Lithium beam energy-momentum correlations on PBFAII

The correlation between the energy and canonical angular momentum of a Li beam generated with a 15-cm-radius applied-B-field ion diode on PBFAII is measured with a magnetic spectrometer for the purpose of determining the character of instabilities in the virtual cathode of the diode. The spectrometer has been previously used for the purpose of measuring beam energy and energy spread for the beam generated by PBFAII. It is configured with a 30 cm diameter 7.1 kG permanent magnet with pin diodes and CR39 track recording plastic ion detectors. A 1.2-mm-diameter aperture located 73 cm above the target at the entrance to the spectrometer acts to pinhole image the beam scattered from the target. A 4.5 mm slit located 15 cm above the target limits the vertical field of view on the target to 5.7 mm. The spectrometer was modified for this experiment by the inclusion of two additional rows of pin diodes to observe the beam scattered from the target 4.5 mm on either side of the centerline