Neutron emission from a deuterium plasma pinch generated in a very small plasma focus (6 mm anode diameter) operating at only tens of joules is presented. A maximum current of 50 kA is achieved 140 ns after the beginning of the discharge, when the device is charged at 50 J (160 nF capacitor bank, 38 nH, 20–30 kV, 32–72 J). Although the stored energy is very low, the estimated energy density in the plasma and the energy per particle in the plasma are of the same order as in higher energy devices. The dependence of the neutron yield on the filling pressure of deuterium was obtained for discharges with 50 and 67 J stored in the capacitor bank. Neutrons were measured by means of a system based on a 3He proportional counter in current mode. The average neutron yield for 50 J discharges at 6 mbar was (1.2 ± 0.5) × 104 neutrons per shot, and (3.6 ± 1.6) × 104 for 67 J discharges at 9 mbar. The maximum energy of the neutrons was (2.7 ± 1.8) MeV. Possible applications related to substance detection and others are discussed.

A generalization of the Jordan-Wigner transformation to three (or higher) dimensions is constructed. The nonlocal mapping of spin to fermionic variables is expressed as a gauge transformation with topological charge equal to 1. The resulting fermionic theory is minimally coupled to a non-Abelian gauge field in a spontaneously broken phase containing monopoles.PACS numbers: 71.27.+a, 05.50.+q, 11.15.-q, 75.10.JmThe Jordan-Wigner (JW) transformation [1] for onedimensional spin systems has provided remarkable applications in condensed matter physics, including the twodimensional classical Ising model [2,3] and the XY spin-1/2 model [4], The counterpart in relativistic field theory, the bosonization of fermionic theories in 1+1 dimensions [5], has also opened an important field of active research.Bosonization in higher dimensions has been elusive for a long time. Relatively recent work has uncovered a Bose-Fermi transmutation in 2+1 dimensions which is experienced by the elementary excitations of the sigma model in the presence of a Chern-Simons field [6,7]. This result paved the way for the construction of the JW transformation in a lattice of two spatial dimensions, where a local fermion theory is mapped onto a system of hard-core bosons described by the Heisenberg Hamiltonian [8]. On the same basis, the bosonization scheme has been also implemented for 2+1 relativistic field theory [9].In this Letter, we propose an extension of the JW transformation to three-or more-dimensions. Here we discuss in detail the three-dimensional case. The generalization to higher dimensions is straightforward.The JW transformation relates the local spin-1/2 operators, S Z ,S ± ([S^S*] = ±S±, [5+,5-] = 2S*), to local fermionic operators, ip, ip^ ({^t/^} = 1> {ipii/>} = {^t,^t} = 0):

Chern-Simons (CS) forms generalize the minimal coupling between gauge potentials and point charges, to sources represented by charged extended objects (branes). The simplest example of such a CS-brane coupling is a domain wall coupled to the electromagnetic CS three-form. This describes a topologically charged interface where the CS form AdA is supported, separating two three-dimensional spatial regions in 3+1 spacetime. Electrodynamics at either side of the brane is described by the same Maxwell's equations, but those two regions have different vacua, characterized by a different value of the θ parameter multiplying the Pontryagin form F ∧ F . The θ-term is the abelian version of the concept introduced by 't Hooft for the resolution of the U (1) problem in QCD. We point out that CS-generalized classical electrodynamics shows new phenomena when two neighboring regions with different θ-vacua are present. These topological effects result from surface effects induced by the boundary and we explore the consequences of such boundary effects for the propagation of the electromagnetic field in Maxwell theory. Several features, including optical and electrostatic/magnetostatic responses, which may be observable in condensed matter systems, like topological insulators, are discussed.