[en] Full text: There are a number of nuclear reaction processes that involve, synthesise and influence isotopes on the proton-rich side of stability. Consequently, a variety of experimental techniques are needed to study the key reaction cross sections. This talk will discuss some of the techniques exploited, their advantages and limitations, with an emphasis on inverse kinematics. Examples from the γ-process, αp-process and HCNO cycle will be outlined.

[en] The first commercial nuclear power stations started operation around sixty years ago. On June 27, 1954, the USSR Obninsk NPP became the world's first nuclear power plant to generate electricity for a power grid, producing 5 MW(e). Beznau NPP (Switzerland) hosts the oldest civil nuclear power plant in the world that remains in operation today - a twin PWR 1130 MW(Th), 365 MW(e). Civil Nuclear Power naturally started small. As of 2017 IAEA states that >50 reactors of Generation III reactor design, are under construction around the world. Nuclear Power is converging to implicitly safer designs. The European PWR (EPR) design objectives are increased safety and enhanced economic competitiveness based on a power output of 1650 MW(e), 4500 MW(Th). However, plans for deployment are being shelved in most European countries in preference to life extension. In a world where politicians consider life post Fukushima within a low carbon/low greenhouse gas economy few European countries are now prepared to commit to new large civil build; and those who are face enormous cost and schedule performance challenges during construction. The WNA states that 25% of global energy will be nuclear by 2050 and 1000 GW of new capacity will be online by 2050 (Harmony). This endeavour will require cooperative effort and convergence. The key challenge is to develop and deploy power plants with sufficient capacity and flexibility to meet this demand for energy whilst simultaneously reducing emissions. Small Modular Reactors (SMRs) are progressively being proposed as a favoured choice but as of yet no investor /utility /government has committed to implementation. With high capital costs of EPR and other large scale NPPs, and limited international investors, are things about to change? The talk is aimed to promote discussion on the class of post 2040 nuclear reactor that will prevail. Focussing on the existing LWR life cycle, size and modularity, it may well be that smaller reactors may become the only choice for international energy policy makers and investors. The economic and social boundaries for the deployment of SMRs will be explored on the basis that there may be an absolute truth in the assumptions that a) international collaboration is the only way, and b) one size/one flavour of modular power block may fit all uses. An optimised ISMR (International SMR) may need to be small - but if so how small is small and what do the current vendors offer? (author).

[en] During the slow neutron capture process in massive stars, reactions on light elements can both produce and absorb neutrons thereby influencing the final heavy element abundances. At low metallicities, the high neutron capture rate of ¹⁶O can inhibit s-process nucleosynthesis unless the neutrons are recycled via the ¹⁷O(α, n)²⁰Ne reaction. The efficiency of this neutron recycling is determined by competition between the ¹⁷O(α, n)²⁰Ne and ¹⁷O(α, γ)²¹Ne reactions. While some experimental data are available on the former reaction, no data exist for the radiative capture channel at the relevant astrophysical energies. The ¹⁷O(α, γ)²¹Ne reaction has been studied directly using the DRAGON recoil separator at the TRIUMF Laboratory. The reaction cross section has been determined at energies between 0.6 and 1.6 MeV Ecm, reaching into the Gamow window for core helium burning for the first time. Resonance strengths for resonances at 0.63, 0.721, 0.81 and 1.122 MeV Ecmhave been extracted. The experimentally based reaction rate calculated represents a lower limit, but suggests that significant s-process nucleosynthesis occurs in low metallicity massive stars.

[en] A radioactive ion beam of ⁶He produced via the ⁷Li (p,2p) ⁶He reaction with typical intensity of 3x10⁶ was elastically scattered from LiF (Au) targets. Elastic scattering of ⁶He at E_lab = 27 MeV with ¹⁹⁷Au have been measured in the angular range of 6 ^dig-72 ^dig in the laboratory system employing lead and lamp detection system. Optical model calculations have been used to fit the data

[en] The requirements of the Laser Fusion Program place severe demands on the ability to monitor the important parameters of the laser beams. This has resulted in the development of novel and imaginative methods to provide the various required measurements. The design and implementation of a beam-diagnostics system for the Helios laser fusion facility at Los Alamos are described

[en] We measured the ⁷Be(p,γ)⁸B cross section from E_p = 221 keV to 1376 keV. A uniformly distributed beam that illuminated the whole area of a small diameter target was used to eliminate systematic error from ⁷Be target non-uniformity. The energy loss profile of the target to the incident beam was measured using the ⁷Be(α,γ)¹¹C resonance at E_α 1376 keV. The (α,γ) measurement also demonstrated that the target had a high ⁷Be atomic purity. The measured yield of the detected ⁸B was normalized to the activity of the target and the solid angle of the counting detector. Corrections for ⁸B decay during bombardment and arm rotation were applied. For the first time, the correction due to lost ⁸B from backscattering was determined experimentally. A new experiment is presently underway, extending to lower proton energy. Due to a problem in the determination of the α-detector solid angle in the first measurement, the solid angle in the new measurement will be determined by a different technique using a ¹⁴⁸Gd α source and a silicon detector whose distance to the source can be precisely adjusted

[en] A new detector - TACTIC - for nuclear reactions is under development at TRIUMF. The cylindrical ionization chamber allows the three-dimensional reconstruction of particle tracks by means of a two-dimensional anode array combined with a TOF measurement of the drift electrons. The geometry of TACTIC covers a large angular range permitting the measurements of differential cross-sections over a large solid angle. It will be ideal for investigations of nuclear processes pertinent to the field of nuclear astrophysics. TACTIC is useful in particular for experiments on gas targets with low-energy ejectiles that cannot penetrate a gas cell window, or for experiments with a high number of background particles that can't be separated by conventional methods. The first planned experiment is the measurement of the ⁸Li(α,n)¹¹B reaction, which can serve as an indicator for the nucleosynthesis of higher elements in the Big Bang Nucleosynthesis as well as one starting point of the r-process to bridge the mass-8 gap. (author)

[en] Space-based gamma-ray satellites such as BeppoSAX, COMPTEL and INTEGRAL have reported detection of ⁴⁴Ti in the Cassiopeia-A and SN1987a core-collapse supernova remnants. The NuSTAR satellite has recently measured the distribution of ⁴⁴Ti gamma ray emission in Cassiopeia-A finding a highly asymmetric distribution. In all cases, the amounts of ⁴⁴Ti inferred in the ejecta are higher than is expected, even assuming a wide range of progenitor models and masses. The dominant nuclear uncertainty within such models is the rate of the ⁴⁴Ti(α, p)⁴⁷V nuclear reaction rate. Through radiochemical separation, a sample of ⁴⁴Ti was obtained from highly-irradiated martensitic steel accelerator components of the Paul Scherrer Institute. Transported to CERN, this material was then developed into a beam at the REXISOLDE facility and directed onto a gas filled cell. This enabled a study of the ⁴⁴Ti(α, p)⁴⁷V reaction at an energy of Ecm=4.15 MeV, finding an upper limit for the cross section of 40 μ barn (68% c.l.). Implications for core collapse supernovae and plans for future experiments will be presented. (author)

[en] A routine inspection on Hex No. 6 boiler at Chapelcross nuclear power station revealed the existence of a crack in the bottom dome of the boiler. To enable continued operation of the boiler, it was required that the crack be repaired. Due to the position of the repair in the boiler it was undesirable to carry out post-weld heat treatment (PWHT) as the process could cause damage to neighbouring components and attachments. MBEL was engaged by BNFL to take part in a programme to investigate a non-PWHT repair methodology which would not compromise the structural integrity of the vessel and would satisfy the stringent safety requirements of the Nuclear Installations Inspectorate. Using the latest finite-element modelling techniques, in conjunction with experimental measurements made both on specimens and on the boiler shell, a full residual stress analysis of the repair was carried out which showed that the tolerable defect size in the repair was increased to a level within the non-destructive testing detection range. The employment of the foregoing methods has enabled the BNFL programme to justify a non-PWHT repair to the boiler. (author)

[en] An in-depth characterization of the TACTIC detector was performed using data from a ¹⁴⁸Gd alpha source and some test runs with a stable ion beam. The detector is an active target time-projection chamber with a blind central region for maximizing beam tolerance and GEM-based electron amplification, equipped with a modern digitizing data acquisition system allowing the recording of full signals. The system was developed to study the reaction ⁸Li(α,n)¹¹B, which is important for bridging the mass 8 gap in scenarios of low ⁴He density like Inhomogeneous Big Bang Nucleosynthesis and the production of r-process seeds in supernovae. Both energy resolution and tracking accuracy were found to agree with theoretical predictions and Geant4 simulations. The ⁸Li beam rate capability of the system is predicted to be of the order of 10⁵s⁻¹, several orders of magnitude higher than most previous measurements of the same reaction, while still maintaining a high detection efficiency of 70% to 80 %. (paper)