About ULEIS Data

Sensor Full Name Measured Species Measured Quantities Energy Range (MeV/nuc.) Measurement Technique


Ultra Low Energy Isotope Spectrometer 1 <= Z <= 30 Z, M, E ~ 0.02 - 14 TOF - E

The ULEIS Instrument on ACE

ULEIS measures ion fluxes over the charge range from H through Ni from about 20 keV/nucleon to 10 MeV/nucleon, thus covering both suprathermal and energetic particle energy ranges. Exploratory measurements of ultra-heavy species (mass range above Ni) will also be performed in a more limited energy range near 0.5 MeV/nucleon. ULEIS will be studying the elemental and isotopic composition of solar energetic particles, and the mechanisms by which these particles are energized in the solar corona. ULEIS will also investigate mechanisms by which supersonic interplanetary shock waves energize ions.

For more information about the ULEIS instrument, visit the ULEIS Home Page, at JHU/APL.

ULEIS Data Description

Time Data
All level 2 data records for all ACE instruments contain timing information in the same format. The format of the timing information is described

Element Fluxes
ULEIS level 2 data is organized into 27-day time periods (Bartels Rotations - roughly one solar rotation period). For each Bartels Rotation, the level 2 data contains time averages of energetic charged particle fluxes over the following time periods:

Currently, flux data are available for 7 species, in several energy intervals for each species. Flux data are in units of particles/(cm2 Sr sec MeV/nucleon).

The species for which data are available are:

The energy intervals available are different for each species - view the ULEIS Energy Passbands

Flux Uncertainties
Flux data uncertainties are derived from statistical (counting) errors only. The uncertainties are fractional uncertainties, and are given as 1/sqrt(N), where N is the number of events in the averaging period. For no events, an uncertainty value of -999.9 is given.

Release notes for ULEIS level 2 data - provided by the instrument teams. All users of ULEIS data should read these notes.

Other notes
A flux value of -999.9 indicates bad or missing data.

ULEIS level 2 data is an average over all sectors scanned by the instrument during a spacecraft spin-period.

Other species may be added to the ULEIS level 2 dataset in the future.

Download ULEIS level 2 data

Our Email Address: asc@srl.caltech.edu

Last Updated: 25 September, 2008

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