Using a clinical linac to determine the energies of gamma-ray transitions and half-lives of barium nuclei

2020 ◽  
Vol 35 (10) ◽  
pp. 2050062
Author(s):  
Abdullah Engin Çalık ◽  
Kaan Manisa ◽  
Ahmet Biçer ◽  
Mehmet Erdoğan ◽  
Mürsel Şen ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Linear Accelerator ◽  
Nuclear Physics ◽  
Hpge Detector ◽  
Gamma Ray ◽  
Energy Levels ◽  
Photonuclear Reactions ◽  
High Purity Germanium ◽  
Physics Experiment ◽  
First Time

Photonuclear reactions have great importance in understanding the structure of the nuclei. These reactions, performed using the gamma rays obtained by way of bremsstrahlung, are a standard nuclear physics experiment. In this study, a non-enriched barium sample was activated for the first time by using a clinical linear accelerator (cLINACs). The spectrum of barium radioisotopes was obtained by using a gamma spectrometry with a high purity germanium (HPGe) detector. The obtained spectroscopic data were analyzed and energy levels and half-life values together with their uncertainties were obtained. Some energy levels and half-lives of [Formula: see text]Ba were determined with more precision than those of literature values.

scholarly journals Determination of the energy transitions and half-lives of Rubidium nuclei

Open Physics ◽  
2018 ◽  
Vol 16 (1) ◽  
pp. 63-68 ◽  
Author(s):  
Ahmet Biçer ◽  
Kaan Manisa ◽  
Abdullah Engin Çalık ◽  
Mehmet Erdoğan ◽  
Mürsel Şen ◽  
...  
Keyword(s):  
Nuclear Physics ◽  
Germanium Detector ◽  
Nuclear Research ◽  
Photonuclear Reactions ◽  
Linear Accelerators ◽  
Efficient Tool ◽  
Transition Energies ◽  
High Purity Germanium ◽  
Physics Experiment

Abstract The photonuclear reactions, first extensively studied in the 1970’s and performed using the gamma rays obtained via bremsstrahlung, are a standard nuclear physics experiment. In this study, a non-enriched Rubidium sample was irradiated with photons produced by a clinical linear electron accelerator (cLINACs) with energies up to 18 MeV with the aim of activating it through photonuclear reactions. The activated sample was measured with a high purity germanium detector (HPGe) with the aim of measuring the transition energies and half-lives. The spectroscopic analysis performed on the obtained data yielded high quality results for the transition energies with precision matching or surpassing the literature data. For the half-lives the results were consistent with the literature, most notably the half-life of 84mRb decay was determined as 20.28(2) m. The results for both energies and half-lives further show that the clinical linear accelerators can be successfully used as an efficient tool in experimental nuclear research endeavors.

High-Purity Germanium Technology for Gamma-Ray and X-Ray Spectroscopy

1993 ◽  
Vol 302 ◽  
Author(s):  
L.S. Darken ◽  
C. E. Cox
Keyword(s):  
Cross Section ◽  
Gamma Rays ◽  
Ground State ◽  
High Purity ◽  
Gamma Ray ◽  
Capture Rate ◽  
X Rays ◽  
Hole Capture ◽  
High Purity Germanium ◽  
Energy Gamma

ABSTRACTHigh-purity germanium (HPGe) for gamma-ray spectroscopy is a mature technology that continues to evolve. Detector size is continually increasing, allowing efficient detection of higher energy gamma rays and improving the count rate and minimum detectable activity for lower energy gamma rays. For low-energy X rays, entrance window thicknesses have been reduced to where they are comparable to those in Si(Li) detectors. While some limits to HPGe technology are set by intrinsic properties, the frontiers have historically been determined by the level of control over extrinsic properties. The point defects responsible for hole trapping are considered in terms of the “standard level” model for hole capture. This model originates in the observation that the magnitude and temperature dependence of the cross section for hole capture at many acceptors in germanium is exactly that obtained if all incident s-wave holes were captured. That is, the capture rate is apparently limited by the arrival rate of holes that can make an angular-momentum-conserving transition to a s ground state. This model can also be generalized to other materials, where it may serve as an upper limit for direct capture into the ground state for either electrons or holes. The capture cross section for standard levels σS.L. is given bywhere g is the degeneracy of the ground state of the center after capture, divided by the degeneracy before capture. Mc is the number of equivalent extrema in the band structure for the carrier being captured, mo is the electronic mass, m* is the effective mass, and T is the temperature in degrees Kelvin.

Gamma-ray production in the 170Er(p,n)170Tm nuclear reaction

Open Physics ◽  
2010 ◽  
Vol 8 (4) ◽  
Author(s):  
Alexandru Mihailescu ◽  
Gheorghe Cata-Danil
Keyword(s):  
High Resolution ◽  
Energy Range ◽  
Nuclear Reaction ◽  
Gamma Rays ◽  
Compound Nucleus ◽  
Beam Energy ◽  
Gamma Ray ◽  
Excitation Functions ◽  
Γ Ray ◽  
First Time

AbstractFor the first time discrete gamma-rays following the nuclear reaction 170Er(p,n)170Tm with enriched target were measured with a high resolution GeHP spectrometer. Protons delivered by the Bucharest FN Tandem Van de Graaff accelerator bombarded a thin self-supporting film of enriched erbium. Measured γ-ray energies (Eγ), their relative intensities (Iγ) and corresponding excitation functions for the beam energy range 2.0–3.6 MeV are reported in the present work. The measured excitation functions were fairly well reproduced by compound nucleus calculations based on the Hauser-Feshbach formalism.

Coulomb excitation of low-energy levels in 45Sc

1979 ◽  
Vol 57 (8) ◽  
pp. 1196-1203 ◽  
Author(s):  
V. U. Patil ◽  
R. G. Kulkarni
Keyword(s):  
Gamma Ray ◽  
Transition Probabilities ◽  
Coulomb Excitation ◽  
Energy Levels ◽  
Negative Parity ◽  
Core Excitation ◽  
Mixing Ratios ◽  
Reduced Transition Probabilities ◽  
Excitation Model ◽  
First Time

Low-lying negative parity levels in 45Sc were Coulomb excited with 2.5 to 3.5 MeV protons and 4 to 5 MeV 4He ions to test the weak coupling core-excitation model. A Ge(Li) detector was used to measure the gamma-ray yields. The 543, 976, 1408, and 1662 keV levels in 45Sc were Coulomb excited for the first time. Gamma-ray angular distributions were measured at 3.0 MeV proton energy in deducing multipole mixing ratios and spin values. Energy level measurements (in units of kiloelectronvolts) and spin values obtained are as follows: 976, 5/2, 7/2 and 1408, 7/2. The E2 and M1 reduced transition probabilities were determined for the six states. The 376, 720, 1237, 1408, and 1662 keV levels have properties consistent with the interpretation of coupling a 1f7/2 proton to the first 2+ core state.

The Decay of 169Yb

1972 ◽  
Vol 50 (19) ◽  
pp. 2348-2354 ◽  
Author(s):  
S. K. Sen ◽  
D. L. Salie ◽  
E. Tomchuk
Keyword(s):  
Direct Measurement ◽  
Gamma Rays ◽  
Internal Conversion ◽  
Gamma Ray ◽  
Conversion Coefficient ◽  
Coulomb Excitation ◽  
Internal Conversion Coefficient ◽  
Electron Capture Decay ◽  
Upper Limits ◽  
First Time

The decay of 169Yb was investigated using several Ge(Li) detectors of different sizes. The following gamma rays (energies in keV and intensities within brackets) were definitely identified with the 169Yb decay: 20.7 (0.66 ± 0.04), 63.1 (124 ± 5), 93.6 (7.2 ± 0.3), 109.8 (50 ± 2), 117.3 (0.08 ± 0.04), 118.2 (5.4 ± 0.2), 130.5 (34 ± 2), 156.7 (0.023 ± 0.004), 177.2(59 ± 3), 198.0 (100), 240.4 (0.33 ± 0.02), 261.0 (4.7 ± 0.2), and 307.7 (28 ± 1). The recently reported weak gamma-ray peaks at 515 (0.008 ± 0.002) and 625 (0.010 ± 0.002) were also observed and could not be ruled out as not belonging to 169Yb. The recently reported gamma-ray peaks at 140, 160, 207, 288, 295, 316, 320, 328, 355, 371, 379, 396, and 417 were detected and shown not to be from the decay of 169Yb while those at 218, 229, 285, 304, 335, 388, 411, and 425 were not observed and upper limits were placed on their intensities. The presence of very weak peaks at 515 and 625 establishes the formation of the 633 keV state of 169Tm following electron capture decay of 169Yb as reported by George. (This level has been previously observed only in Coulomb excitation of 169Tm.) The total internal conversion coefficient for the 20.7 keV transition was determined for the first time from the direct measurement of the gamma-ray intensity as 51 ± 10 corresponding to an M1 transition.

scholarly journals De-excitation Gamma-ray Technique for Improved Resolution in Intermediate Energy Photonuclear Reactions

1996 ◽  
Vol 49 (6) ◽  
pp. 1075 ◽  
Author(s):  
A Kuzin ◽  
R Rassool ◽  
MN Thompson
Keyword(s):  
Gamma Ray ◽  
Intermediate Energy ◽  
Photonuclear Reactions ◽  
State Decay ◽  
Γ Rays ◽  
First Time

Use of residual-state decay γ-rays could be a powerful tool in the study of photonuclear reactions. The practicality of this technique in a tagged-photon experiment is demonstrated for the first time with data on the 12C(γ,p) reaction.

scholarly journals Observational signatures of gamma-rays from bright blazars and wakefield theory

2020 ◽  
Vol 493 (2) ◽  
pp. 2229-2237 ◽  
Author(s):  
N E Canac ◽  
K N Abazajian ◽  
T Tajima ◽  
T Ebisuzaki ◽  
S Horiuchi
Keyword(s):  
Gamma Rays ◽  
Gamma Ray ◽  
Accretion Disc ◽  
Spectral Energy ◽  
Energy Distributions ◽  
Wakefield Acceleration ◽  
Inverse Compton ◽  
Time Variations ◽  
First Time ◽  
Over Time

ABSTRACT Gamma-ray observations have revealed strong variability in blazar luminosities in the gamma-ray band over time-scales as short as minutes. We show, for the first time, that the correlation of the spectrum with intensity is consistent with the behaviour of the luminosity variation of blazar spectral energy distributions (SEDs) along a blazar sequence for low synchrotron peak blazars. We show that the observational signatures of variability with flux are consistent with wakefield acceleration of electrons initiated by instabilities in the blazar accretion disc. This mechanism reproduces the observed time variations as short as 100 s. The wakefield mechanism also predicts a reduction of the electron spectral index with increased gamma-ray luminosity, which could be detected in higher energy observations well above the inverse Compton peak.

Conversion-electron and gamma–gamma directional correlation measurements in 134Ba

1990 ◽  
Vol 68 (12) ◽  
pp. 1479-1485 ◽  
Author(s):  
Bakhshish Chand ◽  
Jatinder Goswamy ◽  
Devinder Mehta ◽  
Nirmal Singh ◽  
P. N. Trehan
Keyword(s):  
Conversion Electron ◽  
Hpge Detector ◽  
Transition Probability ◽  
Energy Levels ◽  
Electron Spectrometer ◽  
Conversion Electrons ◽  
Conversion Coefficients ◽  
First Time ◽  
Rotor Model

Conversion electrons from the decay of 134Cs have been investigated using a mini-orange electron spectrometer. The electron intensities for the K-conversion of 242.7 keV and L, (M + N … ) conversion of 563.2, 795.9, 801.9, 1038.6, 1167.9, and 1365.2 keV transitions in 134Ba are being reported for the first time. The conversion-electron data have been further used to determine the conversion coefficients for various transitions in, 34Ba. Also, the gamma–gamma directional correlation measurements for seven cascades in 134Ba have been carried out using a HPGe–HPGe detector coincidence setup. The multipole admixtures for the 475.3, 563.2, 569.3, 795.9, 801.9, 1038.6, and 1365.2 keV transitions have been deduced from these measurements. A multipole admixture of M1 + 37% E2 has been obtained for the 1038.6 keV transition in 134Ba. The reduced transition probability ratios for the transitions de-exciting second 2+ and 3+ energy levels in 134Ba have been calculated and compared with the values predicted by the triaxial rotor model for γ = 28.5°. This indicates the softness of the, 134Ba nucleus toward γ deformation.

Lifetimes and branching ratios of energy levels of 28Si. II

1969 ◽  
Vol 47 (6) ◽  
pp. 651-656 ◽  
Author(s):  
T. K. Alexander ◽  
C. Broude ◽  
A. J. Ferguson ◽  
J. A. Kuehner ◽  
A. E. LitherLand ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Alpha Particle ◽  
Gamma Ray ◽  
Energy Levels ◽  
Excited Level ◽  
Particle Beam ◽  
High Energy ◽  
Alpha Particles ◽  
Level Information ◽  
Energy Gamma

The gamma rays from the 25Mg(α,nγ)28Si reaction have been studied for alpha-particle energies in the range 6.0 MeV to 7.2 MeV. A 25-cm3 Ge(Li) gamma-ray counter was used to observe the complex high energy gamma-ray spectra at angles between 0° and 130° to the alpha-particle beam. The lifetime ofthe7798-keV level was found to be 0.30 ± 0.10 ps by studying the Doppler broadening of the spectrum lines. The gamma-ray decays of the 8260, 8328, 8411, 8543, and 8587-keV levels were observed. The gamma-ray decays of the 8260 and 8543-keV levels had not been observed previously. The 8260-keV level decays to the first excited level at 1780-keV and the 8543-keV level decays only to the 4617-keV level. Information on the spin-parity combinations of these levels in 28Si was obtained by a measurement of the yield of alpha particles at zero degrees to the beam in the reaction 16O(16O,α)28Si.

THE SIMULATION OF AN IMAGING GAMMA-RAY COMPTON BACKSCATTERING DEVICE USING GEANT4

2014 ◽  
Vol 27 ◽  
pp. 1460152
Author(s):  
D. FLECHAS ◽  
L.G. SARMIENTO ◽  
F. CRISTANCHO ◽  
E. FAJARDO
Keyword(s):  
Gamma Rays ◽  
Nuclear Physics ◽  
Gamma Ray ◽  
Structural Defects ◽  
Compton Camera ◽  
Experimental Conditions ◽  
Imaging Device ◽  
Compton Backscattering ◽  
National University ◽  
Simulated Images

A gamma-backscattering imaging device dubbed Compton Camera, developed at GSI (Darmstadt, Germany) and modified and studied at the Nuclear Physics Group of the National University of Colombia in Bogotá, uses the back-to-back emission of two gamma rays in the positron annihilation to construct a bidimensional image that represents the distribution of matter in the field-of-view of the camera. This imaging capability can be used in a host of different situations, for example, to identify and study deposition and structural defects, and to help locating concealed objects, to name just two cases. In order to increase the understanding of the response of the Compton Camera and, in particular, its image formation process, and to assist in the data analysis, a simulation of the camera was developed using the GEANT4 simulation toolkit. In this work, the images resulting from different experimental conditions are shown. The simulated images and their comparison with the experimental ones already suggest methods to improve the present experimental device

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