| DATA_SET_DESCRIPTION |
Data Set Overview
=================
This data set consists of particle flux data and their associated
statistic errors recorded by the Cosmic Ray Telescope subsystems
onboard the Pioneer 11 spacecraft, during the Saturn encounter
period. Data are provided in 4 files and 15 flux channels from
the High Energy Telescope (HET), Low Energy Telescope I (LET-I),
and Low Energy Telescope II (LET-II) subsystems. Each channel
is defined either by a single detector, or in most of the cases,
a multiple detector coincidence logic, to supply three particle
types: electrons, protons, protons and heavy ions.
In the following rate/flux channel definitions, detectors in HET
are identified by A, B, C1, C2, C3, that of LET-I subsystem, by
D1, D2, E, F, and ones of LET-II subsystem, by S1, S2, S3, S2(A).
Detector S2(A) is an annular guard detector in LET-II. The
subscript in parentheses of a detector identifier refers to the
trigger threshold on that detector. Several detectors defining
a rate/flux channel are in coincidence unless the symbol '^'
preceding the detector identifier indicating that detector is
in anti-coincidence.
(1) A2 Rate (Saturn only) gives the counting rate in a 2.5 mm
thick Si detector with an area of 3.0 cm**2. Since the
threshold is set at 2.01 MeV, it responds primarily to
energetic electrons; however, the effective solid angle
and detection efficiency are not well known. This rate
is given for Saturn because the more desirable coincidence
rates suffered from excessive accidentals. The rate ID
is A2.
(2) A1.^A2.B.^C1 Rate (Jupiter only) gives the flux of electrons
with a range between 2.5 and 5.0 mm of Si which deposit less
than 2 MeV in the front detector. The electron energy falls
into the range of about 1.8 to 3.2 MeV. The rate ID is
A1.^A2.B.^C1.
(3) A1.^A2.B.C1.^C2 Rate (Jupiter only) gives the electron flux
with a range of 5 to 10 mm Si; the approximate energy range
of 3.2 to 5.1 MeV. The rate ID is A1.^A2.B.C1.^C2
(4) A1.^A2.B.C1.C2.^C3 Rate (Jupiter only) gives the electron
flux with a range of 10 to 15 mm Si; the approximate electron
energies are 5.1 to 8 MeV. The rate ID is A1.^A2.B.C1.C2.^C3.
(5) ^S1.S2(5).^S2(A).^S3 Rate gives the flux of electrons in
LET-II which do not trigger the 0.145 MeV threshold in the
50 gamma front detector and trigger the 50 keV threshold
in the 2.5 mm thick second detector. The anti-coincidence
requirement with the annular guard counter S2(A) and rear
detector S3 insures that the electrons stop in S2. Our
calibrations show that the 50% efficiency points occur at
0.16 and 2.0 MeV. If the electron spectrum is hard, this
rate will also respond to bresmsstrahlung and electrons
penetrating the collimator. The latter effect made the
dominant contribution in the inner Saturnian magnetosphere;
otherwise, it is believed to be small but is difficult to
evaluate. The rate ID is ^S1.S2(5).^S2(A).^S3.
(6) ^S1.S2(6).^S2(A).^S3 Rate is equivalent to rate (5) but
with a 0.35 MeV threshold in S2, corresponding to electron
energies from 0.43 to 2.0 MeV. The rate ID is
^S1.S2(6).^S2(A).^S3.
(7) ^S1.S2(7).^S2(A).^S3 Rate is equivalent to rate (5) but
with a 0.7 MeV threshold in S2 corresponding to electron
energies from 0.8 to 2.0 MeV. The rate ID is
^S1.S2(7).^S2(A).^S3.
(8) ^S1.S2(8).^S2(A).^S3 Rate is equivalent to rate (5) but
with a 1.0 MeV threshold in S2 corresponding to electron
energies from 1.1 to 2.0 MeV. The rate ID is
^S1.S2(8).^S2(A).^S3.
(9) D1(4) Rate gives the flux of protons and ions which penetrate
a 0.53 mg/cm**2 aluminized mylar foil and deposit at least
0.60 (P10) or 0.63 (P11) MeV in detector D1 of LET-I. (This
rate is not given for the Saturn encounter because of
substantial electron contamination.) For protons, this
corresponds to energies from 0.84 to 15.1 MeV.
(10) D1(5) Rate is equivalent to rate (9), but with a threshold
in D1 of 0.95 MeV corresponding to proton energies between
1.11 and 8.1 MeV.
(11) D1(6) Rate is equivalent to rate (9), but with a threshold
in D1 of 1.45 MeV corresponding to proton energies from 1.6
to 5.1 MeV.
(12) D1(7) Rate is equivalent to rate (9), but with a threshold
energy in D1 of 2.20 (P10) or 2.05 (P11) MeV corresponding
to proton energies from 2.3 to 3.6 MeV (P10) or 2.1 to 3.8
MeV (P11) respectively.
(13) D1.D2.E2.^F Rate from LET-I gives the proton flux between
10.3 and 21 MeV (P10) and between 11 and 21 MeV (P11).
A small correction has been made for the contribution from
alphas and heavier nuclei in the same energy/nucleus range.
The rate ID is D1.D2.E2.^F - D1.D2.SIGMA(D.E4.^F).
(14) S1(1).^S2.^S2(A).^S3 Rate gives the flux of protons and
heavier ions which stop in the 50 gamma thick S1 detector
S1 and deposits energy between 0.16 and 2.6 MeV. This
corresponds to proton energies between 0.20 and 2.15 MeV
(P10) or 0.20 and 2.17 MeV (P11). Detector S1 is shielded
by only 0.12 mg/cm**2 of Al and is, therefore, relatively
sensitive to low-energy ions. At Saturn, the ion contribution
is negligible; however, it may be significant at Jupiter.
The rate ID is S1(1).^S2.^S2(A).^S3 - S1(4).^S2.^S2(A).^S3.
(15) S1(6).^S2.^S2(A).^S3 Rate is equivalent to rate (14) except
that the threshold in S1 is 0.47 (P10) or 0.5 (P11) MeV, this
corresponds to proton energies of 0.50 to 2.15 MeV (P10) or
0.53 to 2.17 MeV (P11), respectively. The rate ID is
S1(6).^S2.^S2(A).^S3 - S1(4).^S2.^S2(A).^S3.
(16) S1(2).^S2.^S2(A).^S3 Rate is equivalent to rate (14) except
that the threshold is 0.74 MeV (P10) or 0.72 MeV (P11), this
corresponds to proton energies of 0.76-2.15 MeV (P10) or
0.74-2.17 MeV (P11). The rate ID is
S1(2).^S2.^S2(A).^S3 - S1(4).^S2.^S2(A).^S3.
(17) S1(3).^S2.^S2(A).^S3 Rate is equivalent to rate (14) except
the threshold is 1.2 MeV, corresponding to proton energies
of 1.24 to 2.15 MeV (P10) and 1.24-2.17 MeV (P11). The rate
ID is S1(3).^S2.^S2(A).^S3 - S1(4).^S2.^S2(A).^S3.
(18) S1.S2(1).^S2(A).^S3 Rate gives the flux of protons between
3.13 and 14.8 MeV (P10) and 3.19 to 14.9 MeV (P11). The rate
ID is S1.S2(1).^S2(A).^S3 - S1.S2(3).^S2(A).^S3.
(19) S1.S2(2).^S2(A).^S3 Rate is equivalent to rate (18) except
for a higher threshold and covers protons from 5.65 to 14.8
MeV (P10) and 5.68 to 14.9 MeV (P11). The rate ID is
S1.S2(2).^S2(A).^S3 - S1.S2(3).^S2(A).^S3.
Data Sampling
==============
The NSSDC documentation does not contain information about what
data resolution this data set (15 minute) was averaged from.
According to Stilwell et al. [STILWELLETAL1975], the CRS data
telemetry formatting was designed to keep the rate data cycle
time between 3 and 7 minutes, if this bears any information
about the original data sampling rate.
Data Processing
===============
No detailed information of data processing is found in the NSSDC
documentation pertinent to this data set.
Data Format
============
The Pioneer 11 Cosmic Ray data during Saturn encounter were
originally written on a 9-track binary magnetic tape, recorded
at 1600 BPI, on an IBM 360 computer. There are 4 data files
covering different flux groups. Each binary file was re-formatted
into a new ASCII file. Detailed description for each file is
given as below.
P11_CRS_SAT_ENC_GRP1_15MIN.TAB contains electron flux measurements
from the High Energy Telescope (HET) and Low Energy Telescope
subsystem II (LET-II).
--------------------------------------------------------------------
Column Column Column
Name Format Description
--------------------------------------------------------------------
START_TIME A23 Start time of each averaging interval
in yyyy-mm-ddThh:mm:ss.sss
R5B_FLUX E13.6 Flux of R5B channel from HET
R5B_FLUX_UNCERTAINTY E13.6 Flux uncertainty of R5B channel
SR2E(9)_FLUX E13.6 Flux of SR2E(9) channel from LET-II
SR2E(9)_FLUX_UNCERTAINTY E13.6 Flux uncertainty of SR2E(9) channel
SR2F(9)_FLUX E13.6 Flux of SR2F(9) channel from LET-II
SR2F(9)_FLUX_UNCERTAINTY E13.6 Flux uncertainty of SR2F(9) channel
SR2G(9)_FLUX E13.6 Flux of SR2G(9) channel from LET-II
SR2G(9)_FLUX_UNCERTAINTY E13.6 Flux uncertainty of SR2G(9) channel
SR2H(9)_FLUX E13.6 Flux of SR2H(9) channel from LET-II
SR2H(9)_FLUX_UNCERTAINTY E13.6 Flux uncertainty of SR2H(9) channel
--------------------------------------------------------------------
The coincidence logic for each flux column is described as below:
Column 2 = (R5B / 1.000E+00)
R5B = A2
Column 4 = (SR2E(9) / 1.500E-02)
SR2E(9) = ^S1.S2(5).^S2(A).^S3(9)
Column 6 = (SR2F(9) / 1.500E-02)
SR2F(9) = ^S1.S2(6).^S2(A).^S3(9)
Column 8 = (SR2G(9) / 1.500E-02)
SR2G(9) = ^S1.S2(7).^S2(A).^S3(9)
Column 10 = (SR2H(9) / 1.500E-02)
SR2H(9) = ^S1.S2(8).^S2(A).^S3(9)
P11_CRS_SAT_ENC_GRP2_15MIN.TAB contains proton flux measurements
from the Low Energy Telescope subsystem subsystem I (LET-I).
--------------------------------------------------------------------
Column Column Column
Name Format Description
--------------------------------------------------------------------
START_TIME A23 Start time of each averaging
interval in yyyy-mm-ddThh:mm:ss.sss
R10E_FLUX E13.6 Flux of R10E channel from LET-I
R10E_FLUX_UNCERTAINTY E13.6 Flux uncertainty of R10E channel
R10F_FLUX E13.6 Flux of R10F channel from LET-I
R10F_FLUX_UNCERTAINTY E13.6 Flux uncertainty of R10F channel
R10G_FLUX E13.6 Flux of R10G channel from LET-I
R10G_FLUX_UNCERTAINTY E13.6 Flux uncertainty of R10G channel
R13AB_FLUX E13.6 Flux of R13AB channel from LET-I
R13AB_FLUX_UNCERTAINTY E13.6 Flux uncertainty of R13AB channel
--------------------------------------------------------------------
The coincidence logic for each flux column is described as below:
Column 2 = (R10E / 1.530E+00)
R10E = D1(5)
Column 4 = (R10F / 1.530E+00)
R10F = D1(6)
Column 6 = (R10G / 1.530E+00)
R10G = D1(7)
Column 8 = (R13A / 1.550E-01) - (R13B / 1.550E-01)
R13A = D1.D2.E2.^F
R13B = D1.D2.SIGMA-D.E4.^F
P11_CRS_SAT_ENC_GRP3_15MIN.TAB contains proton and heavy ion flux
measurements from the Low Energy Telescope subsystem subsystem II
(LET-II).
--------------------------------------------------------------------
Column Column Column
Name Format Description
--------------------------------------------------------------------
START_TIME A23 Start time of each averaging
interval in yyyy-mm-ddThh:mm:ss.sss
R15AD_FLUX E13.6 Flux of R15AD channel from LET-II
R15AD_FLUX_UNCERTAINTY E13.6 Flux uncertainty of R15AD channel
SR2BD_FLUX E13.6 Flux of SR2BD channel from LET-II
SR2BD_FLUX_UNCERTAINTY E13.6 Flux uncertainty of SR2BD channel
R15BD_FLUX E13.6 Flux of R15BD channel from LET-II
R15BD_FLUX_UNCERTAINTY E13.6 Flux uncertainty of R15BD channel
--------------------------------------------------------------------
The coincidence logic for each flux column is described as below:
Column 2 = (R15A / 1.500E-02) - (R15D / 1.500E-02)
R15A = S1(1).^S2.^S2(A).^S3
R15D = S1(4).^S2.^S2(A).^S3
Column 4 = (SR2B(9) / 1.500E-02) - (R15D / 1.500E-02)
SR2B(9) = S1(6).^S2.^S2(A).^S3(9)
R15D = S1(4).^S2.^S2(A).^S3
Column 6 = (R15B / 1.500E-02) - (R15D / 1.500E-02)
R15B = S1(2).^S2.^S2(A).^S3
R15D = S1(4).^S2.^S2(A).^S3
P11_CRS_SAT_ENC_GRP4_15MIN.TAB contains proton and heavy ion flux
measurements from the Low Energy Telescope subsystem subsystem II
(LET-II).
--------------------------------------------------------------------
Column Column Column
Name Format Description
--------------------------------------------------------------------
START_TIME A23 Start time of each averaging
interval in yyyy-mm-ddThh:mm:ss.sss
R15CD_FLUX E13.6 Flux of R15CD channel from LET-II
R15CD_FLUX_UNCERTAINTY E13.6 Flux uncertainty of R15CD channel
R16AC_FLUX E13.6 Flux of R16AC channel from LET-II
R16AC_FLUX_UNCERTAINTY E13.6 Flux uncertainty of R16AC channel
R16BC_FLUX E13.6 Flux of R16BC channel from LET-II
R16BC_FLUX_UNCERTAINTY E13.6 Flux uncertainty of R16BC channel
--------------------------------------------------------------------
The coincidence logic for each flux column is described as below:
Column 2 = (R15C / 1.500E-02) - (R15D / 1.500E-02)
R15C = S1(3).^S2.^S2(A).^S3
R15D = S1(4).^S2.^S2(A).^S3
Column 4 = (R16A / 1.500E-02) - (R16C / 1.500E-02)
R16A = S1.S2(1).^S2(A).^S3
R16C = S1.S2(3).^S2(A).^S3
Column 6 = (R16B / 1.500E-02) - (R16C / 1.500E-02)
R16B = S1.S2(2).^S2(A).^S3
R16C = S1.S2(3).^S2(A).^S3
Individual detectors in HET are identified by A, B, C1, C2,
and C3. Detectors in LET-I subsystem are identified by D1,
D2, E, and F. Detectors in LET-II subsystem are identified
by S1, S2, S3, and S2(A), the annular guard detector. The
subscript in parentheses of a detector identifier refers to
the trigger threshold on that detector. Several detectors
defining a flux channel are in coincidence unless the symbol
'^' preceding the detector identifier indicating that detector
is in anti-coincidence.
Coordinate System for Data
===========================
No coordinate system is pertinent to the particle flux data.
Ancillary Data
==============
There is no ancillary data associated with this data set.
Instrument Calibration
======================
No detailed information of instrument calibration is found in the
NSSDC documentation pertinent to this data set.
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