NSSDCA ID: 1997-045A-03
Mission Name: ACEThe Ultra Low Energy Isotope Spectrometer (ULEIS) measures energetic ion fluxes over the charge range from He through Ni from about 20 keV/nucleon to 10 MeV/nucleon with mass resolution less than or equal to 0.3 amu. Ultra-heavy species (above Ni) are also measured in a limited energy range near 0.5 MeV/nucleon. The ULEIS telescope is a time-of-flight (TOF) mass spectrometer which identifies ions by TOF and by residual kinetic energy E of particles which enter the 24 deg. x 20 deg. aperture and stop in one of an array of silicon solid state detectors. The geometric factor is about one sq.cm.-sr. The TOF measurement is determined by start and stop signals from microchannel plate (MCP) assemblies detecting secondary electrons emitted from incident ion passage through a thin entrance foil and other such foils within the telescope. In order to prevent electronic pile-up during intense flux periods, a mechanical shutter ('iris') slides partially closed under on-board control dependent on the start MCP singles counting rate. The iris can decrease the ULEIS geometric factor by up to a factor of 100 during the most intense events. Full analysis of individual ions requires 128 bits/event for up to six events per second. Two types of rate data are included: sectored singles rates for each detector with 8 sectors for 18 rates at 12 bits/rate in compressed format; sectored counts of 5 particle species in 20 energy ranges and 8 sectors at 12 bits/s (compressed). These rate data are read out every 60 seconds at 189 b/s. Housekeeping and other miscellaneous data require 43 b/s, the total data rate being about 1 kbps. The ULEIS experiment manager is Dr. Robert E. Gold of the Applied Physics Laboratory of Johns Hopkins University.
Mass: 17 kg
Power (avg): 17.1 W
Bit rate (avg): 1 kbps
Questions and comments about this experiment can be directed to: Dr. John F. Cooper
Name | Role | Original Affiliation | |
---|---|---|---|
Dr. Glenn M. Mason | Co-Investigator | University of Maryland | Glenn.Mason@jhuapl.edu |
Dr. Robert E. Gold | Principal Investigator | Applied Physics Laboratory | robert.gold@jhuapl.edu |