UVCS Detectors

OVI Detector:

Behavior is "nominal:" we continue to acquire high quality O VI (and other) line profiles and/or intensities via the "direct" optical path and, simultaneously, H I LYA (and other) line profiles via the "redundant" optical path.

We see no alarming trends in low or high voltage current draw.

High Voltage has been increased three times since the beginning of mission. Enough margin exists for 9 more similar increases.

LYA Detector:

Behavior is NOT "nominal": beginning in the summer of '97 we noticed an alarming trend (evidently temperature correlated) in the current drawn by the MCPs and decided to operate at reduced HV (reduced gain) in order to reduce the risk of current runaway.

Calibration measurements were made in '97-'98 to correct data for the change in gain.

Post-recovery behavior has been more or less a continuation of the behavior before the mission interruption

A "hot-spot" appeared in spectra obtained during the SOHO-SPARTAN joint observations. It was transient: it appeared then disappeared. The detector HV is currently off while we investigate this newest problem.