Application of the differential decay-curve method to γ–γ fast-timing lifetime measurements

2016 ◽  
Vol 833 ◽  
pp. 45-48 ◽  
Author(s):  
P. Petkov ◽  
J.-M. Régis ◽  
A. Dewald ◽  
S. Kisyov
Keyword(s):  
Decay Curve ◽  
Lifetime Measurements ◽  
Fast Timing ◽  
Curve Method

scholarly journals 128Xe: Test for E(5) Symmetry through DDCM and GOSIA Analysis

2019 ◽  
Vol 18 ◽  
pp. 7
Author(s):  
T. Konstantinopoulos ◽  
... Et al.
Keyword(s):  
Excited States ◽  
Inverse Kinematics ◽  
Decay Curve ◽  
Computer Code ◽  
The Novel ◽  
Matrix Elements ◽  
Accelerator Facility ◽  
Lifetime Measurements ◽  
Curve Method ◽  
Γ Ray

Lifetime measurements in 128Xe have been undertaken at the JYFL accelerator facility using the novel Coulex-plunger in inverse kinematics technique [1], [2]. Excited states in 128Xe were populated by the natFe(128Xe, 128Xe*) reaction at E(128Xe)=525 MeV and the subsequent de-excitations were detected in the JUROGAM γ-ray array. Two independent analyses of the data were performed. Firstly the Differential Decay Curve Method (DDCM) [3] was applied to determine lifetimes of the excited states. Secondly, matrix elements and their corresponding B(E2) values, were extracted using the computer code GOSIA [4]. The results are presented and compared with the adopted values. Also, B(E2) values obtained from this work are compared to the values predicted by the E(5) critical-point symmetry, since 128Xe has been proposed as a candidate for E(5) symmetry [5].

scholarly journals Lifetime measurements of yrast states in $$^{\mathbf {178}}$$Pt using the charge plunger method with a recoil separator

2021 ◽  
Vol 57 (4) ◽  
Author(s):  
J. Heery ◽  
L. Barber ◽  
J. Vilhena ◽  
B. S. Nara Singh ◽  
R.-D. Herzberg ◽  
...  
Keyword(s):  
Focal Plane ◽  
Decay Curve ◽  
Alpha Decay ◽  
Alternative Analysis ◽  
Lifetime Measurements ◽  
Lifetime Value ◽  
Charge State Distributions ◽  
Curve Method ◽  
Internal Electron ◽  
Bateman Equation

AbstractLifetime measurements in $$^{178}$$ 178 Pt with excited states de-exciting through $$\gamma $$ γ -ray transitions and internal electron conversions have been performed. Ionic charges were selected by the in-flight mass separator MARA and measured at the focal plane in coincidence with the $$4_1^+\rightarrow 2_1^+$$ 4 1 + → 2 1 + $$257\,$$ 257 keV $$\gamma $$ γ -ray transition detected using the JUROGAM 3 spectrometer. The resulting charge-state distributions were analysed using the differential decay curve method (DDCM) framework to obtain a lifetime value of 430(20) ps for the $$2_1^+$$ 2 1 + state. This work builds on a method that combines the charge plunger technique with the DDCM analysis. As an alternative analysis, ions were selected in coincidence with the $$^{178}$$ 178 Pt alpha decay ($$E_{\mathrm {alpha}} = 5.458(5)$$ E alpha = 5.458 ( 5 ) MeV) at the focal plane. Lifetime information was obtained by fitting a two-state Bateman equation to the decay curve with the lifetime of individual states defined by a single quadrupole moment. This yielded a lifetime value of 430(50) ps for the $$2_1^+$$ 2 1 + state, and 54(6) ps for the $$4_1^+$$ 4 1 + state. An analysis method based around the Bateman equation will become especially important when using the charge plunger method for the cases where utilising coincidences between prompt $$\gamma $$ γ rays and recoils is not feasible.

scholarly journals Fast-timing lifetime measurements of excited states inCu67

2014 ◽  
Vol 89 (6) ◽  
Author(s):  
C. R. Niţă ◽  
D. Bucurescu ◽  
N. Mărginean ◽  
M. Avrigeanu ◽  
G. Bocchi ◽  
...  
Keyword(s):  
Excited States ◽  
Lifetime Measurements ◽  
Fast Timing

Beam-foil lifetime measurements in Pb III and Pb IV

1988 ◽  
Vol 66 (5) ◽  
pp. 402-404 ◽  
Author(s):  
W. Ansbacher ◽  
E. H. Pinnington ◽  
J. A. Kernahan
Keyword(s):  
Wavelength Range ◽  
Decay Curve ◽  
Polarization Model ◽  
Lifetime Measurements ◽  
Recent Calculation ◽  
Core Correlation ◽  
Intensity Decay ◽  
Beam Foil ◽  
Good Agreement

Beam-foil intensity decay curves for transitions in the wavelength range from 900 to 2200 Å are used to derive the lifetimes of the 6s6p1P1 and 3P1 6s6d1D2, 6s7s1S0, and 6p21D2 levels of Pb III, and the 6p2P1/2 and 2P3/2, 6d2D3/2 and 2D5/2, 7s2S1/2, and 5d96s22D3/2 levels of Pb IV, arbitrarily normalized decay curve (ANDC) analyses being used for the 6s6p and 6p levels. In the case of the two 6s6p levels studied in Pb III, good agreement is found with a recent calculation in which a polarization model accounts for valence–core correlation. However, the agreement between the lifetimes observed for the 6p levels in Pb IV and a similar, earlier calculation is only fair.

scholarly journals Lifetimes and electromagnetic transition strength in 124Ba

2018 ◽  
Vol 194 ◽  
pp. 03004
Author(s):  
Mariya Trichkova ◽  
Marcel Beckers ◽  
Kalin Gladnishki ◽  
Alfred Dewald ◽  
Andrey Blazhev ◽  
...  
Keyword(s):  
Excited States ◽  
Doppler Shift ◽  
Structural Changes ◽  
Decay Curve ◽  
Transition Strength ◽  
Electromagnetic Transition ◽  
Coincidence Data ◽  
Curve Method ◽  
Recoil Distance ◽  
Γ Ray

Lifetimes of excited states of 124Ba were measured by the Recoil Distance Doppler Shift (RDDS) technique. The γ-ray coincidence data were analysed by the Differential Decay Curve method (DDCM). The trend of the experimentally deduced normalized B(E2) values reveals a drop at the 8+1 state, which may be caused by structural changes in the backbending region.

Lifetime Measurements of Several S, P, and D States of Thallium in a Glow Discharge by Single-Step and Two-Step Laser-Excited Fluorescence

2008 ◽  
Vol 62 (1) ◽  
pp. 78-85 ◽  
Author(s):  
N. Taylor ◽  
N. Omenetto ◽  
B. W. Smith ◽  
J. D. Winefordner
Keyword(s):  
Glow Discharge ◽  
Laser Pulse ◽  
Metastable State ◽  
Decay Curve ◽  
Single Step ◽  
Metastable Level ◽  
Applied Current ◽  
Lifetime Measurements ◽  
Time Resolved ◽  
Current Dependence

The lifetimes of several states in a thallium see-through hollow cathode discharge, or galvatron, are obtained to characterize its potential as an atomic line filter. The lifetimes of the thallium 6 2D3/2, 6 2D5/2, and 7 2S1/2 states are measured by time-resolved single-step laser-excited fluorescence by use of a 276.787 nm laser pulse or a 535.046 nm laser pulse and measuring the resulting fluorescence waveform at the appropriate wavelength. Values of 6.4 ± 0.1, 7.5 ± 1.1, and 7.7 ± 0.2 ns were obtained for the 6 2D3/2, 6 2D5/2, and 7 2S1/2 states, respectively, which agree with values obtained by previous authors, as well as calculated values. No current dependence was observed for each of these states. The lifetime of the long-lived thallium 6 2P3/2° metastable state was measured by two-step laser-excited fluorescence at various applied currents. The metastable level was pumped by a 276.787 nm laser pulse, and a temporally delayed 535.046 nm laser pulse interrogated the population of the metastable state. Relating the fluorescence intensity to the population of the metastable state as a function of delay time yielded a decay curve for the 6 2P3/2° metastable state. Values of 2.1 ± 0.2, 2.8 ± 0.1, 3.1 ± 0.3, 3.8 ± 0.4, and 4.8 ± 0.6 μs were found for applied currents of 14.0, 12.0, 10.0, 8.0, and 6.0 mA, respectively. The resulting lifetimes for the 6 2P3/2° metastable state clearly show a dependence on the applied current and are expected to be due to collisions with the wall of the cathode, as well as a contribution due to collisions with electrons.

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