D.P. Sanderson

Performance of the high-energy single-event effects test Facility (SEETF) at Michigan State university's national Superconducting Cyclotron laboratory (NSCL)

The performance of Michigan State Universitys Single-Event Effects Test Facility (SEETF) during its inaugural runs is evaluated. Beam profiles and other diagnostics are presented, and prospects for future development and testing are discussed.

Two-proton correlation functions for equilibrium and non-equilibrium emission

Abstract Two-proton correlation functions are compared for equilibrium and non-equilibrium emission processes investigated, respectively, in “reverse kinematics” for the reactions 129 XE+ 27 Al and 129 Xe+ 122 Sn at E A = 31 MeV and in “forward kinematics” for the reaction 14 N+ 197 Au at E A = 75 MeV . Observed differences in the shapes of the correlation functions are understood in terms of the different time scales for equilibrium and preequilibrium emission. Transverse and longitudinal correlation functions are very similar.

Progress report on the small isochronous ring project at NSCL

The small Isochronous Ring (SIR), whose main objectives are experimental studies of space charge effects in the isochronous regime and validation of space charge codes, is under development at the National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University (MSU). The ring is a small-scale experiment that simulates the dynamics of intense beams in large-scale accelerators. It will store hydrogen and deuterium ions at energies of approximately 20-30 keV for a few tens of turns. The low beam energy and the small scale of the experiment provide a unique opportunity to perform accurate experiments on space charge dominated beams that are difficult to conduct in large-scale accelerators because of power and timing limitations imposed on beam diagnostics. The paper reports the status of the project and describes the progress in the development of ring subsystems.

Detailed test of distorting potentials for the transfer reactions 40Ca(7Li, 6Li/6He)

Abstract Angular distributions for the transfer reactions 40 Ca( 7 Li, 6 Li) 41 Ca and 40 Ca( 7 Li, 6 He) 41 Sc have been measured at 34 MeV, in small angular increments out to angles where the cross section has fallen by four orders of magnitude. Finite range DWBA calculations show a high sensitivity to different distorting potentials at the largest angle cross sections. It is found that a combination of Woods-Saxon and double-folded potentials does the best job of reproducing the data over the whole angular range.

Testing of a superconducting spectrometer dipole

A superconducting dipole magnet for use as spectrometer element has been constructed and is presently being mapped. The 75 ton dipole has a negative curvature side and a 15 cm gap. The cryostable coil produced a central field of 1.6 T at a current of 436 A. A second identical magnet is presently under construction. The authors describe the assembly and testing of the magnet.<<ETX>>

Method to test the adiabatic operation of a spin one vector polarized ion source

Abstract The dependence of the vector polarization produced in the weak field transition region on the direction of the static field gradient is investigated by means of experimental measurements and numerical calculations for a lithium source. The measurements employ a weak field transition apparatus whose tapered magnet is outside the vacuum and hence easily reversed and calculations are performed for several existing polarized ion sources. The results demonstrate that while the vector polarization depends on the direction of the static field gradient under nonadiabatic conditions, this dependence vanishes in the adiabatic limit. It is shown that the positive field gradient consistently produces higher vector polarization and that the independence of the vector polarization on the direction of the field gradient under adiabatic conditions provides a sensitive experimental test of the adiabatic operation of a vector polarized ion source.

Status and future prospects for polarized heavy-ion sources

A ground state atomic beam source for producing polarized 6 Li nuclei is described. Representative data which cross calibrates three existing sources for 6 Li → + 12 C at 20 MeV are presented. Possible future systems for producing polarized heavy-ion beams are discussed.