Instruments
Electrostatic Analyzer
Table of eESA and iESA Parameters
Table of eESA and iESA Parameters (from McFadden, et al., 2008a)
| Parameter | Value | Comments |
| Electron Electrostatic Analyzer | Spherical top-hat | |
| ΔR/R | 0.06 | 37.5 mm inner hemisphere radius |
| Analyzer constant | 7.9 | 0 to 4 kV sweep supply |
| Energy Range | 2 eV to 32 keV | |
| Analyzer Energy Resolution | 17% (15%) | ΔE/E measured (predicted) |
| Measurement Energy Resolution | 32% | Typical 31-step log energy sweep |
| Energy Sweep Rate | 32 per spin | ~94 ms for nominal 3s spin |
| Instantaneous Field of View | 180° x 6° FWHM | 180° centered on spin plane |
| Anode Angle Resolution | 22.5° | 8 anodes |
| Field of View each spin | 4π | steradians |
| Analyzer Geometric Factor | 0.0075 cm²-sr-E 0.0047 cm²-sr-E | Predicted from simulations, analyzer only One 90% exit grid and 70% MCP efficiency |
| Sensor Geometric Factor | 0.0066 cm²-sr-E | From in-flight calibration, includes grid losses, MCP efficiency @ 10eV |
| Counter readout | 1024 per spin | ~3 ms |
| Full Distribution Array | 32E x 88Ω | 32 or 128 spin cadence, continuous |
| Burst Distribution Array | 32E x 88Ω | 1 spin cadence, 30-60 min/orbit |
| Reduced Distribution Array | 32E x 6Ω or 32E x 1Ω | 1 spin cadence, continuous, 6Ω in FS mode 1Ω in SS mode |
| Ion Electrostatic Analyzer | Spherical top-hat | |
| ΔR/R | 0.075 | 37.5 mm inner hemisphere radius |
| Analyzer constant | 6.2 | 0 to 4 kV sweep supply |
| Energy Range | 1.6 eV to 25 keV | |
| Analyzer Energy Resolution | 18% (19%) | ΔE/E measured (predicted) |
| Measurement Energy Resolution | 32% | Typical 31-step log energy sweep |
| Energy Sweep Rate | 32 or 64 per spin | 64/spin in solar-wind mode with 16 energies |
| Instantaneous Field of View | 180° x 6° FWHM | 180° centered on spin plane |
| Anode Angle Resolution | 5.6° to 22.5° | 16 anodes |
| Field of View each spin | 4π | steradians |
| Analyzer Geometric Factor | 0.0181 cm²-sr-E 0.0073 cm²-sr-E | Predicted from simulations, analyzer only Two 90% grids and 50% MCP efficiency |
| Sensor Geometric Factor | 0.0061 cm²-sr-E | From in-fligt calibration, includes grid losses and MCP efficiency @ 500eV |
| Counter readout | 1024 per spin | ~3 ms |
| Full Distribution Array | 32E x 88Ω | 32 or128 spin cadence, continuous |
| Burst Distribution Array | 32E x 88Ω | 1 spin cadence, 30-60 min/orbit |
| Reduced Distribution Array | 24 E x 50Ω or 32E x 1Ω | 1 spin cadence, continuous, 50Ω in FS mode 1Ω in SS mode |