V. Yadav, Space Physics Laboratory, Vikram Sarabhai Space Centre, vkyadavcsp@gmail.com
  N. Srivastava, Udaipur Solar Observatory, PRL, Udaipur 313004, India, nandita@prl.res.in
  S. Ghosh, Indian Institute of Geomagnetism (IIG), New Panvel, Navi Mumbai 410218, India, sukti@iigs.iigm.res.in
  S. P.T., ISRO Satellite Centre (ISAC), Vimanpura, Bengaluru 560017, India, srikar@isac.gov.in
  S. K., Laboratory for Electro-Optical Systems (LEOS), Peenya, Bengaluru 560058, India, jslakshmi@leos.gov.in

The Aditya-L1 mission is first Indian solar mission scheduled to be placed in a halo orbit around the first Lagrangian point (L1) of Sun-Earth system in the year 2018. The approved scientific payloads onboard Aditya-L1 spacecraft includes a Fluxgate Digital Magnetometer (FGM) to measure the local magnetic field which is necessary to supplement the outcome of other scientific experiments onboard. The in-situ vector magnetic field data at L1 is essential for better understanding of the data provided by the particle and plasma analysis experiments, on board Aditya-L1 mission. Also, the dynamics of Coronal Mass Ejections (CMEs) can be better understood with the help of in-situ magnetic field data at the L1 point region. This data will also serve as crucial input for the short lead-time space weather forecasting models.

The proposed FGM is a dual range 3-axis magnetic sensor sits on a six metre long boom mounted on the EP-01 [Earth viewing Panel] deck and configured to deploy along the negative roll direction of the spacecraft. Two sets of sensors (three-axial each) are proposed to be mounted, one at the tip of boom (6 m from the spacecraft) and other, midway (3 m from the spacecraft). The main science objective of this experiment is to measure the magnitude and nature of the interplanetary magnetic field (IMF) locally and to study the disturbed magnetic conditions and extreme solar events by detecting the CME from Sun as a transient event. The proposed secondary science objectives are to study the impact of interplanetary structures and shock solar wind interaction on geo-space environment and to detect low frequency plasma waves emanating from the solar corona at L1 point. This will provide a better understanding on how the Sun affects interplanetary space.

In this paper, we shall give the methodology to achieve the proposed scientific objectives of the magnetic field experiment and brief technical details of the proposed FGM onboard Aditya-L1 spacecraft.