Abstract Details

Name: Prashant Kumar
Affiliation: Physical Research Laboratory
Conference ID: ASI2017_1328
Title : Solar Wind Ion Spectrometer (SWIS) on-board Aditya-L1 Mission
Authors and Co-Authors : Prashant Kumar (PRL,Ahmedabad), Arpit R Patel (PRL,Ahmedabad), Hitesh L Adalja (PRL,Ahmedabad), Pranav R Adhyaru (PRL,Ahmedabad), S B Banerjee (PRL,Ahmedabad), M Shanmugam (PRL,Ahmedabad), Tinkal Ladiya (PRL,Ahmedabad), M B Dadhania (PRL,Ahmedabad), K P Subramanian (PRL,Ahmedabad), Bhas Bapat (IISER, Pune), P Janardhan (PRL,Ahmedabad), D Chakrabarty (PRL,Ahmedabad), Aveek Sarkar (PRL,Ahmedabad), Santosh V Vadawale (PRL,Ahmedabad), S K Goyal (PRL,Ahmedabad), Neeraj K Tiwari (PRL,Ahmedabad), A K Hait (SAC, Ahmedabad), R Bhavsar (SAC, Ahmedabad), M Chauhan (SAC, Ahmedabad)
Abstract Type : Oral
Abstract Category : Instrumentation and Techniques
Abstract : ASPEX is one of the six payloads selected for the upcoming Aditya-L1 mission. The objective of this payload is to carry out systematic and continuous in-situ measurement of particle fluxes over an energy range from 100 eV to 5 MeV from the L1 point of the Sun-Earth system. SWIS is a sub-system of this payload and is primarily meant to measure ions in the energy range of 100 eV—20 keV. The main scientific objectives of SWIS are to understand the origin of supra-thermal ions, to study thermal anisotropy, to detect arrival of CME’s at L1 by providing a "compositional flag" and to understand the solar wind turbulence. To accomplish the above stated objectives, observational requirement demands FOV coverage of 2π in the plane of ecliptic as well as across this plane. To suit this requirement, two top hat energy analysers (THA) will be used in SWIS. The first analyser (THA-1) will scan ions coming in the ecliptic plane and has the capability to measure angular, energy and mass distributions simultaneously in the required energy range. In this analyser, a magnetic mass separator, consisting of 16 thin permanent magnets, is used to differentiate masses of ions arriving on the detector. The second analyser (THA-2) has the acceptance plane perpendicular to the ecliptic. THA-2 only measures the energy and angular distribution of the incoming ions. The detector in both these analysers consists of chevron MCP pair followed by a position sensitive detector. The design parameters for electrostatic part (ESA) in both the analysers were optimised based on ion trajectory simulations performed in SIMION. The instrument response for both the analysers was studied and an energy resolution of 10% is obtained. An in-house developed MATLAB code was used to understand the field pattern of the magnetic mass analyser (MMA). This helped in deciding various design parameters for the MMA and also in estimating magnetic field leakages due to MMA. To verify the simulation results, experiments on a similar instrument were conducted in lab using a Nier type ion source and position sensitive anode made from PCB with metallic tracks. The analyser response and the magnetic deflection values were obtained for ions of different mass which includes H2+, He+, Ar+ and Ne+ at 2keV energy. These values show good agreement with the simulated ones. Presently, the payload is at PDR stage and an engineering model is expected by mid of 2017.