Hyperfine decoupling and pulsed dynamic nuclear polarization (DNP) are promising techniques to improve high field DNP NMR. We explore experimental and theoretical considerations to implement them with magic angle spinning (MAS). Microwave field simulations using the high frequency structural simulator (HFSS) software suite are performed to characterize the inhomogeneous phase independent microwave field throughout a 198 GHz MAS DNP probe. Our calculations show that a microwave power input of 17 W is required to generate an average EPR nutation frequency of 0.84 MHz. We also present a detailed calculation of microwave heating from the HFSS parameters and find that 7.1% of the incident microwave power contributes to dielectric sample heating. Voltage tunable gyrotron oscillators are proposed as a class of frequency agile microwave sources to generate microwave frequency sweeps required for the frequency modulated cross effect, electron spin inversions, and hyperfine decoupling. Electron spin inversions of stable organic radicals are simulated with SPINEVOLUTION using the inhomogeneous microwave fields calculated by HFSS. We calculate an electron spin inversion efficiency of 56% at a spinning frequency of 5 kHz. Finally, we demonstrate gyrotron acceleration potentials required to generate swept microwave frequency profiles for the frequency modulated cross effect and electron spin inversions.

The structure of the extremely proton-rich nucleus 11 8 O3, the mirror of the two-neutron halo nucleus 11 3 Li8, has been studied experimentally for the first time. Following two-neutron knockout reactions with a 13 O beam, the 11 O decay products were detected after two-proton emission and used to construct an invariant-mass spectrum. A broad peak of width ∼3 MeV was observed. Within the Gamow coupled-channel approach, it was concluded that this peak is a multiplet with contributions from the four-lowest 11 O resonant states: J π =3/2 − 1 , 3/2 − 2 , 5/2 + 1 , and 5/2 + 2. The widths and configurations of these states show strong, non-monotonic dependencies on the depth of the p-9 C potential. This unusual behavior is due to the presence of a broad threshold resonant state in 10 N, which is an analog of the virtual state in 10 Li in the presence of the Coulomb potential. After optimizing the model to the data, only a moderate isospin asymmetry between ground states of 11 O and 11 Li was found.

Particle-decaying states of the light nuclei 11,12 N and 12 O were studied using the invariant-mass method. The decay energies and intrinsic widths of a number of states were measured, and the momentum correlations of three-body decaying states were considered. A second 2p-decaying 2 + state of 12 O was observed for the first time, and a higher energy 12 O state was observed in the 4p+2α decay channel. This 4p+2α channel also contains contributions from fission-like decay paths, including 6 Beg.s.+ 6 Beg.s.. Analogs to these states in 12 O were found in 12 N in the 2p+ 10 B and 2p+α+ 6 Li channels. The momentum correlations for the prompt 2p decay of 12 Og.s. were found to be nearly identical to those of 16 Neg.s., and the correlations for the new 2 + state were found to be consistent with sequential decay through excited states in 11 N. The momentum correlations for the 2 + 1 state in 12 O provide a new value for the 11 N ground-state energy. The states in 12 N/ 12 O that belong to the A=12 isobaric sextet do not deviate from the quadratic isobaric multiplet mass equation (IMME) form.

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We study the sequential breakup of E/A=24.0  MeV ^{7}Li projectiles excited through inelastic interactions with C, Be, and Al target nuclei. For peripheral events that do not excite the target, we find very large spin alignment of the excited ^{7}Li projectiles longitudinal to the beam axis. This spin alignment is independent of the target used, and we propose a simple alignment mechanism that arises from an angular-momentum-excitation-energy mismatch. This mechanism is independent of the potential used for scattering and should be present in many scattering experiments.