[en] In this work, we utilize direct ¹⁷O DNP for the characterization of non-protonated oxygens in heterogeneous catalysts. The optimal sample preparation and population transfer approach for ¹⁷O direct DNP experiments performed on silica surfaces is determined and applied to the characterization of Zr- and Y-based mesoporous silica-supported single-site catalysts.

[en] Cross sections for the ¹⁷O(n,p)¹⁷N (T_1/2 = 4.7 s) reaction in the energy region between 13.7 and 14.9 were measured by the activation method using the Fusion Neutronics Source (FNS) at the Japan Atomic Energy Research Institute. Cross sections for the reaction obtained were 23 ± 5, 11 ± 4, and <7 mb at 14.9 ± 0.1, 14.4 ± 0.1, and 13.7 ± 0.1 MeV, respectively. This work uniquely gives the experimental partial excitation function for the ∼14-MeV reaction

[en] Because of the still present uncertainties on its rate, the ¹⁷O(p,α)¹⁴N is one of the most important reaction to be studied in order to get more information about the fate of ¹⁷O in different astrophysical scenarios. The preliminary study of the three-body reaction ²H(¹⁷O,α¹⁴N)n is presented here as a first stage of the indirect study of this important ¹⁷O(p,α)¹⁴N reaction through the Trojan Horse Method (THM)

[en] Using Q-box techniques, linked expansions in terms of the number of folds are carried out for j = 5/2, 1/2 and 3/2 states of ¹⁷O, where the complete 0 + 2(h/2π)ω space is included. These expansions are shown to converge very quickly and are compared to energy matrix diagonalizations. The series involved in obtaining the archetypal Q-boxes however converges rather slowly in this space. Calculations are performed for various shift operators with the original and modified Sussex matrix elements. (Auth.)

[en] O-17 NMR imaging is shown to be a valuable alternative or complement to proton imaging. The properties of this nucleus, generally believed 'unfavorable' for such applications, can in fact be turned into an advantage, and excellent images can be obtained. Moreover, the presence of O-17 in H₂O at various levels of enrichment can drastically affect relative intensities in proton images. Thus, the O-17 nucleus can constitute a useful, nontoxic, direct and indirect contrast agent in magnetic resonance imaging. After a brief presentation of the principles of MRI, biomedical, biological and materials research applications are described in this paper. The prospects for using O-17 in imaging and localized spectroscopy are discussed in the conclusion. (author). 8 refs.; 9 figs.; 1 tab

[en] Direct laboratory measurements of astrophysically important nuclear reactions become increasingly more difficult as regions of lower bombarding energies are being explored. As examples for these challenging experiments, we will report on recent measurements of the ¹⁷O(p,γ)¹⁸F and ²³Na(p,γ)²⁴Mg reactions at the Laboratory for Experimental Nuclear Astrophysics (LENA). We will discuss a typical experimental setup, will present recent experimental results, and will describe their impact on stellar nucleosynthesis

[en] It is shown that the magnetic elastic form factor of ¹⁷O can be accounted for by current nuclear theory. After making allowance for theoretical uncertainties regarding the high-q behavior of the M1 and M3 form factors, the rms radius of the 1d/sub 5/2/ neutron orbit is found to be 3.56 +- 0.09 fm. Quantitative information on the quenching of the M3 and M5 multipoles is also deduced

No abstract available

[en] The contribution of the giant dipole resonance to the Coulomb excitation of ¹⁷O by ²⁰⁸Pb has been measured to be 5.7 +- 0.4 times the value given by the hydrodynamic model. This result has significant implications for the determination of B(E2) values and quadrupole moments from Coulomb excitation measurements

[en] The delayed neutron spectrum following β^- decay of the 4.17 sec ¹⁷N has been measured with high-resolution ³He spectrometers. The intensities of the neutron branches from levels in ¹⁷O at 4549.3 +- 1.3, 5081 +- 21, 5387.1 +- 1.2 and 5949.9 +- 1.9 keV excitation energy result in ¹⁷N β^- transitions of (34.8 +- 2.6), (0.6 +- 0.4), (52.7 +- 3.5) and (7.0 +- 0.5)%, respectively. The neutron widths of these states were determined as 54.8 +- 0.4, 113 +- 55, 63.2 +- 1.1 and 60.5 +- 3.2 keV, respectively, in disagreement with previously reported values. The results are compared with theoretical calculations and with the mirror decay of ¹⁷Ne. (Auth.)