Abstract
Abstract. On board the four Cluster spacecraft, the Cluster Ion Spectrometry (CIS) experiment measures the full, three-dimensional ion distribution of the major magnetospheric ions (H+, He+, He++, and O+) from the thermal energies to about 40 keV/e. The experiment consists of two different instruments: a COmposition and DIstribution Function analyser (CIS1/CODIF), giving the mass per charge composition with medium (22.5°) angular resolution, and a Hot Ion Analyser (CIS2/HIA), which does not offer mass resolution but has a better angular resolution (5.6°) that is adequate for ion beam and solar wind measurements. Each analyser has two different sensitivities in order to increase the dynamic range. First tests of the instruments (commissioning activities) were achieved from early September 2000 to mid January 2001, and the operation phase began on 1 February 2001. In this paper, first results of the CIS instruments are presented showing the high level performances and capabilities of the instruments. Good examples of data were obtained in the central plasma sheet, magnetopause crossings, magnetosheath, solar wind and cusp measurements. Observations in the auroral regions could also be obtained with the Cluster spacecraft at radial distances of 4–6 Earth radii. These results show the tremendous interest of multispacecraft measurements with identical instruments and open a new area in magnetospheric and solar wind-magnetosphere interaction physics.Key words. Magnetospheric physics (magnetopause, cusp and boundary layers; magnetopheric configuration and dynamics; solar wind - magnetosphere interactions)
Highlights
The Cluster Ion Spectrometry (CIS) instrument on-board the Cluster mission has been described in detail in Reme et al (1997)
The primary purpose for introducing this scheme is to avoid a short-time gain depression of the microchannel plate (MCP) area, which would otherwise persist on the order of 1 s after the impulsive high count rate that would result from the solar wind
The TOF efficiency is a function of the ion species and the total energy, which is the sum of the original ion energy plus the energy gained in the post-acceleration potential
Summary
The CIS instrument on-board the Cluster mission has been described in detail in Reme et al (1997). – Have versatile and programmable operating modes and data processing routines to optimize the data collection for specific scientific studies and widely varying plasma regimes To satisfy all these criteria, the CIS package consists of two different instruments: a Hot Ion Analyser (HIA) sensor and a time-of-flight ion COmposition and DIstribution Function (CODIF) sensor. The CIS plasma package is versatile and is capable of measuring both the cold and hot ions of Maxwellian and non-Maxwellian populations (for example, beams) from the solar wind, the magnetosheath, and the magnetosphere (including the ionosphere) with sufficient angular, energy and mass resolutions to accomplish the scientific objectives. The time resolution of the instrument is sufficiently high to follow density or flux oscillations at the gyrofrequency of H+ ions in a magnetic field of 10 nT or less Such field strengths can be frequently encountered by the Cluster mission. This particle imaging is based on microchannel plate (MCP) electron multipliers and position encoding discrete anodes
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
