urn:nasa:pds:context:instrument:vega1.pm1 1.0 1.11.0.0 Product_Context urn:nasa:pds:context:instrument:pm1.vega1 2021-02-24 1.0 Changed inst LIDs from u:n:p:c:i:instID.scID to u:n:p:c:i:scID.instID And per "Guide toPDS4 Context Products" v1.7, changed all lidvid_reference to lid_reference urn:nasa:pds:context:instrument_host:spacecraft.vega1 instrument_to_instrument_host Apathy, I., A.P. Remizov, K.I. Gringauz, V.M. Balebanov, I. Szemerey, S. Szendro, T. Gombosi, I.N. Klimenko, M.I. Verigin, E. Keppler, and A.K. Richter, Plazmag-1 Experiment, ESA SP-250, Vol I, 65-70, 1986. reference.APATHYETAL1986 Reinhard, R and B. Battrick (eds), 'Space Missions to Halley's Comet', European Space Agency ESA SP-1066, ESA Pub Div, Moordwijk, Netherlands, 1986. reference.ESA-SP1066 Galeev, A.A., K.I. Gringauz, S.I. Klimov, A.P. Remizov, R.Z. Sagdeev, S.P. Savin, A.Yu. Sokolov, M.I. Verigin, K. Szego, M. Tatrallyay, R. Grard, Ye.G. Yeroshenko, M.J. Mogilevsky, W. Riedler, and K. Schwingenschuh, Physical Processes in the Vicinity of the Cometopause Interpreted on the Basis of Plasma, Magnetic Field and Plasma Wave Data Measured On Board the Vega-2 Spacecraft, Proceedings of the Symposium on the Diversity and Similarity of Comets, Brussels 1987, ESA SP-278, 83-87, 1987. reference.GALEEVETAL1987 Galeev, A.A., K.I. Gringauz, S.I. Klimov, A.P. Remizov, R.Z. Sagdeev, S.P. Savin, A.Yu. Sokolov, M.I. Verigin, K. Szego, M. Tatrallyay, R. Grard, Ye.G. Yeroshenko, M.J. Mogilevsky, W. Riedler, and K. Schwingenschuh, Physical Processes in the Vicinity of the Cometopause Interpreted on the Basis of Plasma, Magnetic Field and Plasma Wave Data Measured On Board the Vega-2 Spacecraft, Journal of Geophysical Research, 93, 7527-31, 1988. reference.GALEEVETAL1988 Gringauz, K.I., I. Apathy, L.I. Denshchikova, T. Gombosi, E. Keppler, I.N. Klimenko, A.P. Remizov, A.K. Richter, G.A. Skuridin, A. Somogyi, L. Szabo, I. Szemerey, S. Szendro, M.I. Verigin, G.A. Vladimirova, and G.I. Volkov, The Vega Probe Instrument Package for Measuring Charged Particles with Energies Less Than 25 keV, Cometary Exploration III, Gombosi, T.I. (ed.), 333-349, 1983. reference.GRINGAUZETAL1983 Gringauz, K.I., I. Klimenko, A. Remizov, M.I. Verigin, G. Vladimirova, I. Apathy, K. Szego, I. Szemerey, S. Szendro, M. Tatrallyay, E. Keppler, and A. Richter, The Vega Plasmag-1 Experiment: Description and First Experimental Results, Field, Particle and Wave Experiments on Cometary Missions, Schwingenschuh, K. and W. Riedler (eds.), 157-171, 1985. reference.GRINGAUZETAL1985 Gringauz, K.I., A.P. Remizov, M.I. Verigin, A.K. Richter, M. Tatrallyay, K. Szego, I.N. Klimenko, I. Apathy, T.I. Gombosi, and I. Szemerey, Electron Component of the Plasma Around Halley's Comet Measured by the Electrostatic Electron Analyzer of PLASMAG-1 On Board Vega-2, ESA SP-250, Vol I, 195-198, 1986. reference.GRINGAUZETAL1986A Gringauz, K.I., I.N. Klimenko, A.P. Remizov, M.I. Verigin, G.A. Vladimirova, I. Apathy, K. Szego, I. Szemerey, S. Szendro, M. Tatrallyay, E. Keppler, and A.K. Richter, The Vega PLASMAG-1 Experiment: Description and First Experimental Results, Field, Particle and Wave Experiments on Cometary Missions, Austrian Academy of Sciences, Proceedings of International Workshop, Graz, Austria 1985, 203-216, 1986. reference.GRINGAUZETAL1986B Gringauz, K.I., M.I. Verigin, A.K. Richter, T.I. Gombosi, K. Szego, M. Tatrallyay, A.P. Remizov, and I. Apathy, Cometary Plasma Region in the Coma of Comet Halley: Vega-2 Measurements, ESA SP-250, Vol I, 93-98, 1986. reference.GRINGAUZETAL1986C Gringauz, K.I., T.I. Gombosi, A.P. Remizov, I. Apathy, I. Szemerey, M.I. Verigin, L.I. Denchikova, A.V. Dyachkov, E. Keppler, I.N. Klimenko, A.K. Richter, A.J. Somogyi, K. Szego, S. Szendro, M. Tatrallyay, A. Varga, and G.A. Vladimirova, First In Situ Plasma and Neutral Gas Measurements at Comet Halley: Initial Vega Results, Nature, 321, 282-285, 1986. reference.GRINGAUZETAL1986D Gringauz, K.I., T.I. Gombosi, A.P. Remizov, I. Apathy, I. Szemerey, M.I. Verigin, L.I. Denchikova, A.V. Dyachkov, E. Keppler, I.N. Klimenko, A.K. Richter, A.J. Somogyi, K. Szego, S. Szendro, M. Tatrallyay, A. Varga, and G.A. Vladimirova, First Results of Plasma and Neutral Gas Measurements from Vega-1/2 Near Comet Halley, Advances of Space Research, 5, No. 12, 165-174, 1986. reference.GRINGAUZETAL1986E Gringauz, K.I., T.I. Gombosi, M. Tatrallyay, M.I. Verigin, A.P. Remizov, A.K. Richter, I. Apathy, I. Szemerey, A.V. Dyachkov, O.V. Balakina, and A.F. Nagy, Detectionof a New 'Chemical' Boundary at Comet Halley, Geophysical Research Letters, 13, 613-616, 1986. reference.GRINGAUZETAL1986F Gringauz, K.I., A.P. Remizov, M.I. Verigin, A.K. Richter, M. Tatrallyay, K. Szego, I.N. Klimenko, I. Apathy, T.I. Gombosi, and T. Szemerey, Analysis of the Electron Measurement from the PLASMAG-1 Experimet On Board Vega-2 in the Vicinity of Comet P/Halley, Astronomy and Astrophysics, 187, 287-289, 1987. reference.GRINGAUZETAL1987A Gringauz, K.I., A.P. Remizov, M.I. Verigin, A.K. Richter, M. Tatrallyay, K. Szego, I.N. Klimenko, I. Apathy, T.I. Gombosi, and I. Szemerey, Electron Component of Plasma in Vicinity of Comet Halley According to Measurement from the Electron Electrostatic Analyzer of the 'Plazmag-1' Complex on the Vega-2 Spacecraft, Cosmic Research, 25, 729-733, 1987. reference.GRINGAUZETAL1987B Gringauz, K.I., M.I. Verigin, A.K. Richter, T.I. Gombosi, K. Szego, M. Tatrallyay, A.P. Remizov, and I. Apathy, Quasi Periodic Features and the Radial Distribution of Cometary Ions in the Cometary Plasma Region of Comet P/Halley, Astronomy and Astrophysics, 187, 191-194, 1987. reference.GRINGAUZETAL1987C Verigin, M.I., K.I. Gringauz, A.K. Richter, T.I. Gombosi, A.P. Remizov, K. Szego, I. Apathy, I. Szemerey, M. Tatrallyay, and L.A. Lezhen, Characteristic Features of the Cometosheath of Comet Halley: Vega-1 and Vega-2 Observations, ESA SP-250, Vol I, 169-174, 1986. reference.VERIGINETAL1986 Verigin, M.I., K.I. Gringauz, A.K. Richter, T.I. Gombosi, A.P. Remizov, K. Szego, I. Apathy, I. Szemerey, M. Tatrallyay, and L.A. Lezhen, Plasma Properties from the Upstream Region to the Cometopause of Comet P/Halley: Vega Observations, Astronomy and Astrophysics, 187, 121-124, 1987. reference.VERIGINETAL1987A Verigin, M.I., K.I. Gringauz, A.K. Richter, T.I. Gombosi, A.P. Remizov, K. Szego, I. Apathy, I. Szemerey, M. Tatrallyay, and L.A. Lezhen, Plasma Transitional Region of Comet Halley (Cometosheath): Vega-1 and Vega-2 Data, Cosmic Research, 25, 712-718, 1987. reference.VERIGINETAL1987B PLASMA ENERGY ANALYZER Spectrometer not applicable not applicable Instrument Overview =================== The instrument includes six detectors: two ion analysers, one electron analyser, two collectors which measure the integral plasma ion flux, and one sensor which monitors the integral electron current produced from its surface by photon and particle bom- bardment. The ion detectors are designed for the study of the energy distribution of the solar and cometary particles, and not for the investigation of their three- dimensional velocity distribution. Each sensor consists of a quadripolar electrical lens (2), a hemispherical plate analyser (3) and a channeltron (4). The energy spectrum is swept once per second by stepping the bias voltage U(A) applied between the plates. The detector oriented towards the Sun has a conical of view (1) with a half angle of 15deg, wide enough to detect the solar wind both upstream and downstream of the cometary bow shock. The ion detector oriented along the spacecraft-comet velocity vector is intended for operation in the innermost part of the coma, where the cometary ions are expected to have thermal velocities that are negligible with respect to their relative drift velocity of 78 km/s. This system can therefore be used as a mass spectrometer in the range 1-110 amu with a resolution m/delta m = 20; the minimum measurable ion density is 10**-3/cm**3. The electron analyser has an aperture of 0.03 cm**2, an angular resolu- tion of +/-2.5deg, and an energy resolution of +/-5%; its geometrical factor is 10**-5 E (keV) (cm**2.sr.keV). Its aperture is oriented perpendicular to the Sun and relative- velocity directions in order to eliminate interferences generated by photon and particle impacts. The energy spectrum is scanned by applying a series of logarithmically distributed voltage steps U(A) to a cylindrical deflection unit (1). The entrance of the instrument is controlled by a collimator (2) and a grid (3); the detector is a channeltron (4). The integral detector which measures the solar-wind ions consists of a collimator, a number of grids to limit the flux of photoelectrons, and a collector. A potential of +3500 V is periodically applied to one of the grids in order to stop the ion flux and evaluate the interference background. The aperture has an area of 5 cm**2 and the dynamic range of the measurements extends from +/- 10**-11 A to +/- 3x10**-9 A. The integral detector, which is aligned with the relative-velocity vector, has similar features, but the electrodes are configured such that the incoming dust par- ticles and neutral molecules can only impact on the first diaphragm and on the collec- tor. By biasing the electrodes differently, in an alternative configuration, it is possible to discriminate between the cometary ions and the charged particles produced by various impact ionisation processes. The impact plasma monitor is a gold electrode, biased at a fixed potential of -17 V, which measures the integral flux of electrons emitted by the impact of neutral gas, dust particles and photons, in the range 10**-10-3x10**-5 A. The characteristics of the various detectors are summarised in the table below. --------------------------------------------------------------------- Table. Plasma Energy Analyser characteristics 1. Channeltron detector Particles Solar ions Cometary ions Electrons --------------------------------------------------------------------- Pointing direction Sun Relative Perpendicular velocity to Sun and relative velocity Energy range 50 eV-3.5 keV 15 eV-3.5 keV 3 eV-10 keV 3 eV-30 eV Points per spectrum 60 120 30 Time resolution 1 s 1 s 1 s Aterture 15deg half cone 15deg half cone 5deg X 10deg --------------------------------------------------------------------- 2. Electrode detector Particles Solar ions Cometary ions Emitted Electrons ----------------------------------------------------------------------- Pointing direction Sun Relative Relative velocity velocity Energy range Integral Integral Integral Points per spectrum 1 1 1 Time resolution 0.125 s 0.125 s 1 s Aterture 45deg half cone 8deg half cone 90deg half cone Instrument summary The PLASMAG-1 instument package included six different sensors: A0 plasma impact detector for measuring neutral particle flux, (manufactured by R. Grard, ESA/ESTEC, Noordwijk, The Netherlands) A1 Faraday cup for measuring integral ion flux from solar direction, A2 Faraday cup for measuring integral ion flux and neutral particles from ram direction, A3 spherical electrostatic analyzer for measuring ions from ram direction in the energy range of 15 eV - 3.6 keV in 120 logarithmically spaced channels, A4 spherical electrostatic analyzer for measuring ions from solar direction in the energy range of 60 eV - 30 keV in 60 logarithmically spaced channels, A5 cylindrical electrostatic analyzer for measuring ions perpendicular to the ecliptic plane in the energy range of 2 eV - 10 keV in 30 logarithmically spaced channels. Scientific objectives The electrostatic ion analyzers A3 and A4 were designed to study the change of the energy distribution of the solar wind and cometary ions as a function of the distance from the nucleus. The detector oriented in the ram direction could determine the mass distribution of cometary ions close to the nucleus with a resolution of m/dm=20-25. The ram Faraday cup A2 had four modes of operation. Two of these provided information on the neutral particle flow from the comet. For further informations on instrument overview and scientific objectives (also first results) see the following papers: 1) Gringauz et al., The Vega probe instrument for measuring charged particles with energies less than 25 keV, in Cometary exploration Vol. III., ed. by T.I. Gombosi, pp. 333-350, Central Res.Inst. Physics, Budapest, 1982. 2) Gringauz et al., First in situ plasma and neutral gas measurements at Comet Halley, Nature 321, 282-285, 1986. 3) Apathy et al., Plazmag-1 experiment, in Exploration of Halley's Comet, ESA SP-250, Vol. I., ed. by B. Battrick, E.J. Rolfe, and R. Reinhard, pp. 65-70, Paris, 1986. Operational considerations The sensitivity of the electron analyzer A5 was very low. Detectors A3 and A5 of Vega-1 were fatally damaged during the cruise phase.Detector A3 of Vega-2 was fatally damaged 2.5 min before closest approach. The channeltrons of A3 were saturating at higher count rates. Calibration description The sensors were calibrated at the Max-Planck-Institut for Aeronomy in Katlenburg/Lindau, Germany. The viewing angle and energy resolution of the electrostatic analyzers were determined in vacuum chamber using monoenergetic ion and electron beams, respectively. (For further details see reference #3 above.) The spectrometers used Soviet-made channeltrons as particle detectors. An in-flight calibration was performed every day to select the optimum voltage for the channeltrons. A post-launch calibration was performed in order to correct the saturating count rates of detector A3 of Vega-2 using the integral fluxes provided by the ram Faraday cup A2. Principal investigator: K.I. Gringauz, Space Res. Inst., Moscow, Co-principal investigator: T.I. Gombosi, Cent. Res. Inst. Physics, Budapest, Co-investigators: A.P. Remizov, M.I. Verigin, L.I. Denchikova, A.V. Dyachkov, I.N. Klimenko, G.A, Vladimirova, Space Res. Inst., Moscow I. Apathy, T. Szemerey, S. Szendro, A.J. Somogyi, K. Szego, M. Tatrallyay, A. Varga, Cent. Res. Inst. Physics, Budapest, E. Keppler, Max-Planck-Inst. Aeronomy, Lindau, Germany. Instrument section Field of view of the detectors: A1: 90x90 deg (centered on solar direction), A2: 26x26 deg (centered on ram direction), A3: 32x12 deg (centered on ram direction), A4: 36x32 deg (centered on solar direction), A5: 7x7 deg (perpendicular to ecliptic plane). Effective apperture: A1: 1.6 cm**2 A2: 0.93 cm**2 A3: 0.0193 cm**2 A4: 0.00455 cm**2 A5: 0.0036 cm**2 Energy resolution: A3: 3.2 % A4: 3.85% A5: 7.5 % One complete spectrum was taken by A3, A4, and A5 in every second during the BRL (high telemery rate) seance. Sampling times for each energy channel: A3: 0.005 sec A4: 0.005 sec A5: 0.021 sec During the cruise phase data were recorded by an on-board magnetometer at lower telemetry rate.