Thick target photon yields and angular distributions for the 19F(p,αγ)16O source reaction at incident proton energies between 1.5 and 4.0MeV

Fessler, A.; Massey, T. N.; Micklich, B.J.; Smith, D.L.

doi:10.1016/s0168-9002(00)00303-x

Cited by 22 publications

(15 citation statements)

References 17 publications

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“…Protons are accelerated into a fluorine-containing target to produce γ-rays of 6.13, 6.92, and 7.12 MeV via the 19 F(p,αγ) 16 O reaction [9], [10]. These γ-rays are of sufficient energy to induce fission in fissionable materials, but lie below the energy threshold for photoneutron production in most common materials.…”

Section: A Probing Radiation Sourcementioning

confidence: 99%

Detectors for intense, pulsed active detection

Jackson

Allen

Apruzese

et al. 2010

IEEE Nuclear Science Symposuim &Amp; Medical Imaging Conference

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In intense, pulsed active detection, a single, intense pulse of radiation is used to induce photofission in fissionable material, increasing its detectability. The Mercury pulsed-power generator was converted to positive polarity (+3.7 MV, 325 kA, 50-ns FWHM) to drive an intense, pulsed radiation source based on the FIGARO active detection concept. The probing radiation source consisted of an ion-beam diode and a thick PTFE (Teflon) converter where 6 -7 MeV γ-rays were produced via the 19 F(p,αγ) 16 O reaction. A suite of radiation detectors was used both to detect the presence of irradiated fissionable material and to characterize the probing radiation source. Four types of detectors were used for the source characterization. Thermoluminescent dosimeters were used to measure the angular distribution of the dose associated with x-rays and γ-rays from the ion-beam diode. Plastic scintillator-photodiode detectors were used to characterize the time dependence of this dose. A plastic scintillator-photomultiplier detector was used to monitor the γ-ray intensity of the probing radiation source and to monitor changes in the production of background neutrons by the diode and PTFE converter. A set of rhodium foil activation counters was used to measure the absolute yield of these background neutrons. Two types of detectors with comparable sensitivities were used to measure delayed neutrons resulting from photofission: 3 He proportional counters and a 6 Li-loadedglass-scintillator detector. The neutron detection rate from each detector following the probing radiation pulse was over 100 times higher with depleted uranium present than with lead.

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Section: A Probing Radiation Sourcementioning

confidence: 99%

Detectors for intense, pulsed active detection

Jackson

Allen

Apruzese

et al. 2010

IEEE Nuclear Science Symposuim &Amp; Medical Imaging Conference

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“…Após a fissão desse núcleo em 16 O e uma partícula α, que pode possuir diferentes energias cinéticas, o núcleo residual está em um dos níveis excitados caracterizados pelos spins que aparecem na figura. [28] . .…”

Section: íNdiceunclassified

“…Cada nuclídeo radioativo possui características particulares como tipo de radiação a emitir, a energia de excitação que possui, a energia que a radiação vai carregar e o tempo médio para o decaimento, caracterizado pela meia-vida, que é o intervalo em que o número inicial de átomos se reduz à metade. A figura 2.3 [28] mostra um esquema da reação usada para obter os fótons de 6,128 MeV, após a emissão de uma partícula α pelo 20 Ne, usados em alguns dos nossos trabalhos [63,62,64,89].…”

Section: Produção De Fótons Em Processos Atômicos E Nuclearesunclassified

“…As energias Figura 2.3: Esquema dos níveis de energia do 20 Ne, após a captura de um próton pelo 19 F. Após a fissão desse núcleo em 16 O e uma partícula α, que pode possuir diferentes energias cinéticas, o núcleo residual está em um dos níveis excitados caracterizados pelos spins que aparecem na figura. [28] dos raios-x nos experimentos que realizamos cobriram uma faixa que abrange desde poucos keV até 100 keV. Não há uma divisão energética clara entre raios-x e -γ, que são diferenciados pelo fenômeno que os produziu.…”

Section: Processos De Produção De Fótonsunclassified

“…Na reação 19 F(p, αγ) 16 O, o núcleo composto 20 Ne fissiona emitindo uma partícula alfa, que pode possuir várias energias diferentes, deixando o 16 O a estados excitados, com 6,1, 6,9 ou 7,1 MeV, todos eles decaindo por um gama para o estado fundamental com 100 % de probabilidade, ou no estado com 6,05 MeV que decai por formação interna de pares e + e − [46,24,28] e obrigou ao uso do absorvedor de pósitrons já mencionado. Um espectro simples do HPGe foi obtido com outro detetor, posicionado a 90 o do feixe de prótons.…”

Section: Determinação Experimental Da Intensidade Do Terceiro Escapeunclassified

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Detetores semicondutores de fótons na investigação das interações dos elétrons e fótons com a matéria

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Photon detectors play a central role in the quantification of the interactions of photons and electrons with matter, therefore their characterization is necessary for a wide range of experiments and applications. Accurate determination of the efficiency and response of these detectors requires lengthy and costly experiments. The many attempts to reduce the effort spent in this process using simulations with Monte Carlo codes obtained efficiency and response of the detectors that did not reach the required accuracy when not guided by complementary experiments. This work reports the methodologies we developed to obtain the response and efficiency of detectors with good accuracy, combining experiment, simulation and the construction of analytic functions. Both the simulations and the analytical expressions took into account physical parameters, such as crystal dimensions, thicknesses of dead layers and other components of the detector, which were measured, modeled and/or calculated to match, within the experimental uncertainty, the measured efficiency of collimated photon beams. Some of the these studies led to find one detection secondary effect not previously reported in the literature. The characterized detectors were used in several measurements of cross sections of the bremsstrahlung and the ionization of atomic inner shells with the São Paulo Microtron electrons beams, which brought new contributions to the study of the interactions of photons and electrons with matter.

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8-Oxygen

Sukhoruchkin

Soroko

2004

Tables of Proton and Α-Particle Resonance Parameters. Part 1

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Thick target photon yields and angular distributions for the 19F(p,αγ)16O source reaction at incident proton energies between 1.5 and 4.0MeV

Cited by 22 publications

References 17 publications

Detectors for intense, pulsed active detection

Detectors for intense, pulsed active detection

Detetores semicondutores de fótons na investigação das interações dos elétrons e fótons com a matéria

8-Oxygen

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