Indiana University      Research & Creative Activity      April 1998 Volume XXI Number 2



Technology

by Harold Ogren

Science is a complex dance of experiment and theory. Great leaps of theoretical imagination punctuate the enterprise, but experiments pace the process. Experiments reveal the ways nature actually works. Most advances in experimental science are led by development of instrumentation. Examples of this interaction abound in astronomy, biology, chemistry, geology, and physics.

Astronomy really began with the invention of the telescope, which led to the discovery of our solar system. The development of large reflecting telescopes revealed our galaxy. The invention of radio telescopes led to the discovery of the remnant radiation left from the big bang.


Harold Ogren, Professor of Physics, Indiana University Bloomington, sits next to a mock-up of the straw-tube drift chamber that will be part of an experiment called ATLAS now being built in Geneva, Switzerland. The Bloomington group he leads is collaborating with more than 1,700 other physicists on the experiment. The ultimate goal of this experiment at the European Laboratory for Particle Physics (CERN) is to find the Higgs particle. This particle is the key feature in the standard model of particle physics and is responsible for producing the masses of all elementary particles. - credit

Biology was changed forever when the microscope revealed the complex world of cells and bacteria. The subsequent developments of instruments to view the very small, such as the electron and scanning electron microscopes, have revealed the cellular structure. Now DNA can be viewed and manipulated with the scanning tunneling microscope.

The study of chemistry began our exploration of the atomic world. Instrumentation to measure accurately the weights of substances, and the volume, pressure, and temperature of gases opened the door to our quantitative understanding of the atomic-molecular world. New instruments, such as nuclear magnetic resonance, mass spectroscopy, and gas chromatography, have become working tools for exploring our complex molecular world. Pulsed laser based instrumentation has expanded the small time scale domain, allowing chemical reactions to be viewed as they happen in time, and even to view molecular-level interactions.

Physics focuses on the world of atomic, nuclear, and subatomic forces and structure of matter. In the pursuit of this study, physicists developed many of the basics of modern instrumentation, such as lasers and semiconductors. These basics have been exploited in the wide range of instrumentation with application in all fields of science and in countless medical and commercial areas. The nuclear and subatomic realms have been explored with the inventions of Van de Graaff accelerators and cyclotrons (such as the one at Indiana University Cyclotron Facility). Immense particle accelerators that are now more than twenty kilometers in circumference can penetrate to the substructure of the proton and neutron. The largest research instruments that exist today are the particle detectors at such accelerators that are dozens of meters on a side, contain hundreds of millions of individual sensors, and collect data at rates over 100 gigabits per second.

Electronics is the key to all modern instrumentation. From the invention of the transistor in 1948 to the collection of many transistor circuits on an integrated circuit, each development has led to smaller and faster devices for measuring and controlling instrumentation. The massive interconnection of calculation and memory circuits into integrated circuits has resulted in the high speed computing and global computer integration such as the World Wide Web. We can expect technology to continue to accelerate in this area. New developments may come in unexpected directions, for instance analog computing may play a more significant role in the future. However, we can expect networked computing to be applied in all areas of life. In the sciences, these devices have allowed us to expand our time domain and to enhance our visual representations of the world.

The importance of instrumentation in science can be seen in the most recent Nobel prizes. Essentially every year for the past few decades one of the Nobel prizes has been given for the development of a technique or a particular device. In the last ten years, prizes have been awarded for atomic traps, making fullerenes, detecting neutrinos, and developing the PCR (polymerase chain reaction) method, particle detectors, the nuclear magnetic resonance technique, and atomic clocks. These prizes recognize the inventors of new technologies. However, the vast majority of all experimental Nobel prizes can be tied to the use of new technology that allowed a wider domain of measurement or a new level of sensitivity.


Larry Kesmodel, Professor of Physics, Indiana University Bloomington, stands in front of an ultrahigh vacuum system with a scanning tunneling microscope (STM) and high-resolution electron energy loss spectrometer. On the screen is an image of a faceted gold surface imaged with STM, a new microscopy used to examine the structure of surfaces with atomic-scale resolution. --credit

Instrumentation increases the sensitivity of the normal senses, quantifies our observations with precision, and expands the domains of these senses in time and space. The article about R. Kent Honeycutt, a professor of astronomy at Indiana University Bloomington, and the telescopes in Morgan-Monroe Forest exemplifies this development. He and his group have designed charge coupled detectors to replace photographic film, which in turn replaces a human eye. They have combined this sensing enhancement with robotic control of a series of telescopes that can more quickly and more regularly measure an array of stars every night. The results can be viewed and analyzed on a computer system that links the observatory to the university and spans the globe.

Shuming Nie, an assistant professor of chemistry at IUB, developed techniques for studying individual molecules. He has extended our normal visual observations to the molecular realm with both optical and atomic-force microscopes. The spectroscopy he does using laser excitation of molecules enhances our perception of color, but with greatly increased sensitivity and precision of measurement. Our normal interaction with the mechanical world is restricted to the size of our hands and the delicacy of our touch. These capabilities also can be expanded and refined for high-precision work. The atomic-force microscope and the scanning tunneling microscope can now manipulate single atoms. Nie and his group have extended their investigations to include the observation and measurement of DNA and the manipulation of genetic code.

The observation of the molecular structure of surfaces engages several IUB physicists. David Baxter and John Carini, both associate professors of physics, are collaborating with chemists to examine the texture and composition of freshly prepared surfaces. Surface physics studies carried out with electron beam bombardment by Larry Kesmodel, a professor of physics (see photo at left), include studying the structure with a scanning tunneling microscope. The STM is probably the best known nanotechnology device (technology to probe the molecular and atomic scale) used to view and manipulate individual atoms on a surface. It extends dramatically our domain of touching and moving. Atomic and even nuclear manipulation is required in the operation of the cooler ring at the IU Cyclotron and the particle detectors, such as described in the article about Vic Viola, distinguished professor of chemistry at IUB. Similarly, a new particle detector called Transition Radiation Tracker or TRT (see photo on the next page) will allow the observation of individual subatomic particles on a vastly expanded time frame. This device, being designed and constructed by the high energy physics group, can measure the position of millions of particles a second passing through it at the speed of light. It will be used in an experiment in Geneva, Switzerland.

In medicine and biology, the observation of cells is important for both diagnostic and scientific purposes. The microscopic world has been studied with a wide range of optical and electronic devices. Humans have a wonderfully developed three-dimensional vision system. The extension of this three-dimensional system to microscopy is possible with the confocal microscope. With this device Kenneth Dunn, an assistant professor of medicine at the Indiana University School of Medicine, has developed a technique using fluorescence probes to make detailed three-dimensional studies of the operation of a cell. Our domain of visualization has been expanded to include the three-dimensional virtual reality that can be created by the CAVE facility now in operation in the IUB computer science department.

Imaging of the body is key to accurate medical diagnosis for areas diverse as teeth and major body organs. Techniques range from magnetic resonance imaging (MRI) to ultrasonic scanning and the use fluorescent dye imaging. A new dimension of diagnosis is possible when precision measurements can be digitally stored and when fast and accurate comparisons with previous images can be processed. Computers will play an increasing role in medical diagnosis.

The university plays a seminal role in developing instrumentation, with the interplay of experiment and theory and with the interplay of teaching and research. The environment of free and open inquiry and the support of basic research fostered by the university can generate tomorrow's inventions and discoveries. Academic courses that excite students with the thrill of discovery and acquaint them with the latest technology offer the students not only exciting opportunities to develop into scientists, but also prepare them for employment after graduation. Students may become familiar with computers and software packages, or learn in the laboratory about interfacing a computer to a particular measurement device. For any particular experiment this is a means to an end--completing a measurement or carrying out an experiment--but the skill and experiences gained are valuable in the student's next step to employment.

The development of the Linda and Jack Gill Center for Instrumentation and Measurement will make this familiarity with the latest instrumentation even more accessible at Indiana University. Students will be able to work with faculty and staff on a wide range of instrumentation for applications in astronomy, biology, chemistry, cognitive science, computer science, geology, and physics. Links that are established with outside industry and government laboratories can focus these applications and ease the transition of research from the academic to the business world. Such connections have historically been much more numerous within the chemistry department, where much work is funded by private companies seeking basic research with possible future applications. Efforts such as those of Nie with assistance from industry and the National Institutes of Health and the research in spectrochemistry by Gary Hieftje, distinguished professor of chemistry at Indiana University Bloomington, are the rule not the exception.


David R. Rust, Senior Scientist in Physics at Indiana University Bloomington, moves the radioactive source while looking at signals from the straw-tube drift chamber module. This module is part of an experiment being constructed in Geneva, Switzerland, at CERN for operation beginning in 2005. --credit

An example of a research and industrial link in the physics department is LK Technologies, a company that was formed by Larry Kesmodel to develop electron energy loss spectrometers and scanning tunneling microscopes. The original instruments were produced to study surface effects, but the devices he developed with the help of the physics department machine shop were far superior to any commercially available, so a new business was born. Others in the physics department have set up production facilities for state-of-the-art high speed electronics, and formed connections with electronic companies to exploit circuits that have been designed for high energy physics.

In the next few decades, with the help of the Gill Center, we expect the university to become more involved with both government agencies and private industry to expand and accelerate research in instrumentation. We all can benefit from this enterprise. New instrumentation will be invented, new areas of research may open up, and perhaps a deeper understanding of nature will unfold. The dance will continue. dingbat


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