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Research Initiatives |
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Research Grants
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Current Research Projects |
#1 Deposition and processing of thin films using repetitive plasma focus device Thin films are potentially useful for different industrial fields ranging from tribology to microelectronics and optics. We propose to deposit and process thin films using repetitive as well as single shot plasma focus facilities available at NIE. These focus facilities have already produced 5 Ph.D.s and 1 Masters at NIE. The single shot plasma focus facility has already been used for the deposition of TiN and TiC thin films and processing of antimony telluride thin films. Two honours students Academic Exercises have been performed using these devices in the past and one more is under progress. International Centre for Dense Magnetized Plasma, Warsaw, Poland, a institute dedicated to high energy plasma focus device has initiated studies on developing focus device for deposition and processing of thin films. However, so far, only single shot focus devices have been used film deposition and processing using multiple focus shots. We hereby wish to extend this technology of deposition and processing of thin films using high performance repetitive plasma focus device (NX2) available at NIE. We plan to deposit thin films of diamond like carbon, silicon and others. Thin films for processing purposes to study the change in films characteristics on exposure to high ion doses will be procured from plasma processing lab at NIE and other available resources within NTU.
Recent technological and industrial applications, such as MEMS, special microlithography, material and surface processing, as well as medical and microbiological processes and techniques require intense pulsed X-ray, ion and electron sources. The plasma focus source is a very promising candidate for such applications. The NX2 plasma focus device from the NIE laboratories is one of the most advanced pulsed, point X-ray source. The NX2 machine was originally designed as a state-of-the-art X-ray source for advanced research. However the full potential of this machine is yet untapped. The NX2 device can be used as both X-ray source and electron beam generator and can be optimised in a reversible manner for any of these applications. Therefore this project is devoted to the modification of this plasma focus device in order to be able to function as a powerful repetitive electron beam source. In the mean time, the device can be used as an ion and neutron source. Some intended applications for the NX2 device working as an electron beam generator are in material processing, ablation, thin film deposition and surface modifications, as well as for triggering high power devices. Another major outcome of this project is the use of the NX2 device for training and teaching. Apart of the work leading to 7 Ph.D. and 1 M.Sc. titles within 6 years, the plasma focus devices and particularly the NX2 machine were used for honours projects, and for junior college experiments, with extraordinary results. Due to the wide area of expertise required by the design and the operation of such machines, all the post graduated students trained them were able to find good jobs after finishing their studies, in areas related to research and development, or teaching in Universities. Five out of the seven PhDs are working now in research-related companies or laboratories, two of them in the biosensor field. Various new diagnostic techniques have been already developed and implemented as results of extensive research work in these fields. During the project we will built or study the feasibility of some other new diagnostics. The fundamental data will contribute to the knowledge base of plasma physics and technology, particle beam science, pulse power and fusion technology.
#3 Pulsed laser deposition of nano-sized CrCo/FeCo magnetic thin films: Pulsed laser ablation is one of key techniques for the thin film deposition and nano-powder synthesis and is being used extensively by researchers all over the world. We at NIE, have a 10 Hz, 1064nm wavelength, Nd:YAG laser, with pulse energy of 0.17-0.45 J and pulse duration of 5-14 ns which has been extensively used in the past essentially for investigation of high density laser-mater interaction studies (two Doctoral degrees have been awarded on these studies). Recently, we have started using this laser for thin film deposition and have successfully deposited diamond like carbon and high-k thin films. In the proposed project we wish to use this Nd:YAG laser for deposition of nano-structured magnetic thin films of CrCo/FeCo. The role of nano-structure on the extrinsic magnetic properties of the materials would be studied and an analysis of how the nano-structures play an important role in the improvement of magnetic properties will be carried out. Our focus area would be to achieve smallest nano-size thin film for various magnetic materials (CrCo/FeCo) used for data storage applications in microelectronics industry. To control the micro/nano structure of the deposited/synthesized material, the ablated plasma plume will be intensively characterized using space and time resolved emission spectroscopy.
#4 Dense Plasma Focus Production of Positron-Emission-Tomography Isotopes Positron Emission Tomography (PET) is one of the fastest growing medical imaging techniques in the world today. It is now established as an essential imaging technique in the fields of oncology, cardiology and neurology. However PET is still an expensive medical procedure. The very high cost of isotope production, using a cyclotron located near to the PET scanner is a major obstacle to cheaper and more widespread application of PET imaging in medicine. The objective of this project is to investigate the production of PET isotopes (11C, 13N, 15O, 18F) using a repetitive plasma focus. A cyclotron for PET typically costs US$1.2 million to US$1.7 million. By comparison with cyclotrons, Plasma Focus devices are very compact, simple and inexpensive machines. Hence, PET isotope production based on a repetitive plasma focus device will offer very significant cost-advantages.Our group will involve Secondary, JC and undergraduate students in this research work – as we have frequently done before. This experience will enable them to understand how research work is conducted, and also about the nature of technological innovation and enterprise in the rapidly developing field of bio-medical imaging.
#5 Xenon Flash Tube Plasma Characterization This project is fully funded, to the tune of $89,930, by the PerkinElmer Singapore Pte Ltd which is the Asian Headquarter for PerkinElmer Optoelectronic, a global technology leader providing market-driven, integrated solutions for biomedical and industrial applications. The PerkinElmer, Inc (PKI) has been in the development and production of Xenon flash lamps for more than 30 years. The major objective of the project is to enhance Xenon flashtubes performance through the understanding of the relationship between flash lamp & circuit system input parameters and plasma characteristic. The PKI has agreed to provide funds for the employment of a research fellow and for the usage of resources, including expertise in plasma characterization,at Plasma Radiation Source Lab of NIE for the successful completion of the project. This intensive one year project has formally started on March 1, 2005 and Dr Zviad Tsakadze has been employed as the research fellow. This fully funded industrially-supported project recognizes the expertise, strength, potential and standing of plasma research group of NIE.
#6 Dense Magnetized Plasma Applications Funding from the IAEA is in the form of a Coordinated Research Contract (contract no: 12412/R0) entitled “Dense Magnetized Plasma Applications”. This research is based on the Dense Plasma Focus (DPF) devices built and studied within our group in NSSE, NIE, NTU. In particular the NX2 plasma focus device is employed as an intense short-duration high repetition-rate source of intense ion beams and neutrons. A/P Stuart V Springham is the Principle Investigator. There are four cooperating investigators (from NSSE) involved in this research project, namely: Ast/P Paul Lee, Ast/P Rajdeep Singh Rawat, A/P Augustine Tan Tuck Lee and Dr. Alin Patran. The two principal objectives of the work are: Objective 1) Investigation of fusion mechanisms (e.g. beam-target vs. thermonuclear fusion) in the Deuterium DPF ― aimed at enhancing neutron yield for applications such as Prompt Gamma Activation Analysis (PGAA) and neutron radiography. Objective 2) Investigation of DPF energetic ion beams for plasma fusion related applications.
#7 Neutron Emission Studies on Plasma Focus with Twisted Cathode Recently, with modified and optimized NX2 device with tapered central electrode, one of the highest neutron yield of 7*108 neutrons/shot has been reported by PRSL research group. This has led to the increased interest in further developing this device for enhanced neutron emission. Motivated with the excellent neutron yield from NX2 device, Dr Mahadevan Krishnan, President, AASC wishes to test one of his ideas of further increasing the neutron yield with the application of twisted cathode geometry along with the other neutron emission studies undertaken by NTU’s PRSL research group. The focus of this project is to employ twisted cathode geometry instead of the present linear squirrel cage geometry of NX2 cathode.
#8 Development of EUV source for Nano-lithography Modern technology is strongly dependent on microelectronics which is in turn dependent on microlithography technology. The electronics industry accounts for half of Singapore’s US$120 billion manufacturing output. Worldwide there is a current interest in life sciences, nano-sciences and photonics. These new areas of science can develop in the near future if there is the ability to produce nano-sized (< 100nm) structures. Our group has been one of the pioneers of soft x-ray lithography source research in the region. We have also demonstrated the use of alternative radiation (including harder x-rays and electrons) for micro-lithography. Many of the current methods for producing Extreme Ultra Violet-EUV (crucial for the next generation “nanolithography”) involve the use of plasmas and NIE has the only plasma physics group in Singapore. Much work has been done on EUV sources using Laser Produced Plasmas (LPP), Discharge Produced Plasmas (DPP) and synchrotrons (The only synchrotron facility in Singapore is SSLS at NUS). However the advantage of one method over the others has yet to be established. Our project aims to understand the physics of the various methods and clearly determine the scalability and limitations of each type of sources. In addition we will investigate promising new DPP candidates as EUV source e.g. the miniature dense plasma focus (mDPF) device. The conventional DPF achieves temperatures of ~10million Kelvin, which is suitable for soft x-ray production but not for efficient EUV production. The mDPF is expected to be different from the conventional DPF if we can operate at temperatures 2 orders of magnitude lower, to achieve temperatures suitable for EUV radiations. Our approach is unique in that we will simultaneously investigate a large number of alternative sources to test the competitiveness and efficiency of each one of them for nano-lithgraphy.
#9 Development of EUV source for Nano-lithography - SEP Grant of #8
#10 Time resolved spectroscopy and imaging of laser produced plasmas Pulsed laser ablation is one of key techniques for the thin film deposition and nano-powder synthesis and is being used extensively by researchers all over the world. Recently, we have started using this laser for thin film deposition and have successfully deposited diamond like carbon and high-k thin films. In the proposed project we wish to use this Nd:YAG laser for deposition of nano-structured magnetic thin films of CrCo/FeCo. Our focus area would be to achieve smallest nano-size thin film for various magnetic materials (CrCo/FeCo) used for data storage applications in microelectronics industry. To control the micro/nano structure of the deposited/synthesized material, the ablated plasma plume will be intensively characterized using space and time resolved emission spectroscopy and time resolved imaging.
#11 DPF production of PET Isotopes - SEP Grant of #4
#12 Neutrom emission studies from miniature and medium size plasma focus device A plasma focus (PF) is a kind of pinch discharge that has emerged as an excellent device for fundamental and applied research related to fusion, neutron production, hard and soft x-rays and intense charged particle beams. PF devices can produce bursts of neutrons with energies of 2.5-3, 10–11 or 14MeV depending on the gas fuelling the machine. The overall emission varies with the fourth power of the current (or I3.3 as accepted by many). This scaling law is valid for capacitor bank energies ranging from about 1 kJ to about 500 kJ. With the modified PF head our group at NTU has reported the highest neutron emission of 7 × 108 neutrons/shot from a 2.8 kJ NX2 PF device which is more than a five fold increase when compared to other devices of that energy. The proposed project, however, aims to develop a miniature, low energy (<200J) PF device that can be operated at higher repetition rate (~10 Hz) and thus will have the potential to be developed as a hand held neutron gun with appreciable flux. We wish to develop a miniaturized <200J PF, with substantially low inductance for maximization of peak discharge current, which once optimized, will be able to generate neutrons of the order of high 105 or even 106 per shot. This PF device if operated at >100 Hz repetition rate will be equivalent to a lower rep-rate, 5-10 kJ PF machine in terms of neutron emission rate per second, but will have the advantage of being hand held device because of its much smaller size. At the same time the NX2 will be used as the platform to test innovative DPF heads and cathode geometries for further improvement in neutron emission which later will be scaled down for their testing on the miniature PF device.
#13 TEA Nitrogen Laser shadowgraphic system for current sheath dynamics studies A TEA nitrogen laser system along with high voltage power supply, trigger circuit and delay unit will be constructed. The laser then will be used to conduct shadowgraphic studies of current sheath dynamics for plasma focus with different electrode shapes. In the recent past the electrodes of different shape have been found to effect the X-ray emission from plasma focus device. If the time permits then during the course of this three month project the effect of anode shape on the current sheath dynamics will be investigated.
#14 Development of MOKE setup for measurement of magnetic properties of thin films Recently, we have successfully synthesized Fe and FeCo nanoparticles and nanocluster based thin films using pulsed laser deposition as well as plasma focus device in our lab. So far we have been mainly concentrating on the synthesis, morphological and structural properties of the synthesized material rather than their magnetic properties. We have been using VSM for magnetic properties measurements whose sensitivity is rather limited and hence it was difficult to measure the magnetic properties whenever the thickness of thin film was less than 100 nm or amount of magnetic nanoparticles were not enough. One of our major research thrust area for next one year would be to work on thin magnetic films and magnetic nanocomposites material for which VSM would be inadequate. Other ways to measure magnetic properties would be to use either SQUID or MOKE setup. We plan to design, test and setup a low cost magneto-optical Kerr effect (MOKE) magnetometer to measure magnetic properties for which many of the basic equipment such as Laser, Lockin-amplifier, optical chopper etc are already there in our Laser Technology Lab. MOKE is a powerful setup to characterize magnetic properties of ultra-thin films, since the region contributes to the Kerr rotation is rather thin, typically in the order of 10 – 20 nm. A small financial support for some additional equipment and consumable will enable us setup the fully integrated MOKE facility for magnetic property measurement of ultra thin films. MOKE system can then be used to investigate surface magnetic anisotropy, determine Curie and Neel temperatures, and measure coercivity, and other features of surface magnetism.
#15 Novel Fusion Material Studies and Pulsed Fast Neutron Analysis using High Performance Plasma Focus Device Recently, there has been considerable effort world-wide in fusion research and technology due to ITER (7 major partners), NIF (US), and ZR (US) programs. Main aim of the proposed program is to investigate one of the key fusion reactor problems i.e. testing the suitability of various candidate materials of plasma facing component of the future fusion reactor. The proposed program aims to develop and operate a state-of-the-art high performance high-energy (20kJ) dense plasma focus facility. The planned facility will facilitate the exposure of candidate materials (such as ferritic-martensitic steel, CuCrZr, W and V alloy, SiC etc to be used for existing and future fusion devices under exposure to plasma and fusion product fluxes as well as under transient heat loads) to the high flux plasma and radiation stream in dense plasma focus device. Under the scope of this project, the primary aim will be to investigate the amount of irradiation induced damage caused to the potential candidate material by the dense magnetized plasma, radiation and fusion product fluxes to judge their suitability. The program also aims to conduct the feasibility study using the plasma focus facility as pulsed fast neutron analysis system that can be used for detection of explosive materials for threat reduction. This would require development of corresponding competence in pulsed fast neutron analysis (PFNA), where 14 (or 2.45) MeV neutrons from DT (or DD) plasma will be used as interrogating beam to produce gamma rays by (n,n’-g) reactions. In PFNA, explosive and contraband objects can be identified by observing signature ratios for gamma ray yields from key elements found in them. The overall objective of this proposal is to make contributions to the world’s Fusion Research using a novel high energy dense plasma focus which also has potential to contribute to Singapore’s national security issues
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Ó Rajdeep Singh Rawat, Natural Sciences and Science Education, National Institute of Education Updated on 21 Jan 2005 Contact │ rsrawat@nie.edu.sg |
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