A two-neutron unbound excited state of 24 O was populated through a (d,d') reaction at 83.4 MeV/nucleon. A state at E = 715 ± 110 (stat) ±45 (sys) keV with a width of Γ < 2 MeV was observed above the two-neutron separation energy placing it at 7.65 ± 0.2 MeV with respect to the ground state. Three-body correlations for the decay of 24 O → 22 O + 2n show clear evidence for a sequential decay through an intermediate state in23 O. Neither a di-neutron nor phase-space model for the three-body breakup were able to describe these correlations.

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Two low-lying neutron-unbound excited states of 24 O, populated by proton-knockout reactions on 26 F, have been measured using the MoNA and LISA arrays in combination with the Sweeper Magnet at the Coupled Cyclotron Facility at the NSCL using invariant mass spectroscopy. The current measurement confirms for the first time the separate identity of two states with decay energies 0.51(5) MeV and 1.20(7) MeV, and provides support for theoretical model calculations, which predict a 2 + first excited state and a 1 + higher energy state. The measured excitation energies for these states, 4.70(15) MeV for the 2 + level and 5.39(16) MeV for the (1 + ) level, are consistent with previous lower-resolution measurements, and are compared with five recent model predictions.

We propose to perform the first measurement of the neutron–neutron scattering cross section in the through-channel of the pulsed aperiodic reactor YAGUAR (Snezhinsk, Russia). Such a measurement directly determines the neutron–neutron scattering length, and by comparison with the proton–proton scattering length bears upon the issue of charge symmetry of the nuclear force. The proposed experimental set-up, as well as modelling of the neutron density and of the frequency of neutron–neutron collisions is described. Experimental results are reported on the formation and optimization of the thermal neutron field inside the through-channel of the reactor YAGUAR. The instantaneous value of 1.1 × 1018 cm−2 s−1 obtained for the thermal neutron flux density is large enough to perform the first direct neutron–neutron scattering length measurement.

A bistable flexible electronic display has been developed based on photographic technology, processes, and materials. Using photographic film coating techniques, an aqueous cholesteric liquid crystal dispersion, a dielectric layer, and a dark layer were deposited onto patterned transparent conductors on a polymeric web. Second conductors were printed over the active display layers to complete display manufacture in a roll‐to‐roll process. Simple seven‐segment displays and matrix displays have been generated using these techniques. The displays can use contact electronics to eliminate drive cost from the displays. Several prototype applications were demonstrated. Displays produced with these processes were low‐cost, thin, flexible, passively driven, and retained an image without an applied electric field.