ISO space radiation environment

Cosmic ray, trapped particle & solar flare radiation data and models 1995-1997


The first ISO Detector Workshop was held in Vilspa, Madrid, on 14-16 January 1998. A number of detailed technical reports of the performance of ISO detectors were presented in this workshop, along with more general discussions on space weather, transient effects and future detector strategies, particularly in view of the upcoming FIRST mission.


The purpose of these pages is to provide information on the radiation environment of the ISO orbit during the mission so far (1995-1998) for the analysis of the effects in the four ISO instruments (ISOCAM, ISOPHOT, ISOLWS, and ISOSWS).


It became apparent of this page in the Workshop that especially the study of the poorly undestood "glitch" phenomenon requires detailed knowledge of the cosmic ray environment, trapped electron and proton fluxes, and other space environmental parameters.


To complement the static particle models, real measurement data (unfortunately, apart from the ISOCAM RadFET, there was no radiation monitor directly onboard) and particle effect analysis are therefore to be considered.


The interactive analysis possibilities, model calculations, data, reports and simulation results presented here are arranged as follows:



Glitch Working Group repository (Final report)

The ISO Glitch Working Group (GWG) was established to analyse detector glitches in the four ISO instruments, with the aim of identifying the common and differing factors between the various detector and shielding designs. This repository contains ISO shielding information, publications on the glitch phenomenon, as well as minutes of the GWG meetings.



The ESA-sponsored interactive orbit generator and tool for environmental effects evaluation. This user-friendly package is recommended to be used for separate detailed analyses.


Cosmic ray environment

CREME96 model predictions translated to differential and integral spectra of protons and the heavy cosmic ray ions He, C, N, O, Si, Ca, and Fe for the ISO-type orbit during solar minimum. Cosmic proton and electron data from the IMP-8 spacecraft.


Trapped particle environment

Fluxes from the static AE8 and AP8 trapped electron and proton models for the ISO orbit in solar maximum and minimum conditions, together with particle data in various altitudes and energy ranges from the REM experiment and from the GOES and LANL spacecraft. Absorbed radiation dose data from the ISOCAM RadFET.


Solar flare particle environment

1-100 MeV proton integral fluxes from GOES-9, a movie of the corresponding proton spectrum as a function of time by H. Evans (ESTEC), and plots of neutron monitor data during the large solar event of 3-9 November 1997.


Geomagnetic indices

The geomagnetic indices Kp, C9, and DST in the years 1995-1997 from the NSSDC OMNIWeb server.


Spacecraft data

Access the extensive index of various spacecraft data at NSSCD.


Neutron monitor data

Plots of the Oulu and Thule high- latitude (vertical cut-off rigidity < 1GV) neutron monitor data in the years 1995-1996 from the NOAA/NASA SPIDR system.


ISO particle transport analysis

Ray-tracing simulations of the ISOCAM LW CCD detector using the GEANT-4 Monte Carlo code.


ISO glitch statistics

The mean numbers and intensities of pixels affected in ISOCAM glitches over two years, diagrams by J. Sorensen (ESTEC).


Radiation-related ISO analyses and reports

The ISOCAM Glitch Library, detailed glitch rate and type analysis of the ISOCAM instrument by Arnaud Claret and Herve Dzitko (CEA-Saclay). Includes calculations on the effects of d-rays and other secondary particles, as well as contribution of a-particles from the Thorium coating of the instrument lens system.

The ISO orbit with respect to the Earth's magnetosphere for a number of revolutions, calculated by Ana Heras (Vilspa)

ISO Real-time revolution report for Rev. 722 by Astrid Heske (Vilspa)

A short assessment of the impact of Rev. 722 Solar Flare on ISOCAM by Marc Sauvage (Vilspa)

Report on Rev. 722 radiation effects on ISOPHOT by Hector Castaneda et al. (Vilspa)

Report on the impact of the solar flare on the LWS instrument by Damien Texier (Vilspa)

Assesment of the impact on SWS observations of the intense proton event on November 6th 1997 by Ana Heras (Vilspa)

ISO star tracker response to radiation, information provided by Juergen Faelker (Vilspa)

Radiation-induced degradation of the ISO solar cells, analysis by H. Evans (ESTEC)

Radiation Effects on ISOCAM on board ISO by A. Claret, H. Dzitko and J.J. Engelmann, CEA/Saclay, France


For questions, comments, and further information, contact P. Nieminen at ESA/ESTEC.