####Pioneer 11 Cosmic Ray Telescope Calibrated Bundle readme

***

#####Brief Bundle Description

Pioneer 11 Cosmic Ray Telescope Calibrated Bundle contains Cosmic-ray
telescope (CRT) data from the Jupiter and Saturn encounter period. The Bundle 
provides both 15.0 minute flux averages from 18 electron, proton, heavy ion channels
and full six-hour average interplanetary cruise count rate and flux data.

Bundle Organization:

* Pioneer 11 CRT Calibrated 15 Minute Data Collections
  
  *urn:nasa:pds:p11-crt-cal:data-15min-jup*
  *urn:nasa:pds:p11-crt-cal:data-15min-sat*

* Pioneer 11 CRT Calibrated 6 Hour Data Collection
  
  *urn:nasa:pds:p11-crt-cal:data-6hr*


These data were originally archived in the following PDS3 data sets:

PDS3 P11-J-CRT-4-SUMM-FLUX-15MIN-V1.0 

* https://doi.org/10.17189/1519779

PDS3 P11-S-CRT-4-SUMM-FLUX-15MIN-V1.0 

* https://doi.org/10.17189/1519795

PDS4 documentation is all LBLX. There is an LBLX label for every product in the
archive.

***

#####Pioneer 11 CRT Calibrated 15 Minute Data Collections

This collection contains Pioneer 11 Cosmic-ray telescope (CRT) data from the
Jupiter and Saturn encounter period, covering 1974-11-26 to 1979-09-03. The collections
provides 15.0 minute flux averages from 18 electron, proton, and heavy ion
channels.

***

#####Pioneer 11 CRT Calibrated 6 Hour Data Collection

This collection contains full six-hour average interplanetary cruise count
rate and flux data in ASCII format from the Pioneer 11 Cosmic Ray Telescope
(CRT) experiment.

***

#####Instrument Overview

The cosmic ray telescope used for this experiment was also designed
to monitor solar and galactic cosmic rays and track the twisting
high energy particles from the Sun. The instrument can determine
which of the nuclei of the ten lightest elements make up these
cosmic ray particles. Before saturation by radiation, the cosmic ray
telescope measured high energy particles in Jupiter's radiation
belts.

The instrument consists of three, three-element, solid-state
telescopes. The high energy telescope measures the flux of protons
between 56 and 800 MeV. The medium energy telescope measures protons
with energies between 3 and 22 MeV, and identifies the ten elements
from hydrogen to neon. The low energy telescope measures the flux of
electrons between .05 and 1 MeV, and of protons between .05 and 20 MeV.

#####Instrument Attributes:

The Goddard Space Flight Center(GSFC)/ University of New
Hampshire Cosmic Ray Telescope(CRT) experiment on Pioneer-10 and -11 consists
of two types of solid state detector telescopes, the High Energy Tele-scope
(HET) and two Low Energy dE/dx vs. E Telescopes (LET I and II). These are
designed to complement each other and to cover a broad range in energy,
intensity, and charge spectra. Charged particle spectra and angular
distributions are measured over energy intervals as follows:

| Particle Component           | Energy Range            |
|------------------------------|-------------------------|
| Galactic cosmic ray protons  | 4.5 - 800 MeV           |
| Solar protons                | .05- 800 MeV            |
| Galactic cosmic ray helium   | 4.5 - 600 MeV/nucleon   |
| Solar helium                 | 1.0 - 600 MeV/nucleon   |
| He3/He4, D/H                 | 4.5 -  50 MeV/nucleon   |
| Galactic and Solar electrons | .05- 5.0 MeV            |
| Li,Be,B,C,N,O,F,Ne and       |                         |
| their isotopic composition   | 6 MeV/nuc - 200 MeV/nuc |
|------------------------------|-------------------------|
| Angular Distribution Studies                           |
| hydrogen                     | .05- 120 MeV            |
| helium                       | 4.5 - 120 MeV/nucleon   |
| electrons                    | .05- 5 MeV              |
|------------------------------|-------------------------|
| Geometrical Factors                                    |
| HET                          | 0.220 cm2-ster.         |
| LET-I                        | 0.155 cm2-ster.         |
| LET-II                       | 0.015 cm2-ster.         |

High Energy Telescope:  The HET consists of a multi-element array of solid
state detectors. Two of these elements are single lithium drift detectors, 300
mm2 area and 2.5 mm thick.  The third element is a stacked arrangement of five
850 mm2, 2.5 mm thick lithium drift detectors.  For particles which come to
rest within this stack (20 - 50 MeV/ nucleon) three measurements are made -
energy loss (dE/dx), total energy, and range. For particles which penetrate
completely through the stack of solid state detectors three separate dE/dx
measurements are made. This multiparameter analysis reduces the back-ground
level of spurious events to a negligible level. Charge resolution for
penetrating particles is possible up to about 200 MeV/nucleon. It is estimated
that the absolute uncertainty in the helium flux is about 12% at 400 MeV and
about 7% at energies below 200 MeV.

Low Energy Telescope I.  This detector was designed to measure low-energy solar
flare particles in the interplanetary space and trapped particles in the Jovian
magnetosphere.  Its small geometry factor (1.5E-02 cm**2.sr) allows measurement
of fluxes as high as 5.0E+05/(cm**2.s.sr). The LET I is a double dE/dx vs. E
solid state detector.  Two thin (100 microns thickness and 100mm2 area) surface
barrier detectors serve to define the geometry and to provide a double dE/dx
measurement. A thick (2.5mm thickness and 300mm2 area) lithium drift detector
provides a total energy measurement. LET I covers the energy range 3 to 22
MeV/nucleon with charge resolution from Z=1 to 8. Angular distributions are
available for this data.

Low Energy Telescope II.  Two solid state detectors, one thin (50 microns thick
and 50mm2 area) and one thick (2.5mm thick and 50mm2 area) are used
individually and in coincidence as total absorption spectrometers. A third
detector operating in an anticoincidence mode insures that only stopping
particles are analyzed. The thin detector responds to protons between 50 keV
and 3 MeV and electrons between 50 and 150 keV. The thick detector is sensitive
to protons between 3 and 20 MeV and electrons between 150 keV and 1 MeV, and in
these latter energy intervals an unambiguous separation of protons and
electrons is possible.

#####Bundle Parameters:

6 hour averages of the following fluxes, plus statistical errors
    units of particles/(cm**2.sec.ster.MeV/nuc) as follows:


The initial data from Pioneer 10 and 11 following their launch on March 2,1972
and April 6, 1973 indicated that all three cosmic ray telescopes and their
associated electronics in each of the CRT experiments were functioning in a
normal fashion and there was no evidence of a malfunction in any part of the
system.  In fact, the charge, mass and energy resolution and the very low
background levels in the 3 parameter analysis were significantly better than
our pre-launch expectations.

This excellent performance made possible the discovery of anomalous oxygen and
nitrogen in the low energy portion of the galactic cosmic ray spectra, Jovian
electrons in interplanetary space and the detailed study of the charge
composition of the August 1972 solar cosmic ray events.  The excellent energy
resolution proved to be a necessity when the measured cosmic ray gradients were
found to be almost an order of magnitude smaller than predicted by the theories
of cosmic ray modulation existing at that time.  Furthermore, these particle
gradients are decreasing with increasing heliocentric distance. The long-term
gain stability of both the HET and LET telescopes on P10/11 has been remarkable
with no observable shift in the end-points of the stopping particle
distribution.

During the 19.8 years since the launch of P-10 there developed 4 electronic
anomalies of which only one has impaired the quality of the cosmic ray data.
On P-11 there was one detector problem which extended over significant periods
of time (months to years) and which was followed by a return to normal
operation.

***

Users of these data are encouraged to acknowledge both the PDS and the
principal investigators of the instruments whose data is used in analysis
in all publications.

For more information, refer to the document:

DATA PROCESSING AND PROGRAMMERS GUIDE FOR THE PIONEER-10 AND -11 COSMIC RAY
EXPERIMENTS, VOL. 2 CSC/TM-81/6203, March 1982

and the document:

D.E.Stillwell, R.M.Joyce, B.J.Teegarden, J.H.Trainor, G.Streeter, and
J.Bernstein, "The Pioneer-10/-11 and Helios A/B Cosmic Ray Instruments", ISEE
Transactions on Nuclear Science, Vol. NS-22, February 1975, pp. 570-573


***

#####Contacts

For questions or problems regarding this archive, please contact the PDS/PPI
PDS operator:

  Email             pds_operator@igpp.ucla.edu