First operation of the charge-breeder electron-cyclotron-resonance ion source at the Texas A&M Cyclotron Institute.
The 14.5 GHz electron-cyclotron-resonance ion source (ECRIS) designed and fabricated specifically for charge breeding has been installed at the Texas A&M University Cyclotron Institute for use in the institute's ongoing radioactive-ion-beam upgrade. The initial testing of the source has just begun with magnetic analysis of the ECRIS beam. The source has only been conditioning for a brief time at low microwave power, and it is continuing to improve. After the source has been conditioned and characterized, charge-breeding trials with stable beams from a singly ionizing source will begin.
The ISOL-MAFIOS Source (invited)
ISOL–MAFIOS is a high‐efficiency Min B ECRIS charge state breeder for short‐lived ISOL beams in the PIAFE project. The ISOL species issuing from a bombarded target are locally ionized (1+) in a given ion source (ISOLDE type). They are then accelerated, magnetically selected, and transported in a long beam line, before being adequately introduced into ISOL–MAFIOS operating in continuous mode. In this system, an ECR plasma (created with a support gas) replaces the usual solid catcher. The ISOL–MAFIOS system captures the (1+) ions and transforms them into (q+) ions. If we call, overall efficiency of ISOL–MAFIOS the ratio of the beam intensities: I(q+) after the magnetic selector/I(1+) before entering in the source, we find for example for Rubidium IRb9+/IRb1+≊120 enA/1000 enA and a ratio at least two times larger for IKr9+/IKr1+. Moreover, an even more important result of ISOL–MAFIOS is that the release time+ionization time is of the order of 10−2 s instead of many seconds for a solid‐state catcher. Thus in ...
Nonsingular multidimensional cosmologies with Lobachevsky spatial sections
Examples of nonsingular cosmological models are presented on the basis of exact solutions to multidimensional gravity equations. These examples involve pure imaginary scalar fields, or, in other terms, “phantom” fields with an unusual sign of the kinetic term in the Lagrangian. We show that, with such fields, hyperbolic nonsingular models with a cosmological bounce (unlike spherical and spatially flat models) emerge without special relations among the integration constants, i.e., without fine tuning. In such models, the extra-dimension scale factors as well as scalar fields evolve smoothly between different finite asymptotic values. Examples of theories which create phantom scalar fields are obtained from string-inspired multidimensional field models and from theories of gravity in integrable Weyl space-times.