Currently, many studies and researches are being conducted in areas such as plasma physics and plasma technologies. Plasma, a modern technology, is used in various fields and its application areas are increasing daily. We talked about plasma, which has a wide range of areas of use such as energy, metallurgy, medicine, textile, automotive and space, with Prof. Necdet Aslan, a lecturer at Yeditepe University.
Necdet, can you tell us about yourself?
I graduated from Hacettepe University Department of Physical Engineering, ranking first in class. I started to do my master’s degree at ODTU Nuclear Engineering Department. After passing the Ministry of Education’s overseas scholarship exam in 1985 at 1st rank, I started my master’s and doctorate studies at the University of Michigan in the US, without completing my master’s degree in Türkiye. It was a great chance for me to get education from a Turkish scientist like Prof. Ziya Akcasu at University of Michigan. My master’s thesis was also on experimental studies on plasma. After returning to Türkiye, together with a few friends who have developed themselves in the field of physics, we started working at the newly established Marmara University Physics Department. I worked as a lecturer at this university for 6 years. In addition to my teaching duties, I have worked as a consultant for leading electronics companies, and also worked as an R&D coordinator. After receiving an offer from Yeditepe University in 1998, I decided to work here.
Could you tell us about your studies at the university and the dialog you have with your students?
I have always loved being together with students and spending time with them. In addition to lecturing, I share with them all kinds of information that can benefit them in their business lives. I think that the university environment should be free, which I found at Yeditepe University. When I’m not at the university, I leave my students the key to my room or laboratory, and make sure that they can easily use the resources there. We have established student clubs at the university. In 2005, together with a few of my students, we built a single-seater solar car, which is 4.5 meters long, 2 meters wide and powered by an electric motor. We brought many parts of the vehicle from abroad. We also converted the solar cells we purchased into panels with my students. The vehicle we designed won the third place in the first solar car competition in Türkiye organized by TUBITAK. Since 2005, I have been attending TV programs, conferences and panels to convey the importance of solar energy and electric motor to people. We have received awards for international projects with many academic studies we have complete at the university. We have received project support budgets from the US National Science Foundation, one of the few science foundations in the world, as well as NATO. Together with many European countries, we are carrying out important works under bilateral cooperation projects.
You are working as a lecturer at Yeditepe University. You also have a company. Can you tell us about the activities of your company?
In 2010, I founded ELES Elektromekanik to manufacture physics, electronics, mechanics and optical experiment sets with advanced technology. The aim of our company is to offer innovative experiment sets that we produce using our domestic facilities according to international standards to people and institutions who need them. These experimental sets come from abroad and are quite expensive. We are creating a more affordable solution in terms of cost. We aim to increase their use in primary education, secondary education, technical high schools and universities. A simple set of experiments brought from abroad costs a minimum of 2-3 thousand euros. A set of experiments available in universities and high schools can offer many students the opportunity to carry out experiments, and there are dozens of students in each laboratory at the same time. Every student should observe the scientific experiment method, which is one of the most basic elements of physics. To date, we have sold experiment kits to 40 universities. Our experiment sets are used in important high schools such as London High School. When an experimental set order comes from 3 different companies that we work with both directly from schools and as a solution partner, we focus on production for 1-2 weeks with our expert team and some students. Our company has reached the capacity to produce about 100 sets of experiments a month. Our mission is to prepare our young people for a bright future. Because I believe in this, I also attach great importance to my duties in the field of education. For this reason, my company always comes second for me, while it also serves an important purpose as it supports education. I am quite satisfied with this.
What are your areas of expertise?
Technically speaking, physics occupies the biggest place, as it includes almost all branches of science. I started to feel how sacred profession physics is, even from my high school years. Plasma technology is one of my areas of expertise. During the associate professor exam, one of the jury teachers have asked, “How do you tell your students about plasma when you enter the classroom?” This was actually the first question. I told the students in the classroom to look up the fluorescent lights on the ceiling, mentioning that they were plasma, and told that they were looking at a plasma right now. On top of this answer, I also drew both the shape of the plasma in the tube and the SMPS circuit that will operate it. They were so impressed by my speeches that they didn’t need to ask any more questions, and at that moment they dressed me in a robe and I won the associate professorship. In addition to both numerical and experimental plasma fields, my other specialty is designing, manufacturing and marketing both DC and AC (50 Hz or 1-30 kHz) high voltage power supplies. I produce power supplies such as DC and AC of 15k volts, 20k volts and 40k volts whose frequency, amplitude and electrode structure can be adjusted, and sell them through my company. As a Turkish company, we are the only one producing these. Forming the plasma (diagnostics), as well as the conditions required for this and identifying their properties are also among my areas of expertise.
“In 2005, together with a few of my students, we built a single-seater solar car,
which is 4.5 meters long, 2 meters wide and powered by an electric motor.”
Can you tell us about plasma technology?
Plasma is considered the “fourth state of matter”, and the positively and negatively charged gas express the entire collective motion of particles. While the gaseous states of all substances are insulators, the plasma state conducts electricity very well and is even affected by the magnetic field. This is the major feature of plasma. Plasma is formed not in the atmosphere we breathe, but in the ionosphere, which is located at much higher levels, due to very energetic photons and cosmic rays from space (especially from the Sun). Lightnings that dissipate and destroy this energy are among the most beautiful examples of natural plasma. The Sun, which has a nucleus at a very high temperature and whose atoms have been separated from their electrons, is also a plasma. Theoretically, the lowest temperature is 0 Kelvin, i.e. -273.15 degrees Celsius. While there is a lower limit to the temperature, there is no upper limit. Due to the high temperature of hundreds of thousands or even millions of degrees in the Sun’s nucleus, atoms completely lose their electrons and conduct nuclear fusion reactions as fully ionized, which sustains the plasma. According to Albert Einstein’s Nobel Prize-winning work Photo Electricity, Sun is also the source of photons that move electrons on metal surfaces, thereby a plasma that gives us life. We need energy to be able to convert a gas into a plasma.
This is what the Universe does: When cosmic rays or other radiation from the Sun first enter the ionosphere, it begins to give energy. The electrons in the atoms of the gas receiving the energy move, and positive and negative ions appear. We call a neutral atom “an ion” when it loses electrons. These increasing amounts of charge also turn into lightnings, which are actually another state of plasma. The electrons of each element may also differ. Hydrogen has 1, helium has 2, and uranium has 238 electrons. During the first formation of the universe, there were elements much heavier than uranium, with about a thousand electrons. Atoms that are engaged in radioactive decay are constantly transforming into their most basic state. This decay takes millions of years. In order to create plasma in a vacuum environment in the laboratory, we usually use argon gas, which does not react with the material. By energizing this gas placed in a vacuum, a conductive plasma environment is created inside, and thin film layers can be formed on surfaces from desired materials using the atomic evaporation or removal technique in this environment. This is the cornerstone of semiconductor and sensor manufacturing. This is a very expensive technology, as both mechanical and diffusion or turbo pumps are needed in these systems. Of course, if we can produce these systems from start to finish locally, the situation may change. It is also possible to produce plasma in an atmospheric pressure environment. We pass gases such as nitrogen argon through a certain tube using very little oxygen. We drill a hole through the nozzle at the end of the tube as an electrode. The internal structure of the hole is in the form of a grooved spiral. Just before the gas reaches the end of the tube, a high voltage of 1-10k volts is applied in an area of 1-2 cm, and thus the gas or gas mixture comes out of the end as transformed into plasma. If these are made with multi-current power sources, they act as a welding machine, but if the current is low, they come out as a beam very slightly above room temperature. This plasma has an incredible effect on the material surface. This cold plasma changes the surface tension, gives it a hyrophobic or hydrophilic property, allows the primer-free application of paints to metals, increases adhesion to the surface, and even provides sterilization.
In which sectors are plasma technologies mainly used?
It is mainly used in general lighting products. Among the plasma objects we use in our daily lives are fluorescent lamps, plasma televisions, air conditioners, and sterilization devices. Today, they are used in various fields such as medicine, textile, aircraft industry, automobile, paper, diamond, electronic chip making, defense industry, crystal magnification, radar research and launching rockets in space technology. As a result of the increase in people’s expectations about food in recent years, the quality of food sterilization without affecting the food itself began to become more important. In one of our projects, we extended the shelf life of milk by sterilizing milk using plasma technology, and received awards from many foreign organizations with this project. Coatings can also be applied on glass, nylon and textile surfaces with plasma technology. In order to do this, we use the method we call “dielectric barrier discharge”. Some brands paint the car bumpers after passing it through the plasma, so that the paint never comes off.
What are your suggestions for the development of advanced technology and plasma industry in Türkiye?
First of all, we should eliminate our dependence on foreign countries in engine production, and our companies should produce their own engines. The production of neodium magnets in the internal components of motors in our country is of great importance in a strategic sense. Neodium is one of the magnets with a strong magnetic field. Very few companies produce vacuum pump production. We need to move faster in the production of mechanical, turbo-molecular and diffusion vacuum pumps. We are designing such systems with a friend we are working with. One of the most important uses of plasma is nuclear fusion technology. Due to the very high temperature of the Sun, atoms fuse with each other to form heavier nuclei. The result is fusion reactions such as neutrons and gamma rays. High energy is released by these reactions that occur at the core of the Sun and in all its layers near the surface. If 2 light nuclei form a heavy nucleus, it’s called “fusion”, and if a heavy nucleus splits into light parts, it’s called “fission”. Fission occurs when uranium is broken down by the neutron effect. The fault line in the Black Sea Region contains thorium reserves. Using this thorium, nuclear reactors can be built much more reliably with a much lower risk of accidents.
This resource is the second largest in the world, and if we can use it effectively in the future, we can become one of the most developed countries. But for this, we need to work together as a nation. The fuel of fusion reactors, which are not fully operational yet but will start working very soon, can be supplied with deuterium. We can get deuterium dioxide, i.e. heavy water, from the depths of the Black Sea. We can also produce deuterium from this. As you can see, we have fuel for a nuclear fusion reactor too. Although it is an expensive technology, we can produce our own energy by eliminating our energy dependence thanks to nuclear fusion technology as well as nuclear fission. We call the tool that is often used in fusion studies a “tokamak”. Tokamak, just like a conventional power plant, a fusion power plant uses these turbines and generators to generate steam and then heat to generate electricity. As Türkiye, we are also a member of the International Tokamak (ITER).
“Very few companies produce vacuum pump production. We need to move faster
in the production of mechanical, turbo-molecular and diffusion vacuum pumps.”
Could you tell us about the activities of the National Metrology Institute?
I am taking part in the activities of establishing a laboratory in the field of plasma metrology at the National Institute of Metrology by TUBITAK. We aim to secure all the measurements made in the plasma field in Türkiye, ensure the integration of these measurements into the international system, and develop existing and new measurement technologies. Currently, we have a team of 4 people working on plasma technology. We strive to carry out works that will go off with a bang in the near future.
One of the new technologies developing in the world is autonomous vehicles. We know that you are also working on autonomous vehicles. Can you tell us a little about it?
I believe that driverless (or autonomous) cars will also lead to an unprecedented economic, social and environmental change in the near future. Technologies such as sensitive sensor data, extensive data analysis, machine learning and artificial intelligence are used in autonomous vehicles. With the sensors in the autonomous vehicle, which are actually ultrasonic distance sensors and Lidar radars, it detects people, structures, traffic signs and road lanes in the surrounding area and continues on its way accordingly. We started with the solar car we produced in 2005, then focused on electric vehicles, and now we have converted one of our vehicles into an autonomous vehicle. We will participate in the autonomous vehicle race to be organized at Teknofest together with Baris Volkan Aslan, an electronic engineering student who is the autonomous vehicle team captain, and our other students.
