Nuclear reaction spectroscopy

Nuclear Reaction Spectroscopy Light element, isotope analysis H+D+He3+ 0.2-2MeV Reaction products Selected elements isotopes 1-10"4... 

Extensive research has been done on the nuclear structure of heavy elements using radioactive decay studies and high-resolution nuclear reaction spectroscopy. These investigations have provided important information to test and develop microscopic theoretical models. It has been established that nuclei with A 225 have spheroidal shape with major minor axes in the... 

Metastable quenching spectroscopy Nuclear Reaction Analysis Rutherford back-scattering spectroscopy (or HEIS high-energy ion scattering)... 

The composition of the Earth was determined both by the chemical composition of the solar nebula, from which the sun and planets formed, and by the nature of the physical processes that concentrated materials to form planets. The bulk elemental and isotopic composition of the nebula is believed, or usually assumed to be identical to that of the sun. The few exceptions to this include elements and isotopes such as lithium and deuterium that are destroyed in the bulk of the sun s interior by nuclear reactions. The composition of the sun as determined by optical spectroscopy is similar to the majority of stars in our galaxy, and accordingly the relative abundances of the elements in the sun are referred to as "cosmic abundances." Although the cosmic abundance pattern is commonly seen in other stars there are dramatic exceptions, such as stars composed of iron or solid nuclear matter, as in the case with neutron stars. The... 

The degree of activation of the sample is measured by post-irradiation spectroscopy, usually performed with high-purity semiconductors. The time-resolved intensity measurements of one of the several spectral lines enables to get the half-life of the radioactive element and the total number of nuclear reactions occurred. In fact, the intensity of a given spectral line associated with the decay of the radioactive elements decreases with time as Aft) = Aoexp[—t/r], where Aq indicates the initial number of nuclei (at t = 0) and r is the decay time constant related to the element half-life (r = In2/ /2), which can be measured. Integrating this relation from t = 0 to the total acquisition time, and weighting it with the detector efficiency and natural abundance lines, the total number of reactions N can be derived. Then, if one compares this number with the value obtained from the convolution of... 

Hodson J. 1988. The estimation of the photodegradation of organic compoundsby hydroxyl radical reaction rate constants obtained from nuclear magneticresonance spectroscopy chemical shift data. Chemosphere 17 2339- 2348. 

Zhang, Y., et al., Damage Evolution and Recovery on Both Si and C Sublattices in Al-Implanted 4H-SiC Studied by Rutherford Backscattering Spectroscopy and Nuclear Reaction Analysis, J. Appl. Phys., Vol. 91, No. 10, 2002, pp. 6388-6395. 

Another important characteristic is that ion beams can produce a variety of the secondary particles/photons such as secondary ions/atoms, electrons, positrons. X-rays, gamma rays, and so on, which enable us to use ion beams as analytical probes. Ion beam analyses are characterized by the respectively detected secondary species, such as secondary ion mass spectrometry (SIMS), sputtered neutral mass spectrometry (SNMS), electron spectroscopy, particle-induced X-ray emission (PIXE), nuclear reaction analyses (NRA), positron emission tomography (PET), and so on. 

However this does not mean that gamma-ray transitions in such nuclei are easy to detect. Usually we confront the competition of many nuclear reaction channels, which makes in-beam gamma-ray spectra too composite to analyze. In-beam gamma-ray spectroscopy through heavy-ion fusion is longing for a new method of selectively observing gamma-rays emitted via a nuclear reaction channel of particular interest. 

X-ray photoelectron spectroscopy (XPS), SIMS (Secondary Ion Mass Spectroscopy) and nuclear-reaction-based analyses (like RBS - Rutherford Backscattering -, and PIXE - Proton Induced X-ray Emission) have already proven their complementary potentialities. 

Another technique is the nuclear reaction analysis of Lanford et al. (1976), which was applied to NAMs by Rossman et al. (1988), Skogby et al. (1990), Maldener et al. (2001), and Bell et al. (2003). This technique has the advantage of yielding absolute hydrogen concentrations. It is a near-surface technique in which the hydrogen concentration is measured as a function of depth. The spatial resolution of the technique is at the millimeter level Bell et al. (2003) prepared polished surfaces 5x5 mm in area. Maldener et al. (2001) state that 1 mm diameter samples can be analyzed. This technique has been used to calibrate absorption coefficients for IR spectroscopy (e.g., Maldener et al., 2001 Bell et al., 2003). Bell et al. (2003) applied this technique to hydrogen in olivine, and found some of the previous estimates of hydrogen concentration in olivine need to be revised upward by factors between 2 and 4. Such a correction cannot be applied uniformly to all previous studies, because their new calibrations are specific to polarized spectra. 

Maldener J., Rauch F., Gavranic M., and Beran A. (2001) OH absorption coefficients of rutile and cassiterite deduced from nuclear reaction analysis and ETIR spectroscopy. Mineral. Petrol. 71, 21-29. 

TPR, Temperature-programmed reaction XPS, X-ray photoelectron spectroscopy IR, infrared spectroscopy H NMR, proton nuclear magnetic resonance spectroscopy UV-vis, ultraviolet-visible spectroscopy ESR, electron spin resonance spectroscopy TPD, temperature-programmed desorption EXAFS, extended X-ray absorption fine structure spectroscopy Raman, Raman spectroscopy C NMR, carbon-13 nuclear magnetic spectroscopy. 

For the analysis of the new surface after every removal one may use all the surface techniques already mentioned in Sect. 4.3.1 as long as their information depth does not exceed the thickness of the layer removed Auger and ESCA-spectroscopy, secondary-ion mass spectrometry (SIMS), backscattering, ion-induced X-ray and nuclear reaction analysis. In addition, one may investigate the content of the element of interest in the removed layer. Because of the low absolute concentration of implanted ions most of the standard methods of analysis fail. The best results come from implantations of radioactive elements followed by measuring the radioactivity of the dissolved removed layer. 

Spatial features of the brush profile are observed with the precision determined by the resolution p of depth profiling techniques used. The resolution p, described as a half width at half maximum (HWHM) of a Gaussian function, should be at least comparable with the unperturbed dimension of the brush, characterized by its radius of gyration Rg(N). Therefore nuclear reaction analysis [19] (NRA, p=8 nm), secondary ion mass spectroscopy [26, 27] (SIMS, p=... 

NAA is gamma ray spectroscopy that uses the slow thermal neutrons from a nuclear reactor to excite the nucleus of an atom. When an atom absorbs a thermal neutron, its atomic mass increases by one and the nucleus becomes unstable. One or more nuclear reactions then take place that release gamma-rays with energies characteristic of the particular nuclear decay reactions, along with other radiation (Fig. 4.14). While... 

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