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Photo-induced reaction cross section data are of importance for a variety of current or emerging applications, such as radiation shielding design and radiation transport analyses, calculations of absorbed dose in the human body during radiotherapy, physics and technology of fission reactors (influence of photo-reactions on neutron balance) and fusion reactors (plasma diagnostics and shielding), activation analyses, safeguards and inspection technologies, nuclear waste transmutation, medical isotope production and astrophysical applications. To address these data needs the IAEA Photonuclear Data library was produced in 1999, containing evaluated photo-induced cross sections and neutron spectra for 164 nuclides which were deemed relevant for the applications. Since the release of the IAEA Photonuclear Data Library however, new experimental data as well as new methods to assess the reliability of experimental cross sections have become available. Theoretical models and input parameters used to evaluate photo-induced reactions have improved significantly over the years. In addition, new measurements of partial photoneutron cross sections using mono-energetic photon beams and advanced neutron detection systems have been performed allowing for the validation of the evaluations and assessments of the experimental data. Furthermore, technological advances have led to the construction of new and more powerful gamma-beam facilities, therefore new data needs are emerging. We report our coordinated efforts to address these data needs and present the results of the new up-to-date evaluations included in the new updated IAEA Photonuclear Data Library consisting of 219 nuclides. The new library includes 188 new evaluations produced by the CRP evaluators, and one evaluation taken from the JENDL/PD-2016 library, while 20 evaluations were retained from the previous 1999 IAEA Photonuclear Data Library. In most of the cases, the photon energy goes up to 200 MeV. A total of 55 nuclides are new in this library reflecting the progress in measurements but also the developing data needs. In this paper we discuss the new assessment method and make recommendations to the user community in cases where the experimental data are discrepant and the assessments disagree. In addition, in the absence of experimental data, we present model predictions for photo-induced reaction cross section on nuclides of potential interest to medical radioisotope production.

Performance of the ELIGANT-GN array being developed at ELI-NP was evaluated using dedicated GEANT4 simulation code. The array is designed to consist of 17 LaBr3:Ce and 17 CeBr3 detectors as well as 33 BC501A and 29 6Li-glass detectors. The energy and time responses of the detectors were studied giving information on gamma and neutron absolute detection efficiencies of the array. A planned day-one experiment regarding the gamma and neutron decay from GDR in 208Pb is discussed and, based on simulations, the data analysis procedure is proposed. The detection efficiencies as well as the count rates estimations are presented.

Photoneutron measurements in the Giant Dipole Resonance region have been recently performed using quasimonochromatic Laser Compton Scattering γ -ray beams at NewSUBARU (Japan) for 59Co, 89Y, 103Rh, 139La, 159Tb, 165Ho, 169Tm, 181Ta, 197Au and 209Bi. Experimental ( γ , x n ) with x = 1 – 4 photoneutron cross sections have been obtained with a direct neutron-multiplicity sorting method associated to a flat-efficiency neutron detector , which operates under single firing conditions obtained by low reaction rates. In this paper, we discuss recent developments to the neutron-multiplicity sorting procedure dedicated to (i) resolving multiple firing events and to (ii) extracting the average energies of ( γ , x n ) photoneutrons. The method is tested on 159Tb experimental data.

The response function to high energy γ γ -rays of two large volume LaBr 3 :Ce crystals (3.5”x8”) and the linearity of the coupled PMT’s were investigated at the NewSUBARU facility, where γ γ -rays in the energy range 6 –38 MeV were produced and sent into the detectors. Monte Carlo simulations were performed to reproduce the experimental spectra. The photopeak and interaction efficiencies were also evaluated both in case of a collimated beam or an isotropic source.

A novel technique of direct neutron-multiplicity sorting with a flat-efficiency detector is proposed to resolve the long-standing discrepancy between the Livermore and Saclay data of partial photoneutron cross sections. A flat-response neutron detector with the detection efficiency of 36 . 5 ± 1 . 6 % over a neutron energy range 0.01–5.0 MeV was developed by optimizing triple-ring configurations of He proportional counters embedded in a polyethylene moderator. The technique forms a foundation of measuring cross sections with x = 1 − 3 for the photonuclear data project of the International Atomic Energy Agency. The methodology of direct neutron-multiplicity sorting and key experimental elements are presented.

The future prospects of photonuclear reactions studies at the new Extreme Light Infrastructure—Nuclear Physics (ELI-NP) facility are discussed in view of the pursuit of investigating the electromagnetic response of nuclei using γ-ray beams of unprecedented energy resolution and intensity characteristics. We present here the features of the γ-ray beam source, the emerging ELI-NP experimental program involving photonuclear reactions cross section measurements and spectroscopy and angular measurements of γ-rays and neutrons along with the detection arrays currently under implementation.

The synchrotron radiation facility NewSUBARU with nine beam-lines is operated by the Laboratory of Advanced Science and Technology for Industry, University of Hyogo, Japan. Gamma-ray beams are produced in the beam-line BL01 by laser Compton scattering (LCS) from 0.5–1.5 GeV electron beams in the NewSUBARU storage ring [1]. Lasers with different wavelengths are used to produce the LCS photon beam in the energy range from 0.5 MeV to 76 MeV: a Nd:YVO4 laser (λ = 1064 and 532 nm), a CO2 laser (λ = 10.59 μm), and an Er fiber laser (λ = 1540 nm). A new experimental hutch, GACKO (Gamma Collaboration Hutch of Konan University), was installed in the BL01 in March 2012.

Using $\gamma $ -ray beams produced in the inverse Compton scattering between ${\hbox{CO}}_2$ laser photons and relativistic electrons, we have calibrated electron beam energies in the nominal energy range 550–974 MeV at the synchrotron radiation facility NewSUBARU. The laser Compton-scattering (LCS) $\gamma $ -ray beams were produced at energies from 561 to 1728 keV and detected with a high-purity germanium detector. The electron beam energies were determined by reproducing the full energy peaks of the $\gamma $ -ray beams by Monte Carlo simulations. The accuracy of the calibration is $(5.5 - 9.4) \times {10^{ - 5}}$ . The reproducibility of the electron beam energy is excellent in an independent injection and deceleration. The present energy calibration of the electron beams offers a standard for the energy calibration of high-energy LCS $\gamma $ -ray beams produced with a ${\hbox{Nd:YVO}}_4$ laser. As applications of the energy calibration, we investigated the energy linearity of a $3.5^{\prime\prime} \times 4.0^{\prime\prime}$ ${\hbox{LaBr}}_3({\hbox{Ce}})$ detector in the response to $\gamma $ -rays at energies up to 10 MeV and the energy profile of the high-energy LCS $\gamma $ -ray beams.

An update of the NACRE compilation [3] is presented. This new compilation, referred to as NACRE II, reports thermonuclear reaction rates for 34 charged-particle induced, two-body exoergic reactions on nuclides with mass number A 16 , of which fifteen are particle-transfer reactions and the rest radiative capture reactions. When compared with NACRE, NACRE II features in particular (1) the addition to the experimental data collected in NACRE of those reported later, preferentially in the major journals of the field by early 2013, and (2) the adoption of potential models as the primary tool for extrapolation to very low energies of astrophysical S-factors, with a systematic evaluation of uncertainties. As in NACRE, the rates are presented in tabular form for temperatures in the 10 6 ≲ T ⩽ 10 10 K range. Along with the ‘adopted’ rates, their low and high limits are provided. The new rates are available in electronic form as part of the Brussels Library (BRUSLIB) of nuclear data. The NACRE II rates also supersede the previous NACRE rates in the Nuclear Network Generator (NETGEN) for astrophysics. [ http://www.astro.ulb.ac.be/databases.html ]

We measured pulse-height spectra of 16.7 MeV laser-Compton scattering photons with a 6 in.×5 in. NaI(Tl) detector for blank and three lead materials of 75.8, 50.9, and 25.9% transmissions at the NewSUBARU facility to investigate how the original Poisson distribution of the pulsed photons is modified after passing through thick-target materials. We present a well-prescribed method of determining the number of incident photons within 3.5% accuracy based on the response of the NaI(Tl) detector to the pulsed photon beams.

The universe is filled with cosmic microwave background radiation at 2.73 K (Figure 1). It is a relic of the “fire-ball” that the universe once underwent shortly after its birth. This is the lowest-temperature black-body radiation that mankind has ever witnessed. Where can we expect highest-temperature black-body radiations? An answer may be found in the explosion of massive stars. Stars more massive than 10 solar masses that are destined to die as type II supernovae (Figure 2) evolve to form an onion-like pre-supernova structure consisting of multi-layers of hydrogen, helium, carbon, silicon, and the iron core as dominant elements. The gravitational collapse of the iron core triggers the explosion. Typically energy of about 1% (~1051 erg) of the gravitational energy is sufficient to explode massive stars, blowing off the outer layers and leaving neutron-stars (black-holes) as remnants. During the supernova explosion, the shock wave propagates the outer layers and heats material behind it, making, for exa...

Photon-induced reactions play a key role in the nucleosynthesis of heavy neutron-deficient nuclei, the so-called p-nuclei. In this paper we review the present status of experiments on photon-induced reactions at energies of astrophysical importance and their relevance to p-process modeling., Comment: Nucl. Phys. A, in press

Direct determination of photoneutron cross sections of astrophysical importance has recently become possible with use of quasi-monochromatic γ beams produced in laser Compton backscattering (LCS) from relativistic electrons at AIST. The astrophysics to be discussed with the photodisintegration cross section are both stellar and big bang nucleosyntheses regarding the production of p-process and s-process nuclei as well as light elements. Synchrotron radiations from a 10 tesla superconducting wiggler (SCW) at SPring-8 serve as an ideal photon source to determine photoreaction rates. This paper covers the latest cross section measurements with the LCS photon beams and a feasibility study of determining (γ,x) (x = n, p, α) reaction rates with the SCW radiation.

The astrophysical reaction rates of the 16O(a,g)20Ne capture reaction and its inverse 20Ne(g,a)16O photodisintegration reaction are given by the sum of several narrow resonances and a small direct capture contribution at low temperatures. Although the thermal population of low lying excited states in 16O and 20Ne is extremely small, the first excited state in 20Ne plays a non-negligible role for the photodisintegration rate. Consequences for experiments with so-called quasi-thermal photon energy distributions are discussed.

A surface channel formed in a coaxial germanium detector degrades the pulse-height of output signals. The pulse-height degradation gives rise to an enhancement of low pulse-height events in γ -ray response functions at the cost of the full-energy peak. This phenomenon was closely examined for a twin coaxial-germanium detector. It was found that imperfect charge collection is primarily caused by p-type surface channels and supplemented by the n + –i and i– p + boundaries, producing low-energy events both in the valley between the full-energy peak and the Compton edge and on the hill below the Compton edge. It is shown that experimental response functions of the twin Ge can be reproduced with high precision by incorporating the imperfect charge collection in Monte Carlo simulations in a phenomenological way.

Cross sections of the 186W, 187Re, 188Os(γ,n) reactions were measured using quasi monochromatic γ-ray beams from laser Compton scattering (LCS), and results for the latter reaction are presented here. Neutron capture cross sections of the inverse reactions were evaluated by the Hauser-Feshbach statistical calculation where the experimental data were used to constrain the model parameters, especially the E1 strength function. The influence of the neutron capture by the 9.75 keV first excited state in 187Os which is substantially populated in stellar plasmas at typical s-process temperatures is examined in connection with the 187Re-187Os cosmochronology.

JSNS, the Japanese Spallation Neutron Source, is a forthcoming 1MW spallation neutron source. Since it is highly intense and has low background, it will provide a unique opportunity to study neutron-induced nuclear reactions relevant to astrophysics with excellent sensitivity and accuracy. Details of the JSNS facility and a plan for an experimental study of cosmonuclear physics are presented.

The 10-T superconducting wiggler at SPring-8 is an ideal photon source for nuclear astrophysics experiments because it produces high-energy synchrotron radiations with equivalent blackbody temperatures being billions of Kelvin. We discuss the characteristics of the high-energy radiation from the superconducting wiggler and its applications to ( γ ,n) measurements.

New α-ray beams at synchrotron radiation facilities will give us unprecedented opportunities to study photonuclear reactions of astrophysical interest. Konan University and the Universite Libre de Bruxelles launch a 5-year project, starting in 2004, of constructing ari extended NACRE compilation in which photonuclear reactions obtained within a dedicated international effort will be included. © 2004 Elsevier B.V. All rights reserved.

Intrinsic excitation of α cluster in A = 6 nuclei were searched for by using the 6Li(3He, t) and 6Li(7Li,7Be) charge exchange reactions at the incident energy of 450 and 455 MeV at 0°. Charged particle decay from the dipole resonance at around 25 MeV in 6Be and 6He was measured. The dominant decay channels of the resonance are found to be d+3He+n for 6Be and d+t+p for 6He. The invariant mass spectra for 3He+n and 3H+p show clear enhancement in comparison with phase-space spectra, and suggests that α cluster in 6Be and 6He are excited to 4Li and 4H.