scholarly journals η-nuclei in the SCAN experiment

2019 ◽  
Vol 204 ◽  
pp. 09001
Author(s):  
Katarína Michaličková ◽  
S.V. Afanasiev ◽  
D.K. Dryablov ◽  
S. Vokál
Keyword(s):  
Energy Spectrum ◽  
Strong Interaction ◽  
Time Resolution ◽  
Beam Energy ◽  
Neutron Detector ◽  
Minimum Energy ◽  
Interaction Force ◽  
Experimental Setup ◽  
Internal Target ◽  
Resonance Formation

η-mesic nucleus or the quasibound nuclear state of an η-meson in a nucleus is caused by the strong-interaction force alone. The project SCAN2 is aimed at searching and studying the η-meson nuclei production. The experiment is based on two-arms spectrometer using internal target at the Nuclotron. The setup was designed to study products from η-meson nucleus decay in the reaction d + 12C → (A)η + X → π + p + (A – 2) at deuteron energies from 0:5 to 2:5 GeV/nucl. The energy spectrum of secondary protons has been measured. The dependence of the yields of protons and pions on the beam energy has been obtained. This dependence can show us the minimum energy for the S 11 resonance formation. The first prototype of the neutron detector, which will be used in a new modified experimental setup SCAN3 for recording of neutrons from η-nucleus decays in the πn and pn channels, has been tested. The time-offlight method to obtain the neutron spectrum was used. The time resolution and efficiency of the neutron detector have been obtained.

New layout of time resolved beam energy spectrum measurement for Dragon-I

2010 ◽  
Vol 22 (3) ◽  
pp. 639-641
Author(s):  
廖树清 Liao Shuqing ◽  
张开志 Zhang Kaizhi ◽  
石金水 Shi Jinshui
Keyword(s):  
Energy Spectrum ◽  
Beam Energy ◽  
Time Resolved ◽  
Spectrum Measurement

The lines-of-force landscape of interactions between molecules in crystals; cohesive versus tolerant and `collateral damage' contact

2010 ◽  
Vol 66 (3) ◽  
pp. 396-406 ◽  
Author(s):  
Angelo Gavezzotti
Keyword(s):  
Crystal Structures ◽  
Structure Prediction ◽  
Crystal Packing ◽  
Minimum Energy ◽  
Lattice Energy ◽  
Interaction Force ◽  
Coordination Shell ◽  
Geometrical Parameters ◽  
Interaction Energies ◽  
Organic Salts

A quantitative analysis of relative stabilities in organic crystal structures is possible by means of reliable calculations of interaction energies between pairs of molecules. Such calculations have been performed by the PIXEL method for 1108 non-ionic and 98 ionic organic crystals, yielding total energies and separate Coulombic polarization and dispersive contributions. A classification of molecule–molecule interactions emerges based on pair energy and its first derivative, the interaction force, which is estimated here explicitly along an approximate stretching path. When molecular separation is not at the minimum-energy value, as frequently happens, forces may be attractive or repulsive. This information provides a fine structural fingerprint and may be relevant to the mechanical properties of materials. The calculations show that the first coordination shell includes destabilizing contacts in ∼ 9% of crystal structures for compounds with highly polar chemical groups (e.g. CN, NO2, SO2). Calculations also show many pair contacts with weakly stabilizing (neutral) energies; such fine modulation is presumably what makes crystal structure prediction so difficult. Ionic organic salts or zwitterions, including small peptides, show a Madelung-mode pairing of opposite ions where the total lattice energy is stabilized from sums of strongly repulsive and strongly attractive interactions. No obvious relationships between atom–atom distances and interaction energies emerge, so analyses of crystal packing in terms of geometrical parameters alone should be conducted with due care.

scholarly journals A new experimental setup for high-throughput controlled non-photochemical laser-induced nucleation: application to glycine crystallization

2014 ◽  
Vol 47 (4) ◽  
pp. 1252-1260 ◽  
Author(s):  
Bertrand Clair ◽  
Aziza Ikni ◽  
Wenjing Li ◽  
Philippe Scouflaire ◽  
Vincent Quemener ◽  
...  
Keyword(s):  
Energy Density ◽  
Laser Beam ◽  
High Throughput ◽  
Beam Energy ◽  
Laser Beams ◽  
Experimental Setup ◽  
Field Of Study ◽  
Technical Description ◽  
Beam Energy Density

Non-photochemical laser-induced nucleation (NPLIN) has been a growing field of study since 1996, and more than 40 compounds including organics, inorganics and proteins have now been probed under various conditions (solvents, laser types, laser beamsetc.). The potential advantages of using this technique are significant, in particular polymorphic control. To realize these benefits, the objective is a carefully designed experimental setup and highly controlled parameters, for example temperature and energy density, in order to reduce the uncertainty regarding the origin of nucleation. In this paper, a new experimental setup designed to study NPLIN is reported. After a full technical description of the present setup, the different functionalities of this device will be illustrated through results on glycine. Glycine crystals obtained through NPLIN nucleate at the meniscus and exhibit different morphologies. The nucleation efficiency, as a function of the supersaturation of the solution used and the laser beam energy density, has also been established for a large number of samples, with all other parameters held constant.

Measurement of beam energy spectrum and impurity content in high‐power neutral beam injectors

1985 ◽  
Vol 3 (3) ◽  
pp. 1085-1088 ◽  
Author(s):  
R. A. Langley ◽  
P. M. Ryan ◽  
C. C. Tsai ◽  
M. M. Menon ◽  
E. M. Botnick ◽  
...  
Keyword(s):  
Energy Spectrum ◽  
High Power ◽  
Beam Energy ◽  
Impurity Content ◽  
Neutral Beam ◽  
Neutral Beam Injectors

The conceptual design of 1-ps time resolution neutron detector for fusion reaction history measurement at OMEGA and the National Ignition Facility

2020 ◽  
Vol 91 (6) ◽  
pp. 063304
Author(s):  
Yasunobu Arikawa ◽  
Masato Ota ◽  
Makoto Nakajima ◽  
Tomoki Shimizu ◽  
Sadashi Segawa ◽  
...  
Keyword(s):  
Conceptual Design ◽  
Time Resolution ◽  
Neutron Detector ◽  
Fusion Reaction ◽  
National Ignition Facility

scholarly journals Crab Pulsar: Enhanced Optical Emission During Giant Radio Pulses

2011 ◽  
Vol 7 (S285) ◽  
pp. 296-298
Author(s):  
Susan Collins ◽  
Andy Shearer ◽  
Ben Stappers ◽  
Cesare Barbieri ◽  
Giampiero Naletto ◽  
...  
Keyword(s):  
Energy Spectrum ◽  
Time Resolution ◽  
Optical Emission ◽  
High Time ◽  
High Time Resolution ◽  
Crab Pulsar ◽  
Comprehensive Model ◽  
Optical Pulses ◽  
Pulsar Emission ◽  
Optical Wavelengths

AbstractAlthough optical pulsar studies have been limited to a few favoured objects, the observation of pulsars at optical wavelengths provides an opportunity to derive a number of important pulsar characteristics, including the energy spectrum of the emitting electrons and the geometry of the emission zone. These parameters will be vital for a comprehensive model of pulsar emission mechanisms. Observations of the Crab pulsar with the high-time-resolution photon-tagging photometer IquEYE show an optical–radio delay of ~178 μs. Incorporating simultaneous Jodrell Bank radio observations suggested a correlation between giant radio pulses and enhanced optical pulses for this pulsar, thus offering possible evidence for the reprocessing of radio photons.

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