• Feeding System HET
• Hall Effect Thrusters
• Iodine based Hall effect Thrusters
• Iodine fed HET

Electric propulsion was envisioned almost 100 years ago, and throughout most of the 20th century was considered the technology of the future for spacecraft propulsion. Electric Propulsion basically involves propulsion technology where electricity is used to increase the exhaust velocity of a propellant. There are many figures of merit for Electric propulsion, but its increased popularity is mostly due to: increased commercial availability and capability to perform same tasks as any conventional chemical propulsion system but at a reduced spacecraft mass.

Hall effect thrusters (HETs) are a specific class of Electric thrusters i.e. Electrostatic type, that operate with propellant in the form of plasma. Today's flight qualified HETs operate on noble gas xenon (Xe) which is inert, heavy with a large ionization cross section but relatively rare and expensive. Hence, the research to replace xenon has been going on for more than a decade. So far, the most suitable propellant to replace xenon in HETs has been identified as iodine. Iodine as opposed to xenon, has excellent storage capability and is abundantly available at low cost. Already various architectures have been proposed for HETs utilising Iodine as propellant. Being a reactive element, the feeding system for iodine should be modified from the one currently being utilised. For the feeding system of iodine fed HETs, architecture has been proposed and developed by the University of Pisa (UniPi).

This thesis work is carried out to collaborate further to the development of iodine based HETs. For the proposed architecture by UniPi, feeding system is proposed using thermal throttle (TT). The thesis work essentially involves development of thermal throttle for the feeding system. After elaborating the architecture for new HET, simulations were carried out for thermo-fluid dynamic assessment of the system. Later, experiments were carried out independently to validate the proposed model. First experiment consists of the assessment of mass flow rate dependence on TT temperature using flow of air through the system. Then, a mass flow meter based on laser is proposed and finally experiments are carried out to observe the function of the proposed mass flow meter.

The work has been carried out in the framework of the Technology Research Project "I2 HET: Use of Iodine as Propellant for Hall Effect Thrusters" sponsored by the European Space Agency.