scholarly journals Lifetime Measurements at NCSR “Demokritos”

2020 ◽  
Vol 19 ◽  
pp. 41
Author(s):  
S. F. Ashley ◽  
M. Axiotis ◽  
V. Foteinou ◽  
S. Harrisopulos ◽  
T. Konstantinopoulos ◽  
...  
Keyword(s):  
Excited States ◽  
Proton Scattering ◽  
Lifetime Measurements ◽  
Values Development ◽  
Hpge Detectors ◽  
Doppler Shift Attenuation ◽  
Inelastic Proton Scattering ◽  
Γ Rays ◽  
Set Up ◽  
Good Agreement

Proof-of-principle inelastic proton scattering measurements have been performed at NCSR “Demokritos”. Excited states in 64Zn and 92Mo were populated using the (p,p'γ) reaction with E(p) = 7 MeV. The reaction γ rays were detected using four HPGe detectors at eight separate angles, with respect to the beam-axis. From Doppler-shift attenuation of the ∞ rays, lifetimes for eight excited states in 64Zn and for the Iπ = 2^+_2 and 2^+_3 states in 92Mo were deduced. The lifetimes measured in 92Mo are in good agreement with adopted values whereas the lifetimes measured in 64Zn are typically longer than the literature values. Development of the experimental set-up and potential novel physics cases where this reaction could be used are briefly discussed.

Properties of the 4.038 MeV state in 25Al

1968 ◽  
Vol 46 (24) ◽  
pp. 2789-2796 ◽  
Author(s):  
H. Röpke ◽  
N. Anyas-Weiss ◽  
A. E. Litherland
Keyword(s):  
Decay Scheme ◽  
Previous Measurement ◽  
Proton Scattering ◽  
Parity Assignment ◽  
Attenuation Measurement ◽  
Mixing Ratios ◽  
Doppler Shift Attenuation ◽  
Inelastic Proton Scattering ◽  
Γ Rays ◽  
Γ Ray

The 4.038 MeV state in 25Al, which is also the Ep = 1.824 MeV resonance in the 24Mg(p,γ) reaction, has been investigated using the 24Mg(p,y) reaction. The γ-ray decay scheme is given and a limit of [Formula: see text], is obtained for the inelastic proton scattering width. Angular distribution measurements of deexcitation γ rays confirm previous values of radiation mixing ratios, but cannot remove the Jπ = 9/2+, 5/2+ ambiguity in the spin–parity assignment. A Doppler shift attenuation measurement of the4.038 MeV deexcitation γ ray yields ƒ(τ) = 0.91 ± 0.02, corresponding to a lifetime of τ(4.038) = 22 ± 6 fs. The particle widths are derived using the lifetime and a previous measurement of the γ-ray yield at the 24Mg, Ep = 1.824 MeV resonance. On the basis of the particle width, arguments are given for a Jπ = 9/2+ assignment to the 4.038 MeV state.

scholarly journals Symmetries in mirror nuclei 31S and 31P

2018 ◽  
Vol 194 ◽  
pp. 03001
Author(s):  
D. Tonev ◽  
G. de Angelis ◽  
N. Goutev ◽  
S. Iliev ◽  
R. Orlandi ◽  
...  
Keyword(s):  
Charged Particle ◽  
Excited States ◽  
Doppler Shift ◽  
Isospin Symmetry ◽  
Particle Detector ◽  
Lifetime Measurements ◽  
Angular Correlations ◽  
Doppler Shift Attenuation ◽  
First Time

Excited states in mirror nuclei 31S and 31P were populated in the 1n and 1p exit channels, respectively, of the reaction 20Ne + 12C. The beam of 20Ne, with an energy of 33 MeV, was delivered for the first time by the Piave-Alpi accelerator of the Laboratori Nazionali di Legnaro. Angular correlations of coincident pairs and Doppler-shift attenuation lifetime measurements in 31S and 31P were performed using the multidetector array GASP in conjunction with the EUCLIDES charged particle detector. A comparison of the determined B(E1) strengths of the analog mirror 7/2- → 5/2+ transitions indicates the presence of a violation of isospin symmetry.

The character of excited states in 41Sc studied by elastic and inelastic proton scattering from 40Ca

1970 ◽  
Vol 145 (2) ◽  
pp. 534-548 ◽  
Author(s):  
A. Marinov ◽  
Ch. Drory ◽  
E. Navon ◽  
J. Burde ◽  
G. Engler
Keyword(s):  
Excited States ◽  
Proton Scattering ◽  
Inelastic Proton Scattering

An examination of Doppler shift attenuation factors and lifetimes for excited nuclear states in 59Cu and 63Cu

1980 ◽  
Vol 58 (3) ◽  
pp. 359-362 ◽  
Author(s):  
B. E. Cooke ◽  
J. R. Leslie ◽  
W. McLatchie ◽  
P. Skensved
Keyword(s):  
Energy Loss ◽  
Excited States ◽  
Doppler Shift ◽  
Speed Of Light ◽  
Proton Capture ◽  
Doppler Shift Attenuation ◽  
Resonance Strengths ◽  
Γ Rays ◽  
Standard Energy ◽  
Existing Data

Excited states in 59Cu and 63Cu have been studied with radiative proton capture. Doppler shift attenuation factors have been measured for γ-rays depopulating these states, with ion recoil speeds of approximately 0.1% of the speed of light. Measurements of resonance strengths reported here, together with existing data from other techniques, have been used to deduce lifetimes for the same states. For five cases where the DSA factors and the lifetimes have been determined independently, consistency with DSAM theory is optimized when the standard energy loss value is multiplied by a factor of 0.94 ± 0.11.

LIFETIME MEASUREMENTS OF EXCITED STATES IN 73As

2004 ◽  
Vol 13 (05) ◽  
pp. 1019-1034 ◽  
Author(s):  
K. P. SINGH ◽  
T. KAKAVAND ◽  
M. HAJIVALIEI
Keyword(s):  
Statistical Theory ◽  
Excited States ◽  
Doppler Shift ◽  
Nuclear Reactions ◽  
Angular Distributions ◽  
Excitation Energies ◽  
Lifetime Measurements ◽  
Mixing Ratios ◽  
Doppler Shift Attenuation ◽  
First Time

The excited states of 73 As have been investigated via the 73 Ge ( p , n γ)73 As reaction with proton beam energies from 2.5–4.3 MeV. The lifetimes of the levels at 769.6, 860.5, 1177.8, 1188.7, 1274.9, 1344.1, 1557.1 and 1975.2 keV excitation energies have been measured for the first time using the Doppler shift attenuation method. The angular distributions have been used to assign the spins and the multipole mixing ratios using statistical theory for compound nuclear reactions. The ambiguity in the spin values for the various levels has been removed. The multipole mixing ratios for eight γ-transitions have been newly measured.

scholarly journals Lifetime measurements in 105Sn: the puzzle of B(E2) strengths in Sn isotopes

2019 ◽  
Vol 223 ◽  
pp. 01048
Author(s):  
Giorgia Pasqualato ◽  
Andrea Gottardo ◽  
Alain Goasduff ◽  
Josè Javier Valiente Dobón ◽  
Daniele Mengoni
Keyword(s):  
Excited States ◽  
Experimental Technique ◽  
Systematic Study ◽  
Doppler Shift ◽  
Isotopic Chain ◽  
Lifetime Measurements ◽  
Preliminary Results ◽  
Shell Closures ◽  
Recoil Distance ◽  
Good Agreement

One of the most studied case to explore the evolution of shell closures far from stability is the doubly-magic and self-conjugated 100Sn nucleus. Information on its doubly-magic nature can be extracted fromthe systematic study of the tin isotopic chain. In this context, the lifetimes of the neutron deficient 105Sn have been investigated with the coincidence Recoil Distance Doppler Shift (RDDS) technique throughthe reaction 50Cr(58Ni,2pn)105Sn. Preliminary results concerning the lifetimesof 105In excited states are in good agreement with the adopted lifetimes, demonstrating the feasibility to extract lifetimes with this experimental technique.

scholarly journals Laboratory Measurements of Light Scattering by Dust Particles

1996 ◽  
Vol 150 ◽  
pp. 409-413
Author(s):  
Patrick P. Combet ◽  
Philippe L. Lamy
Keyword(s):  
Light Scattering ◽  
Laser Beam ◽  
Mie Theory ◽  
Spherical Particles ◽  
Dust Particles ◽  
Laboratory Measurements ◽  
Scattering Function ◽  
Hene Laser ◽  
Set Up ◽  
Good Agreement

AbstractWe have set up an experimental device to optically study the scattering properties of dust particles. Measurements over the 8 — 174° interval of scattering angles are performed on a continuously flowing dust loaded jet illuminated by a polarized red HeNe laser beam. The scattering is averaged over the population of the dust particles in the jet, which can be determined independently, and give the “volume scattering function” for the two directions of polarization directly. While results for spherical particles are in good agreement with Mie theory, those for arbitrary particles show conspicuous deviations.

The Reduction of Bias Error in Transfer Function Estimates Using FFT-Based Analyzers

1984 ◽  
Vol 106 (1) ◽  
pp. 29-35 ◽  
Author(s):  
P. Cawley
Keyword(s):  
Transfer Function ◽  
Random Excitation ◽  
Analogue Computer ◽  
Bias Error ◽  
Testing Time ◽  
Theoretical Predictions ◽  
Set Up ◽  
Modal Mass ◽  
Time Required ◽  
Good Agreement

The susceptibility to bias error of two methods for computing transfer (frequency response) functions from spectra produced by FFT-based analyzers using random excitation has been investigated. Results from tests with an FFT analyzer on a single degree-of-freedom system set up on an analogue computer show good agreement with the theoretical predictions. It has been shown that, around resonance, the bias error in the transfer function estimate H2 (Syy/Sxy*) is considerably less than that in the more commonly used estimate, H1 (Sxy/Sxx). The record length, and hence the testing time, required for a given accuracy is reduced by over 50 percent if the H2 calculation procedure is used. The analysis has also shown that if shaker excitation is used on lightly damped structures with low modal mass, it is important to minimize the mass of the force gage and the moving element of the shaker.

Lifetime measurements of excited states in 115In

1967 ◽  
Vol 96 (1) ◽  
pp. 173-176 ◽  
Author(s):  
T.D. Nainan ◽  
K.D. Clausen ◽  
R.L. Kahle
Keyword(s):  
Excited States ◽  
Lifetime Measurements
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