto Nazionale di Fisica Nucleare (INFN) to offer a platform for all outreach activities focusing ...on cosmic rays within the institute. OCRA now counts 22 of the institute’s divisions all over Italy as members. The project offers activities both for students and teachers. The one activity common to all local groups is the participation in the yearly International Cosmic Day, organized by DESY, inviting high school students to carry out hands-on measurements of the cosmic ray flux and learn about the related physics background. Two students from each division are then selected to participate in the annual OCRA science camp, a three-day full immersion into the life of a physicist. For both teachers and students, the OCRA website https://web.infn.it/OCRA/, offers a series of online laboratories designed both to be used by students individually but also to be offered in the classroom by teachers. A section dedicated to teachers provides ample material to help bring these laboratories to the classroom. The online materials were presented in a course for teachers in spring 2021. In addition to the national efforts, there are also local initiatives of the OCRA member groups: workshops and secondments, science competitions and the development of new detectors for outreach activities offer a multitude of possibilities for students to engage with our researchers and to explore the world of cosmic rays. This article provides an overview on all activities offered by OCRA with a particular focus on the 2022 science camp.
The deuteron (D) over proton (p) flux ratio in cosmic rays (CR) is one of the most valuable tools for understanding the propagation of CR in the galaxy and constrain the models that describe it. In ...this work, two new preliminary measurement of D/p flux ratios is presented, each obtained from the data of the AMS-02 experiment.
The measurement of light isotope components in cosmic rays (CR) like3He,2H (D)and6Li are some of the most valuable tools for understanding the propagation of CR in the galaxy and constrain the models ...that describe it. In this work a new preliminary measurement of3He/4He,6Li/7Li and D/p flux ratios are presented, each obtained from the data of the AMS-02 experiment, along with the measurement of the isotopic component fluxes.
Nowadays, most biodiesel (fatty acids methyl esters, FAME) is produced by the transesterification of triglycerides (TG) of refined/edible type oils using methanol and an homogeneous alkaline ...catalyst. However, production costs are still rather high compared with the ones of petroleum-based diesel fuel. To lower costs and make biodiesel competitive less-expensive feedstocks such as waste fats or non-edible type oils could be used. The use of homogeneous alkaline catalysts in the transesterification of such types of fats and oils poses great difficulties due to the presence of large amounts of free fatty acids (FFA). This paper studies the use of carboxylic salts as a possible alternative, because these catalysts are active also in the presence of high FFA concentrations.
The most active catalyst (Cd, Mn, Pb, Zn carboxylic salts) have been individuated and a correlation of the activities with the cation acidity has been found.
The use of classical alkaline catalysts in the transesterification of waste fats and oils to obtain fatty methyl esters (FAME) poses great difficulties due to the presence of large amounts of free fatty acids (FFA). This paper studies as a possible alternative, the use of different bivalent metals. The most active catalysts have been individuated and a correlation of the activities with the cation acidity has been found.
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Bisphosphonates such as zoledronic, alendronic and risedronic acids are a class of drugs clinically used to prevent bone density loss and osteoporosis. Novel P-C-P bisphosphonates were synthesized ...for targeting human farnesyl pyrophosphate synthase (hFPPS) and human geranylgeranyl pyrophosphate synthase (hGGPPS), key enzymes of the mevalonate pathway, and capable of anti-proliferative action on a number of cell lines (PC3, MG63, MC3T3, RAW 264.7, J774A.1, bone marrow cells and their co-colture with PC3) involved in bone homeostasis, bone formation and death. Among sixteen compounds, 1-hydroxy-2-(pyrimidin-2-ylamino)ethane-1,1-diylbis(phosphonic acid) (10) was effective in reducing PC3 and RAW 264.7 cell number in crystal-violet and cell-dehydrogenase activity assays at 100 μM concentration. 10 reduced differentiated osteoclasts number similarly with zoledronic acid in osteoclastogenesis assay. At nanomolar concentrations, 10 was more effective than zoledronic acid in inducing mineralization in MC3T3 and murine bone marrow cells. Further, 10 significantly inhibited the activity of hFPPS showing an IC50 of 0.31 μM and a remarkable hydroxyapatite binding of 90%. Docking calculations were performed identifying putative interactions between some representative novel bisphosphonates and both hFPPS and hGGPPS. Then, 10 was found to behave similarly or even better than zoledronic acid as a anti-resorptive agent.
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•Bisphosphonic acids (N-BPs) were synthesized with fair to good yields.•hFPPS and hGGPPS were produced and purified.•Pyrimidine- and quinazoline-N-BPs were tested as hFPPS and hGGPPS inhibitors.Zoledronate and pyrimidine-N-BP (py-N-BP) show a similar anti-proliferative profile.•py-N-BP induces osteoblast mineralization and restorative osteoblastogenesis effect.
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