Multi-energy analysis of SPREAdFAST proton events

<p>We present the procedure of event selection, data analysis and interpretation of solar energetic protons during the last solar cycle 24 for the needs of the SPREAdFAST project. Data from SOHO/ERNE and ACE/EPAM instruments have been analysed for nearly 100 proton events in the available energy bands. The energy dependence of the proton peak intensities and background spectra is completed. The energy range from a few to 130 MeV has been covered. Protons from the SPREAdFAST historical event list have been selected for a detailed comparative analysis. The validation between the observed and simulated proton events is presented and discussed.</p>

Response Functions of a Cs2LiYCl6 Scintillator to Neutron and Gamma Radiation

A new scintillator, CLYC, has been investigated for possible use in neutron spectrometry. This sensor provides neutron detection for both thermal and fast neutrons from the reactions 6Li(n,α) and 35Cl(n,p), respectively. This work primarily focuses on the detection of fast neutrons since there is currently no sensor that can accurately and efficiently provide information about their incident neutron energy. Conventional methods of fast neutron detection have been based on utilizing materials that use the elastic scattering process of neutrons on 1H to create recoil protons or by thermalizing and capturing these neutrons at thermal energies. Both approaches have drawbacks and are complex in deriving the energy spectrum through the unfolding process. The CLYC scintillator uses a distinct proton peak, whereby the position on the spectrum is proportional to the energy of the incident neutron. The response function of this detector has been simulated using Monte Carlo N-Particle eXtended code (MCNPX) for gamma-rays and neutrons of different energies. The obtained data has been discussed and analyzed.

Nuclear Magnetic Resonance Spectroscopic Analysis of Gossypol and Its Analogs in Cotton Flower Buds (Gossypium)

A specific nuclear magnetic resonance (NMR) method has been developed for determining gossypol and its analogs in the cotton flower bud. Gossypol and its related analogs, some of whose chemical structures have not yet been determined, can be identified by the distinctive NMR absorption of the aldehydic protons between 10.0 and 11.3 ppm. These compounds are quantitatively estimated by comparing the areas of the aldehydic proton absorptions with the aromatic proton peak (6.82 ppm) from p-dimethoxybenzene internal standard.

Nuclear magnetic resonance and ultraviolet studies of the effect of p2H on reduced nicotinamide–adenine dinucleotide

The effect of p2H on the chemical shifts of two adenine protons and one reduced nicotinamide proton of β-NADH have been examined. The adenine protons had a single pK at a p2H 3.85. The reduced nicotinamide proton showed no pK in the range p2H 3.00 to p2H 7.00. At low p2H values a new peak appeared in the nuclear magnetic resonance spectrum 0.31 p.p.m. downfield from the nicotinamide C-2 proton of β-NADH, and the nicotinamide C-2 proton peak gradually disappeared. It is suggested that this new peak is responsible for some of the anomalies in published results. The alterations in the ultraviolet spectra also indicate a change in the structure within the reduced nicotinamide moiety of β-NADH at low p2H values.