Polarized Fusion. Can Polarization Help to Increase the Energy Output of Fusion Reactors?

Since more than 60 years scientists are working on the idea to produce energy from nuclear fusion of light particles like the Hydrogen isotopes. In the meantime, the energy output of e.g. tokamak reactors was increased by five orders and modern experiments like JET are approaching the border for energy production. The international ITER collaboration is preparing the first fusion reactor that will produce about ten times more energy, compared to the energy that is needed to run the experiment. Today, the laser-induced inertial fusion reached the same level and experiments at the National Ignition Facility (NIF) in California, USA, demonstrate a ratio between produced and induced energy about one at the end of 2013.1 In parallel, it is discussed since 1970 to use nuclear polarized fuel to increase the total cross sections of the different fusion reactions.2 The energy gain of fusion reactors does not depend linearly on the total cross section. Depending on the different concepts for nuclear fusion, magnetic confinement or inertial fusion, the energy gain This is an Open Access article published by World Scientific Publishing Company. It is distributed under the terms of the Creative Commons Attribution 3.0 (CC-BY) License. Further distribution of this work is permitted, provided the original work is properly cited. 1660112-1 Int. J. Mod. Phys. Conf. Ser. 2016.40. Downloaded from www.worldscientific.com by UNIVERSITY OF FERRARA on 04/19/16. For personal use only. R. Engels & G. Ciullo is improved above average. M. Temporal et al. have shown, e.g., that the energy gain of laser-induced inertial fusion might be increased by a factor four, or that the necessary laser power can be reduced by 20 %, if the nuclear fuel was polarized before.3 The downsized laser power will reduce the costs of the corresponding project by a reasonable amount. In addition, the differential cross sections can be modified so that it will be possible to focus the ejectiles, e.g. the neutrons, on special wall areas. In a tokamak this can be used to concentrate the neutron flux to special outer parts of the blanket, where the cooling can be improved and the neutrons be used for Tritium production via the exothermic reaction 6Li+n → 4He+t.4 At the same time, less cooling is needed for the inner parts of the blanket that allows to bring the magnetic field coils closer to the fusion plasma. The increased magnetic field in the plasma will increase the energy gain additionally. Another option of polarized fuel is a new kind of plasma diagnostic inside a tokamak. In combination with modern Nuclear Magnetic Resonance technologies (NMR) anisotropies in the plasma can be measured to learn more about the different plasma mode

Polarized Fusion. Can Polarization Help to Increase the Energy Output of Fusion Reactors

For more than 50 years it has been discussed to increase the gain of nuclear fusion reactors with the use of polarized fuel. For example, the total cross secti ons of the most interesting fusion reactions d+ t ! 4 He+n or 3 He+d ! 4 He+p are increased by 50% if the spins of both incoming particles are aligned. This effect will increase the energy output of a fusion reactor more than linearly, e.g. by a factor 4. However, before polarized fuel can be used for energy production in the different types of reactors, a number of questions must be answered. In this contribution we give an overview on our various activities in this field of res earch

The H and D Polarized Target for Spin–Filtering Measurements at COSY

In the main frame of the PAX (Polarized Antiproton eXperiments) collaboration, which engaged the challenging purpose of polarizing antiproton beams, the possibility to have H or D polarized targets requires a daily switchable source and its diagnostics: mainly change is a dual cavity tunable for H and D. The commissioning of PAX has been fullfilled, for the transverse case, on the COSY (COoler SYnchrotron) proton ring, achieving milestones on spin–dependent cross–section measurements. Now the longitudinal case could provide sensitive polarization results. An H or D source allows the exploration of the spin–filtering process with a deuterium polarized target, and opens new chances for testing Time Reversal Invariance at COSY (TRIC)

Human-flood interactions in Rome over the past 150 years

Abstract. Throughout history, the socio-economic development of the city of Rome has been intertwined with the magnitude and frequency of flooding events from the Tiber, one of Italy's largest rivers. Ancient Rome mostly developed on the hills, while the Tiber's floodplain was mainly exploited for agricultural purposes. A few small communities did settle in the riparian areas of the Tiber, but they had a relatively peaceful relationship with the frequent occurrence of flooding events. Instead, numerous people live nowadays in modern districts in the Tiber's floodplain, unaware of their exposure to potentially catastrophic flooding. This research work aims to explore the dynamics of changing flood risk between these two opposite pictures of ancient and contemporary Rome. To this end, we carried out a socio-hydrological study by using long time series of hydrological (extreme flood events) and social (human population dynamics) processes, along with information about human interactions with the environment (flood defence structures). The historical analysis showed how human and water systems have been co-evolving over time, while being abruptly altered by the occurrence of an extreme flood event in 1870, just before Rome became the capital of a recently unified Italy. The outcomes of this study were then compared to the results of a socio-hydrological model simulating the dynamics emerging from the mutual shaping of floods and societies

Design Consideration on a Polarized Gas Target for the LHC

Since 2017, the LHCSpin study group is investigating the installation of a HERMES-type polarized gas target (PGT) in front of the LHCb detector in order to perform Single-Spin Transverse Asymmetry (SSTA) measurements. In cooperation with LHC experts, the conditions for applying a PGT are being studied. As a viable option, a cold openable storage cell is considered. A key role for avoiding instabilities of the 7 TeV proton beam is the choice of a proper coating and the suppression of wake fields. A first warm (300 K) test storage cell is planned for installation in 2019 inside the VELO vessel, subject to final approval. It will improve the ongoing SMOG program of LHCb fixed target measurements, and will provide valuable experience of running a storage cell in the harsh LHC environment. The status of the design considerations on a PGT in the LHC beam and of the discussion of critical machine issues is presented.Comment: 8 pages, 7 figures, 11 reference

Erratum: Inflammatory extracellular vesicles prompt heart dysfunction via TLR4-dependent NF-κB activation: Erratum.

[This corrects the article DOI: 10.7150/thno.39072.]

L'esitazione di un Dio che si nasconde

Questo libro nasce dall'idea di condividere alcune riflessioni sull’umano e sul divino, a partire da tutte quelle voci, sguardi, segni, che continuamente entrano nella nostra vita. Ci sono voci che semplicemente ci svuotano, altre invece che ci risvegliano e ci cambiano per sempre. Anche l'eterno ha una voce sua, un suo sguardo e lascia dei segni sulla nostra anima ma anche sul nostro corpo. Non sempre è facile seguirne le tracce perché spesso sono così simili a tutte le altre. Talvolta lasciarsi raggiungere da questa Voce permette di ritrovare il fascino il calore di quel salutare mistero che tante immagini e parole su Dio non riescono più a comunicare.This book was born from the idea of sharing some reflections on the human and the divine, starting with all those voices, looks, signs that continually enter our life. There are voices that simply empty us, others instead that awaken us and change us forever. Even the eternal has its own voice, its own look and leaves marks on our soul but also on our body. It is not always easy to follow their tracks because they are often so similar to all the others. Sometimes allowing oneself to be reached by this Voice allows one to rediscover the charm and warmth of that salutary mystery that so many images and words about God are no longer able to communicate

First Search for Axion-Like Particles in a Storage Ring Using a Polarized Deuteron Beam

Based on the notion that the local dark-matter field of axions or axion-like particles (ALPs) in our Galaxy induces oscillating couplings to the spins of nucleons and nuclei (via the electric dipole moment of the latter and/or the paramagnetic axion-wind effect), we performed the first experiment to search for ALPs using a storage ring. For that purpose, we used an in-plane polarized deuteron beam stored at the Cooler Synchrotron COSY, scanning momenta near 970 MeV/c. This entailed a scan of the spin precession frequency. At resonance between the spin precession frequency of deuterons and the ALP-induced EDM oscillation frequency there will be an accumulation of the polarization component out of the ring plane. Since the axion frequency is unknown, the momentum of the beam and consequently the spin precession frequency were ramped to search for a vertical polarization change that would occur when the resonance is crossed. At COSY, four beam bunches with different polarization directions were used to make sure that no resonance was missed because of the unknown relative phase between the polarization precession and the axion/ALP field. A frequency window of 1.5-kHz width around the spin precession frequency of 121 kHz was scanned. We describe the experimental procedure and a test of the methodology with the help of a radiofrequency Wien filter located on the COSY ring. No ALP resonance was observed. As a consequence an upper limit of the oscillating EDM component of the deuteron as well as its axion coupling constants are provided.Comment: 25 pages, 24 figures, 7 tables, 67 reference

A large, curated, open-source stroke neuroimaging dataset to improve lesion segmentation algorithms.

Accurate lesion segmentation is critical in stroke rehabilitation research for the quantification of lesion burden and accurate image processing. Current automated lesion segmentation methods for T1-weighted (T1w) MRIs, commonly used in stroke research, lack accuracy and reliability. Manual segmentation remains the gold standard, but it is time-consuming, subjective, and requires neuroanatomical expertise. We previously released an open-source dataset of stroke T1w MRIs and manually-segmented lesion masks (ATLAS v1.2, N = 304) to encourage the development of better algorithms. However, many methods developed with ATLAS v1.2 report low accuracy, are not publicly accessible or are improperly validated, limiting their utility to the field. Here we present ATLAS v2.0 (N = 1271), a larger dataset of T1w MRIs and manually segmented lesion masks that includes training (n = 655), test (hidden masks, n = 300), and generalizability (hidden MRIs and masks, n = 316) datasets. Algorithm development using this larger sample should lead to more robust solutions; the hidden datasets allow for unbiased performance evaluation via segmentation challenges. We anticipate that ATLAS v2.0 will lead to improved algorithms, facilitating large-scale stroke research