Cornell´s RECE-program on field-reversing electron and ion rings

During the last year, important results were obtained by the RECE-Program in various areas. On the larger RECE-Christa device: (i) the lifetime of rings in the field-reversed state has been extended to over 490 μsec providing for an increase of the field-reversal times by about 3 orders of magnitude since 1971 (ii) strong electron rings have been trapped close to the injector and then moved along the tank over a distance of 1.60 m without serious loss of strength (iii) field-reversal (106%) has now also been achieved by “stacking” of two electron rings (44% and 68% strength). A B_z-compression coil is now being incorporated into the device as preparation for long-lifetime and plasma confinement experiments. On the smaller RECE-Berta experiment, an extension of earlier measurements with quadrupole Ioffe winding indicate the presence anomalous fast-electron losses induced by these fields, probably due to orbital resonances. An analysis of trapping experiments in a preformed plasma show the trapping mechanism to be very different from that in gases. The Ion-Generation program has extended earlier micro-second pulse measurements into the MeV-range. The Theory Group has obtained various ring equilibria and now investigates the stability of such rings.