RAP — ACOUSTIC DETECTION OF PARTICLES: FIRST RESULTS AT 4.2 K

2005 ◽  
Vol 20 (29) ◽  
pp. 7054-7056
Author(s):  
C. LIGI ◽  
M. BASSAN ◽  
S. BERTOLUCCI ◽  
B. BUONOMO ◽  
E. COCCIA ◽  
...  
Keyword(s):  
Cryogenic Temperature ◽  
Dilution Refrigerator ◽  
Test Facility ◽  
Acoustic Detection ◽  
Beam Test ◽  
Mechanical Vibrations ◽  
First Results ◽  
Different Temperatures ◽  
First Time ◽  
Good Agreement

RAP (Rivelazione Acustica di Particelle) is a small cylindrical aluminum bar (l = 500 mm , d = 181.7 mm ) placed at the DAΦNE Beam Test Facility, where it is hit by a 510 MeV electron beam, coming from the DAΦNE Linac. Aim of the experiment is to measure the mechanical vibrations of the bar caused by the interaction with the beam. On June, 2004 RAP successfully collected data for the first time at cryogenic temperature. Several runs at different temperatures (4.5, 70 and 273 K) have been performed and a number of shots in normal-conducting state of the bar were detected. The preliminary results are in good agreement with the Thermo-Acoustic Model. In the next months the mounting of a dilution refrigerator and the data taking of the bar in the superconducting state (T = 100 mK ) have been planned.

First results of the ITER-relevant negative ion beam test facility ELISE (invited)

2014 ◽  
Vol 85 (2) ◽  
pp. 02B305 ◽  
Author(s):  
U. Fantz ◽  
P. Franzen ◽  
B. Heinemann ◽  
D. Wünderlich
Keyword(s):  
Ion Beam ◽  
Negative Ion ◽  
Test Facility ◽  
Beam Test ◽  
First Results

scholarly journals Commissioning and first results of the ITER-relevant negative ion beam test facility ELISE

2013 ◽  
Vol 88 (12) ◽  
pp. 3132-3140 ◽  
Author(s):  
P. Franzen ◽  
B. Heinemann ◽  
U. Fantz ◽  
D. Wünderlich ◽  
W. Kraus ◽  
...  
Keyword(s):  
Ion Beam ◽  
Negative Ion ◽  
Test Facility ◽  
Beam Test ◽  
First Results

Temperature Dependent Optical Response of Si(100): Theory vs. Experiment

2011 ◽  
Vol 1370 ◽  
Author(s):  
A.I. Shkrebtii ◽  
J. Heron ◽  
J.L. Cabellos ◽  
N. Witkowski ◽  
O. Pluchery ◽  
...  
Keyword(s):  
Optical Response ◽  
Layer By Layer ◽  
Temperature Dependent ◽  
Reflectance Anisotropy ◽  
Surface Optical ◽  
Wide Range ◽  
Different Temperatures ◽  
Linear Optical Properties ◽  
First Time ◽  
Good Agreement

ABSTRACTWe investigate theoretically and experimentally the temperature-dependent linear optical properties of the clean c(4×2) reconstructed Si(100) surface for a wide range of temperatures. We combine two theoretical formalisms: the first one incorporates the contribution of temperature-dependent atomic motion to the surface optical response and, the second uses a dielectric function layer-by-layer separation method. Using these formalisms, we model temperature-dependent reflectance anisotropy (RA) of this surface for the first time: finite temperature ab-initio Car-Parrinello Molecular Dynamics (CPMD) at different temperatures up to 1000 K provide temperature-dependent atomic structural inputs for optical calculations and subsequent average of dielectric functions. Experimentally, one-domain c(4x2) Si(100) surface was prepared and characterised by Reflectance Anisotropy Spectroscopy (RAS) in a temperature range between 300 K and 800 K. Good agreement between experiment and theory is demonstrated, including a temperature-induced red shift of both the surface and bulk optical peaks. Theoretical results indicate that the temperature-induced modification of the optical response is substantially more pronounced for the surface than for the bulk.

Ground state molecular parameters of phosphine, PH3, from the simultaneous analysis of the high-resolution infrared, microwave and submillimeterwave spectra

1985 ◽  
Vol 50 (11) ◽  
pp. 2480-2492 ◽  
Author(s):  
Soňa Přádná ◽  
Dušan Papoušek ◽  
Jyrki Kauppinen ◽  
Sergei P. Belov ◽  
Andrei F. Krupnov ◽  
...  
Keyword(s):  
Fourier Transform ◽  
High Resolution ◽  
Ground State ◽  
Unitary Transformation ◽  
Point Of View ◽  
Acoustic Detection ◽  
Molecular Parameters ◽  
Microwave Spectrometer ◽  
Fourier Transform Spectra ◽  
First Time

Fourier transform spectra of the ν2 band of PH3 have been remeasured with 0.0045 cm-1 resolution. Ground state combination differences from these data have been fitted simultaneously with the microwave and submillimeterwave data to determine the ground state spectroscopical parameters of PH3 including the parameters of the Δk = ± 3n interactions. The correlation between the latter parameters has been discussed from the point of view of the existence of two equivalent effective rotational operators which are related by a unitary transformation. The ΔJ = 0, +1, ΔK = 0 (A1 ↔ A2, E ↔ E) rotational transitions in the ν2 and ν4 states have been measured for the first time by using a microwave spectrometer and a radiofrequency spectrometer with acoustic detection.

Multicanonical Molecular Dynamics Simulation Study of the Liquid-Solid and Solid-Solid Transitions in Lennard-Jones Clusters

2011 ◽  
Author(s):  
Toshihiro Kaneko ◽  
Kenji Yasuoka ◽  
Ayori Mitsutake ◽  
Xiao Cheng Zeng
Keyword(s):  
Molecular Dynamics ◽  
Heat Capacity ◽  
Transition Temperature ◽  
Peak Position ◽  
Temperature Curve ◽  
Dynamics Simulation ◽  
Lennard Jones ◽  
Dynamics Simulations ◽  
First Time ◽  
Good Agreement

Multicanonical molecular dynamics simulations are applied, for the first time, to study the liquid-solid and solid-solid transitions in Lennard-Jones (LJ) clusters. The transition temperatures are estimated based on the peak position in the heat capacity versus temperature curve. For LJ31, LJ58 and LJ98, our results on the solid-solid transition temperature are in good agreement with previous ones. For LJ309, the predicted liquid-solid transition temperature is also in agreement with previous result.

scholarly journals AGN Spectra as Seen by the Infrared Space Observatory: First Results

1997 ◽  
Vol 159 ◽  
pp. 333-336
Author(s):  
D. Lutz ◽  
R. Genzel ◽  
E. Sturm ◽  
A.F.M. Moorwood ◽  
E. Oliva ◽  
...  
Keyword(s):  
Fine Structure ◽  
Short Wavelength ◽  
Molecular Hydrogen ◽  
Molecular Gas ◽  
Space Observatory ◽  
Infrared Space Observatory ◽  
First Results ◽  
External Galaxies ◽  
First Time ◽  
Fine Structure Lines

AbstractWe discuss 2.5–45 µm spectra of the Circinus galaxy and of Cen A, obtained with the Short Wavelength Spectrometer (SWS) on board the Infrared Space Observatory. The large number of detected ionic fine structure lines, observable also in visually obscured sources, provides strong constraints on the shape of the ionizing spectrum, which is found to exhibit a UV bump peaking at ~ 70 eV in the case of Circinus. Pure rotational emission of molecular hydrogen, directly probing warm molecular gas, can for the first time be detected in external galaxies.

scholarly journals Experimental and Numerical Buckling Analyses of Laminated Composite Plates under Temperature Effects

2010 ◽  
Vol 19 (4) ◽  
pp. 096369351001900 ◽  
Author(s):  
Emin Ergun
Keyword(s):  
Composite Plate ◽  
Numerical Solutions ◽  
Laminated Composite ◽  
Composite Plates ◽  
Buckling Load ◽  
Fibre Reinforcement ◽  
Stacking Sequence ◽  
Laminated Composite Plates ◽  
Different Temperatures ◽  
Good Agreement

The aim of this study is to investigate, experimentally and numerically, the change of critical buckling load in composite plates with different ply numbers, orientation angles, stacking sequences and boundary conditions as a function of temperature. Buckling specimens have been removed from the composite plate with glass-fibre reinforcement at [0°]i and [45°]i (i= number of ply). First, the mechanical properties of the composite material were determined at different temperatures, and after that, buckling experiments were done for those temperatures. Then, numerical solutions were obtained by modelling the specimens used in the experiment in the Ansys10 finite elements package software. The experimental and numerical results are in very good agreement with each other. It was found that the values of the buckling load at [0°] on the composite plates are higher than those of other angles. Besides, symmetrical and anti-symmetrical conditions were examined to see the effect of the stacking sequence on buckling and only numerical solutions were obtained. It is seen that the buckling load reaches the highest value when it is symmetrical in the cross-ply stacking sequence and it is anti-symmetrical in the angle-ply stacking sequence.

Darstellung, Schwingungsspektren und Normalkoordinatenanalyse von Chloro-Bromo-Rhodaten(III) / Preparation, Vibration Spectra and Normal Coordinate Analysis of Chloro-Bromo-Rhodates(III)

1989 ◽  
Vol 44 (10) ◽  
pp. 1221-1227 ◽  
Author(s):  
W. Preetz ◽  
W. Kuhr
Keyword(s):  
Exchange Chromatography ◽  
Trans Isomers ◽  
Normal Coordinate ◽  
Valence Force ◽  
Trans Influence ◽  
Diethylaminoethyl Cellulose ◽  
Point Groups ◽  
First Time ◽  
Ir And Raman ◽  
Good Agreement

The mixed chloro-bromo-rhodates(III) [RhClnBr6-n]3-, n = 1-5, have been separated for the first time by ion exchange chromatography on diethylaminoethyl-cellulose. Due to the stronger trans-effect of Br, as compared with Cl, on treatment of [RhBr6]3- with conc. HCl nearly pure cis/fac-isomers for n = 2, 3, 4 are formed. The reaction of [RhCl6]3- with conc. HBr yields mixtures of the cis/trans-isomers for n = 2, 4, which cannot be separated, but mer-[RhCl3Br3]3 is formed stereospecifically. The IR and Raman spectra of all isolated mixed ligand complexes are completely assigned according to point groups Oh, D3d, C4v, C3v and C2v, supported by normal coordinate analyses based on a general valence force field. The good agreement of calculated and observed frequencies confirms the assignments. Due to the stronger trans-influence of Br as compared to Cl, in all asymmetric Cl—Rh—Br axes the Rh—Br bonds are strengthened and the Rh—Cl bonds are weakened, indicated by valence force constants for Rh—Br approximately 14% higher, for Rh—Cl 10% lower, as compared with the values calculated for symmetric Br—Rh—Br and Cl—Rh—Cl axes, respectively.

Temperature Dependence of Hole Impact Ionization Coefficient in 4H-SiC Photodiodes

2009 ◽  
Vol 615-617 ◽  
pp. 311-314 ◽  
Author(s):  
W.S. Loh ◽  
J.P.R. David ◽  
B.K. Ng ◽  
Stanislav I. Soloviev ◽  
Peter M. Sandvik ◽  
...  
Keyword(s):  
Phonon Scattering ◽  
Impact Ionization ◽  
Positive Temperature Coefficient ◽  
Positive Temperature ◽  
Different Temperatures ◽  
Ionization Coefficients ◽  
Increasing Temperature ◽  
The Impact ◽  
Good Agreement ◽  
Ionization Rates

Hole initiated multiplication characteristics of 4H-SiC Separate Absorption and Multiplication Avalanche Photodiodes (SAM-APDs) with a n- multiplication layer of 2.7 µm were obtained using 325nm excitation at temperatures ranging from 300 to 450K. The breakdown voltages increased by 200mV/K over the investigated temperature range, which indicates a positive temperature coefficient. Local ionization coefficients, including the extracted temperature dependencies, were derived in the form of the Chynoweth expression and were used to predict the hole multiplication characteristics at different temperatures. Good agreement was obtained between the measured and the modeled multiplication using these ionization coefficients. The impact ionization coefficients decreased with increasing temperature, corresponding to an increase in breakdown voltage. This result agrees well with the multiplication characteristics and can be attributed to phonon scattering enhanced carrier cooling which has suppressed the ionization process at high temperatures. Hence, a much higher electric field is required to achieve the same ionization rates.

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