There are several research projects currently being conducted at the BUST-Lab. Please click here for the journal publications, conference proceedings and dissertations.

The goal of this effort is to build a vacuum chamber that will be capable of providing the desired vacuum environment for plasma thruster testing. The plan is to purchase all the necessary components and then putting them together to have a functioning test facility. The chamber has already been bought and placed inside the laboratory space. The pumps, compressors, chillers and other relevant components are either bought, ordered or about to be ordered. If built, this chamber will be the first vacuum chamber in Turkey that will be capable of supporting space propulsion research. This research is being subborted by Bogazici University Office of Scientific Research Funds with project number BAP-6184.

Assoc. Prof. Huseyin Yilmaz is a consultant and a major contributor to any work done related to the construction of the chamber. He is also an official adviser to the TUBITAK- 112M862 and TUBITAK-113M244 projects. His advise/contribution has been crucial. Without his support such a facility and other experimental research work would not have progressed as much as they did. His expertise in the fields of vacuum systems, in materials, in manufacturing has been invaluable.

This research involves the AETHER code development. The aim is to model the RF ion thruster discharge chamber plasma. The code is written in C++.

Emre Turkoz is working on this topic. This project is being supported by TUBITAK, under the project number TUBITAK-113M244.

This research project involves the design, manufacturing and testing of a small hollow cathode. The device will have a keeper electrode of ~40 mm in length and ~20 mm in diameter. The cathode will utilize 10, 15 or 20mm long LaB6 insert material. This project is being supported by TUBITAK, under the project number TUBITAK-112M862.

Currently Ali Enes Ozturk and Oguz Korkmaz are working on this research endeavor.

This research project involves the building a 40mm diameter cusped field Hall thruster. The work also entails modelling the magnetic field using COMSOL multiphysics.

Currently, Yavuz Emre Kamis is working on the modeling part of this project.

This research project involves theoretical study of the RF cathode concept. Use of COM- SOL multi-physics program is being considered for various modeling efforts. Eventually, a prototype will be built and experimental work will be conducted.

Sina Jahanbakhsh is working on this topic.

This research project involves developing numerical models to simulate the plasma in the insert and the orifice regions of a hollow cathode. The initial work will be on the 0-D global mass and energy balance. Later on a 2-D model will be developed. The codes are being written in MATLAB. This project is being supported by TUBITAK, under the project number TUBITAK-112M862.

Oguz Korkmaz is working on this research project.

This research project involves the design and manufacuring of a 40mm diameter SPT type Hall thruster. The work also involves the study of Hall thruster scaling. This scaling effort will involve some theoretical and some modeling work.

This research project involves the building a prototype RF ion thruster that is capable of producing 2-4 mN of thrust. The proposed thruster will be 80mm in diameter. This project is being supported by TUBITAK, under the project number TUBITAK-113M244.

Currently Firat Sık is looking into the part gathering and machining part of this work.

This research involves the study of microwave heating of propellant gas that will later on be expanded to produce thrust. The work involves the study of wave plasma interactions. The aim is to build a prototype thruster and conduct various parametric tests. The research also involves conducting certain modeling using COMSOL multi-physics program. This research is being subborted by Bogazici University Office of Scientific Research Funds under the project number BAP-8960.

Mehmet Serhan Yıldız is conducting this research work.

This research involves building various plasma diagnostic probes and conducting plasma measurements. Manufacturing a Langmuir probe, a Faraday probe and a retarding potential analyzer (RPA) are among the plans for this research effort. This project is being supported by TUBITAK, under the project number TUBITAK-113M244.

Mert Satır is taking the lead in this research project.

This research will involve designing and then manufacturing a cylindrical thermal test section to be placed inside the large vacuum chamber.

The plan is to have Nazli Turan to take the responsibility in this research project.

This research involves writing a hybrid-PIC plasma model for the intragrid region of the ion thruster. The code is being written in C++.

Currently, Emre Turkoz is working on this project. He is receiving help from Firat Sık for the code development effort.

This research project involves the investigation of the phenomenon of anode spot both theoretically and experimentaly.

This research project involves the numerical investigation of the plasma thruster - spacecraft integration issues. This research involves the study of the plasma thruster plume expansion and its interaction with spacecraft surfaces and operations.

There are currently three active funding for the projects: one BAP project and two TUBITAK-1001 projects. BAP-Infrastructure project wsa succesfuly closed in March 2014.

In-space propulsion of spacecrafts and satellites are provided by specially designed thrusters that operature efficiently in vacuum environment of interplanetary-space or earths orbit. In order to develop and test thrusters to be deployed on spacecrafts or satellites, vacuum facilities that provide the vacuum environment that is similar to the environment in low earth orbit are used. In this project, the acquisition and construction of a vacuum facility that is going to be used in the development and testing of in-space propulsion systems are made. The constructed vacuum facility should provide the vacuum environment that is similar to the environment in low earth orbit even when a thruster is in operation inside the chamber (when releasing gas into the chamber). The vacuum facility will primarily be used to develop electric spacecraft thrusters that run on Xenon or Argon propellants. Thus, as a baseline requirement the vacuum facility (1.5m in diameter, 2m in length) should employ pumping systems that is well suited to pump Xenon and Argon gases and maintain a vacuum level of 2x10−5 Torr when 1 mg/min of gas is being released by the thruster.

This BAP project had a total budget of 222k TL. This project has officially began on April 9, 2012 as a 1 year project. It was granted a 1 year extension. It was succesuly closed in March, 2014. There was about 26k TL unspent money in this project’s budget, but it was not possible to spend it due to autorization issues.

This project proposal was submitted on September 7, 2012 and the announcement for the awardees were made on January 11, 2013. This project officially began on March 15, 2013. It has a duration of 3 years with a total budget of 390k TL including the payment for the department and the PTI. This project promises the manufacturing and testing of a hollow cathode and a numerical modeling effort for the cathode insert region plasma.

Ion engines and Hall effect thrusters need a cathode for two reasons. The first reason is to supply the electrons needed to ionize the neutral propellant gas. Ionization is needed, because the Hall effect thrusters and ion engines work on the principle of electromagnetic forces accelerating the charged particles of the propellant. In both the standard (Kauffman type) ion engines and the Hall effect thrusters the ionization of the propellant gas, thus the plasma generation, occurs with the process called electron-impact Ionization. For this ionization process, the required electrons are supplied by a hollow cathode. The second reason is to provide the electrons needed to neutralize the ion beam leaving the thruster, thus the satellite or spacecraft. This is needed to prevent the spacecraft from charging (thus preventing the propulsion systems continued operation). In terms of the performance and the operational life of both the Hall effect thrusters and the ion engines, the cathode material, physical configuration and the structure are of great importance.

This project will have two major parts, an experimental and a theoretical (modeling) part. On the experimental side, a lanthanum hexaboride (LaB6) hollow cathode to be used for the operation of an ion engine or a Hall effect thruster will be designed and manufactured. Lanthanum hexaboride has been chosen as the cathode insert material, because of its lesser sensitivity to impurities in the propellant gas and lesser sensitivity to humidity, and its better suitability to laboratory testing where exposure to atmosphere is common. In the development of the hallow cathode, the studies and designs at NASA’s Jet Propulsion Laboratory (JPL) will be used as a reference starting point. The target current values will be in the 0.5-3.0 Ampere range. In order to achieve the targeted cathode current levels, the propellant flow to the cathode will be adjusted. It is estimated that a 100W heater unit will be required to allow the starting of the cathode within 120 minutes. After the cathode starts its operation no other heater power would be required.

On the theoretical side a two dimensional axisymmetric numerical model of the discharge region of a hollow cathode will be developed. The driving physics inside orificed hollow cathodes is not well understood. Such a study will complement and aid the development effort of the cathode.

As part of this project it is possible to employ 3 graduate and 1 undergraduate students at a given time. Graduate students (Oguz Korkmaz, Sina Jahanbakhsh and Ali Enes Ozturk) and undergraduate student (Firat Sik) are being paid through this project’s budget.

This project proposal was submitted on March 8, 2013 and the announcement for the awardees were made on July 12, 2013. This project officially began on October 1, 2013. It has a duration of 3 years with a total budget of 440k TL including the payment for the department and PTI.

This project will consist of experimental and theoretical (modeling) parts. In the experimental part of the project, a prototype radio-frequency ion engine will be designed, manufactured and preliminary performance tests will be carried out. The prototype ion engine that will be produced as part of this project is expected to have a cylindrical discharge chamber of 72mm in diameter and 70mm in length. Due to the fact that the produced ion engine will only be a laboratory prototype, initially the grids with 91 and 127 holes packed in a hexagonal shape are going to be manufactured and the necessary tests will be performed. During the design phase different materials and production methods will also be investigated. The design and the manufacturing of the prototype ion engine will benefit from the studies and designs of NASA’s Jet Propulsion Laboratory (JPL) and the research conducted under the partnership of University of Giessen and EADS Astrium in Germany. The targeted thrust value of the prototype ion engine is in the range of 2-4 mN. In order to achive this thrust, the propellant flow rate, the grid spacing, and the discharge potential values will be adjusted. Other desired parametric studies will be conducted.

In the theoretical part of the project, the ionization chamber of the radio-frequency ion engine will be modeled. In radio-frequency ion engines, the ionization of the neutral propellant gas is achieved by an antenna wrapped around the ionization chamber. The working principle behind the ionization of the neutral propellant gas using the energy transmitted to the plasma by radio frequency waves will be studied. Modeling of the ionization chamber plasma of an RF ion engine is related to an important research topic called the inductively coupled plasma (ICP). With the numerical model that will be developed as part of this research, an important step towards the understanding of the working principle of an RF ion engine will be made. The developed model will also be used in the design phase as well as the analysis of the test results of the prototype thruster.

As part of this project it will be possible to employ 3 graduate and 1 undergraduate students. Graduate students (Mert Satir, Nazli Turan and Yavuz Emre Kamis) and undergraduate stunent (Yigit Can Sezgin) are being paid through this project’s budget. However, the work conducted by Emre Turkoz had been directly related to the promised work in this project. Emre Turkoz has been an unpaid graduate student in tbis project.

In this project resonant cavity which is working in TM₀₁₁ mode for microwave electrothermal thruster which uses 2.45 GHz frequency and 1 kW power will be designed, produced and numeric analysis will be done. Project will have both experimental and numerical modeling parts. In the experimental part of the proposed project a prototype resonant cavity will be designed, suitable production methods will be searched and chosen, a prototype will be produced. In the theoretical part, modeling of resonant cavity will be done by using a commercial software. Effect of cavity geometry on the electric field distribution in the cavity will be is examined. Ensuing work will be done on enhancing the system efficiency and integration of the components of the microwave electrothermal thruster system.

This BAP project has a total budget of 35k TL. This project has officially began on September 30, 2014 as a 1 year project.