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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