BRIEF DESCRIPTION Cosmic Ray Particles (Principal Investigator: Kunow) HELIOS-A and -B spacecrafts were the pair of deep space probes developed by the Federal Republic of Germany (FRG) in a cooperative program with NASA. The purpose of the mission was to make pioneering measurments of the interplanetary medium from the vicinity of the earth's orbit to 0.3 AU. The objective of experiment (E6) was to study high-energy, charged, cosmic-ray particles of solar, planetary, and galactic origin in interplanetary space. Protons and alpha particles with eneries >1.3 MeV/nucleon, and electrons >0.3 MeV were measured within interplanetary space over the range from 0.3 to 1.0 AU. The instrument, a particle telescope with 55-deg field of view, consisted of five semiconductor detectors, one sapphire Cherenkov counter, and one scintillation counter, all enclosed by an anticoincidence cylinder. The telescope was calibrated prior to launch using radioactive sources, particle acceletors, and ground-level muons. It measured protons and alpha particles in six channels (1.3-3.3, 3.3-13, 13-27, 27-37, 37-45, and >45 MeV/nucleon) and electrons in five energy channels (0.3-0.8, 0.8-2, 2-3, 3-4, and >4 MeV). For more detail see pp.253-257 of Raumfahrtforschung, v.19, n. 5, 1975. The h-a-cr*.dat and h-b-cr*.dat files contains hourly averaged fluxes of electrons, protons and alpha particles in the MeV ranges. The files were written in ASCII-codes. Each record contains 10 hourly averages. The differential fluxes (particles/sq.m, s, sr, MeV) cover, in several bands, the energy range 0.3-2.0 MeV for electrons, 4.0-51 MeV for protons, and 2.0-48 MeV for alpha particles. Also provided are the integral fluxes of alphas above 48 MeV, and protons above 51 MeV. For some of the energy channels, the standard deviations of the averages are also provided. Each file is preceded by a header record, providing the start and stop times of the data in the file. For h-a-cr*.dat files: Time Coverage: 1974/12/11 - 1983/12/31 For h-b-cr*.dat files: Time Coverage: 1976/01/16 - 1980/03/08 File Header Block Format: Word Data Type Format Contents _____________________________________________________________________________ 1-3 Literal 3A2 HELIOS 4 Integer I2 S/C number (1 or 2) 5-20 Literal 16A2 _EXPERIMENT_6_UNIVERSITAET_KIEL_ 21-24 Literal 4A2 START:__ 25-26 Integer I4 Year (e.g. 1976) 27-28 Integer I4 Day of year (e.g. _345) 29-30 Integer I4 Hour (e.g. __23) 31-32 Integer I4 Minute (e.g. __12) 33-36 Literal 4A2 STOP:___ 37-38 Integer I4 Year (e.g. 1976) 39-40 Integer I4 Day of year (e.g. _346) 41-42 Integer I4 Hour (e.g. __23) 43-44 Integer I4 Minute (e.g. __10) 45-51 Literal 7A2 VERSION:______ 52 Integer I2 Program Version (e.g. _1) ________________________________________________________________________ Science Data Block Format: Word Data Type Format Contents _____________________________________________________________________________ 1-2 Integer I4 Start time of averaging interval: year 3-4 " " day of year 5-6 " " hour 7-8 " " minute 9-10 " " Stop time of averaging interval: year 11-12 " " day of year 13-14 " " hour 15-16 " " minute 17-22 Real E12.5 Count rate P 4-13 protons 23-28 " " Standard deviation P 4-13 " 29-34 " " " P 13-27 " 35-40 " " " P 13-27 " 41-46 " " " P 27-37 " 47-52 " " " P 27-37 " 53-58 " " " P 37-51 " 59-64 " " " P 37-51 " 65-70 " " " P >51 " 71-76 " " " P >51 " 77-82 " " " A 2-4 alpha particles 83-88 " " " A 2-4 " 89-94 " " " A 4-13 " 95-100 " " " A 4-13 " 101-106 " " " A 13-27 " 107-112 " " " A 13-27 " 113-118 " " " A 27-37 " 119-124 " " " A 27-37 " 125-130 " " " A 37-48 " 131-136 " " " A 37-48 " 137-142 " " " A >48 " 143-148 " " " A >48 " 149-154 " " " E 0.3-0.8 electrons 155-160 " " " E 0.3-0.8 " 161-166 " " " E 0.8-2 " 167-172 " " " E 0.8-2 " 173-1720 9 repetitions of words 1-172 _____________________________________________________________________________ The acronyms for the rate channels are composed of a letter and an indication of the energy range in MeV/nucleon for protons and alpha particles respectively. MeV for electrons. The counting rates are given as particles/m^2 sec sr MeV/N, except for the integral channels P>51 and A>48 which are given as particles/ m^2 sec sr. Note: 1. Negative rates (-0.99999E+04) indicate missing or invalid data. 2. The energy boundaries for the electron channels E 0.2-0.8 and E 0.8-2 are only rough estimates.