The IESP experiment measures the 6 components of the electromagnetic fluctuations in the ULF frequency range from 0.1 to 10 or 30 Hz, with a good sensitivity. After december 20, 1996 only the three electric components are received on the ground.
The magnetic components are measured with a triaxial search coil magnetometer designed for the lower ULF/ELF range of the MEMO experiment. It detects waves from 0.1 Hz to 1 kHz (See the description of the search coil magnetometer in the part devoted to MEMO). The magnetic signals come from MEMO to IESP through the NVKONCH experiment which also covers the frequency range from 5 Hz to 22 kHz.
The electric field is measured with 6 spheres (80 mm diameter provided by the SRI-BAN in Bulgary) mounted at the ends of long booms. The longest booms (about 22 m tip to tip) are in the spin plane. The pair ED1 and ED2 corresponds to Ey component and ED3 and ED4 to Ez component. The third pair of booms (ED5-ED6) is about 4.5 m long corresponding to the component Ex more or less aligned along the spin axis (ED5 makes an angle of 6° with respect to the spin axis in order to avoid shadowing effects on ED6). The IESP instrument provides electric signals to NVKONCH and MEMO.
The electric sensors ED1-ED6 consist of spherical probes made of graphite with glass-carbon cover. The sensor is built according to a classical design for double probe electric field measurements. Similar design has been used on many satellites (Mozer et al., 1978, Stanev et al., 1983, Pedersen et al., 1984). A preamplifier is placed inside the glass carbon sphere. It includes the high-resistance buffer-follower (DC), an amplifier for the AC component in the frequency range 5 Hz-20 kHz (AC) with a gain equal to 5. The current generator is in the range ±0.6 mA, which provides an optimum operation point for the current-voltage characteristic, a relay for connecting to the input the calibration signals provided by MEMO. Two symmetric electrodes (SE) are connected with the output of the buffer-follower and are therefore under the probe floating potential. The guarding electrode (G) must decrease the effect of the photoelectrons from the various elements of the satellite. This is achieved by commanding from the ground a fixed negative potential to the electrode from the range from 0 to -10 V. In practice, the guard voltage has been fixed at -2.65 V during the operations on board and the optimum bias current varies between -72 nA and -100 nA in the auroral region.
The main characteristics of the instrument are given below :
Version:2.4.0
The IESP experiment measures the 6 components of the electromagnetic fluctuations in the ULF frequency range from 0.1 to 10 or 30 Hz, with a good sensitivity. After december 20, 1996 only the three electric components are received on the ground.
The magnetic components are measured with a triaxial search coil magnetometer designed for the lower ULF/ELF range of the MEMO experiment. It detects waves from 0.1 Hz to 1 kHz (See the description of the search coil magnetometer in the part devoted to MEMO). The magnetic signals come from MEMO to IESP through the NVKONCH experiment which also covers the frequency range from 5 Hz to 22 kHz.
The electric field is measured with 6 spheres (80 mm diameter provided by the SRI-BAN in Bulgary) mounted at the ends of long booms. The longest booms (about 22 m tip to tip) are in the spin plane. The pair ED1 and ED2 corresponds to Ey component and ED3 and ED4 to Ez component. The third pair of booms (ED5-ED6) is about 4.5 m long corresponding to the component Ex more or less aligned along the spin axis (ED5 makes an angle of 6° with respect to the spin axis in order to avoid shadowing effects on ED6). The IESP instrument provides electric signals to NVKONCH and MEMO.
The electric sensors ED1-ED6 consist of spherical probes made of graphite with glass-carbon cover. The sensor is built according to a classical design for double probe electric field measurements. Similar design has been used on many satellites (Mozer et al., 1978, Stanev et al., 1983, Pedersen et al., 1984). A preamplifier is placed inside the glass carbon sphere. It includes the high-resistance buffer-follower (DC), an amplifier for the AC component in the frequency range 5 Hz-20 kHz (AC) with a gain equal to 5. The current generator is in the range ±0.6 mA, which provides an optimum operation point for the current-voltage characteristic, a relay for connecting to the input the calibration signals provided by MEMO. Two symmetric electrodes (SE) are connected with the output of the buffer-follower and are therefore under the probe floating potential. The guarding electrode (G) must decrease the effect of the photoelectrons from the various elements of the satellite. This is achieved by commanding from the ground a fixed negative potential to the electrode from the range from 0 to -10 V. In practice, the guard voltage has been fixed at -2.65 V during the operations on board and the optimum bias current varies between -72 nA and -100 nA in the auroral region.
The main characteristics of the instrument are given below :
| Role | Person | StartDate | StopDate | Note | |
|---|---|---|---|---|---|
| 1. | GeneralContact | spase://CNES/Person/CDPP-Archive/Mikhail.Mogilevsky |