Search results for " LAB"

Latvijas Universitātes Bibliotēkas jaunumi, 2016, Nr. 10

2016

Kriminālatbildība par prettiesiska labuma pieņemšanu un došanu

2018

Maģistra darba tēma ir “Kriminālatbildība par prettiesiska labuma pieņemšanu un došanu”. Šī darba mērķis ir izpētīt prettiesiska labuma pieņemšanas un došanas aspektus un normatīvo regulējumu Latvijā, konstatējot tā pietiekamību, un šajā sakarā pastāvošo problemātiku. Lai sasniegtu mērķi, ir izvirzīti sekojoši uzdevumi: 1) veikt Krimināllikuma 326.2 un 326.3 pantos ietvertā prettiesiskā labuma teorētisko izpēti; 2) raksturot prettiesisku labumu un tajā ietilpstošo materiālo, mantisko un citāda rakstura labumu veidus; 3) definēt valsts un pašvaldību iestādes darbinieka skaidrojumu; 4) analizēt prettiesiska labuma kā 326.2 un 326.3 pantos minētā noziedzīgā nodarījuma sastāvu, tai skaitā subje…

DNP in MRI: an in-bore approach at 1.5 T.

2011

Abstract We have used liquid state (“Overhauser”) Dynamic Nuclear Polarization (DNP) to significantly enhance the signal to noise ratio (SNR) of Magnetic Resonance Imaging (MRI). For the first time this was achieved by hyperpolarizing directly in the MRI-scanner field of 1.5 T in continuous flow mode and immediately delivering the hyperpolarized substance to the imaging site to ensure maximum contrast between hyperpolarized sample and sample at thermal polarization. We achieve a maximum absolute signal enhancement factor of 98; while the hyperpolarized sample is transported at a flow rate of up to 30 ml/h yielding an average flow speed up to 470 mm/s over a distance of approximately 80 mm. …

A pulsed high-voltage decelerator system to deliver low-energy antiprotons

2021

International audience; The GBAR (Gravitational Behavior of Antihydrogen at Rest) experiment at CERN requires efficient deceleration of 100 keV antiprotons provided by the new ELENA synchrotron ring to synthesize antihydrogen. This is accomplished using electrostatic deceleration optics and a drift tube that is designed to switch from -99 kV to ground when the antiproton bunch is inside – essentially a charged particle “elevator” – producing a 1 keV pulse. We describe the simulation, design, construction and successful testing of the decelerator device at -92 kV on-line with antiprotons from ELENA.

Effect of double frequency heating on the lead afterglow beam currents of an electron cyclotron resonance ion source

2017

International audience; The effect of double frequency heating on the performance of the CERN GTS-LHC 14.5 GHz ElectronCyclotron Resonance (ECR) ion source in afterglow mode is reported. The source of the secondary microwave frequency was operated both in pulsed and continuous wave (CW) modes within the range of 12–18 GHz. The results demonstrate that the addition of the secondary frequency can significantly impact the extracted beam currents and the temporal stability of the beam during the afterglow discharge. For example, up to a factor of 2.6 increase was achieved for 208Pb35+ and a factor of 3.1 for 208Pb37+ compared to single frequency afterglow currents. It is shown that these effect…

β-delayed neutron emission of r-process nuclei at the N = 82 shell closure

2021

This experiment was performed at RI Beam Factory operated by RIKEN Nishina Center and CNS, University of Tokyo. O.H, T.D, P.J.W, C.G.B, C.J.G and D.K would like to thank STFC, UK for support. This research was sponsored in part by the Office of Nuclear Physics, U.S. Department of Energy under Award No. DE-FG02-96ER40983 (UTK) and DEAC05-00OR22725 (ORNL), and by the National Nuclear Security Administration under the Stewardship Science Academic Alliances program through DOE Award No. DENA0002132. This work was supported by National Science Foundation under Grants No. PHY-1430152 (JINA Center for the Evolution of the Elements), No. PHY-1565546 (NSCL), and No. PHY-1714153 (Central Michigan Uni…

Low-diffusion Xe-He gas mixtures for rare-event detection: electroluminescence yield

2020

[EN] High pressure xenon Time Projection Chambers (TPC) based on secondary scintillation (electroluminescence) signal amplification are being proposed for rare event detection such as directional dark matter, double electron capture and double beta decay detection. The discrimination of the rare event through the topological signature of primary ionisation trails is a major asset for this type of TPC when compared to single liquid or double-phase TPCs, limited mainly by the high electron diffusion in pure xenon. Helium admixtures with xenon can be an attractive solution to reduce the electron diffu- sion significantly, improving the discrimination efficiency of these optical TPCs. We have m…

Conceptual design of the AGATA 1$\pi$ array at GANIL

2017

The Advanced GAmma Tracking Array (AGATA) has been installed at the GANIL facility, Caen-France. This setup exploits the stable and radioactive heavy-ions beams delivered by the cyclotron accelerator complex of GANIL. Additionally, it benefits from a large palette of ancillary detectors and spectrometers to address in-beam γ-ray spectroscopy of exotic nuclei. The set-up has been designed to couple AGATA with a magnetic spectrometer, charged-particle and neutron detectors, scintillators for the detection of high-energy γ rays and other devices such as a plunger to measure nuclear lifetimes. In this paper, the design and the mechanical characteristics of the set-up are described. Based on sim…

Sensitivity enhancement in pulse EPR distance measurements

2004

Established pulse EPR approaches to the measurement of small dipole-dipole couplings between electron spins rely on constant-time echo experiments to separate relaxational contributions from dipolar time evolution. This requires a compromise between sensitivity and resolution to be made prior to the measurement, so that optimum data are only obtained if the magnitude of the dipole-dipole coupling is known beforehand to a good approximation. Moreover, the whole dipolar evolution function is measured with relatively low sensitivity. These problems are overcome by a variable-time experiment that achieves suppression of the relaxation contribution by reference deconvolution. Theoretical and exp…

Electron Ion Collider: The Next QCD Frontier: Understanding the glue that binds us all

2016

International audience; This White Paper presents the science case of an Electron-Ion Collider (EIC), focused on the structure and interactions of gluon-dominated matter, with the intent to articulate it to the broader nuclear science community. It was commissioned by the managements of Brookhaven National Laboratory (BNL) and Thomas Jefferson National Accelerator Facility (JLab) with the objective of presenting a summary of scientific opportunities and goals of the EIC as a follow-up to the 2007 NSAC Long Range plan. This document is a culmination of a community-wide effort in nuclear science following a series of workshops on EIC physics over the past decades and, in particular, the focus…