Burton Richter

It is a privilege to participate with this distinguished group in this forum on Research as an Investment. My perspective is that of a physicist who has done research in the university, has directed a large laboratory involved in a spectrum of research and technology development, has been involved with industries large and small, and has some experience in the interaction of science, government and industry.

Science has been in a relatively privileged position since the end of World War II. Support by the government has been generous, and those of us whose careers have spanned the period since World War II have, until recently, seen research funding increase in real terms. Support for long-term research really rested on two assumptions: science would improve the lives of the citizens, and science would make us secure in a world that seemed very dangerous because of the US/USSR confrontation. The world situation has changed radically, both politically and economically. The USSR is no more, and economic concerns loomed much larger as our deficit grew and as our economic rivals became much stronger. It is therefore no coincidence that federal support for long-term research peaked in the late 1980's (according to the National Science Foundation's science and engineering indicators) and only biomedical research has grown in real terms since that time.

The emphasis of this forum, the economic value of public investment in long-term research, looks at only one of the many dimensions in the impact of research on our society. In examining that dimension, it is important to understand the time scale involved. Product development, the province of industry, takes technology and turns it into things which are used in the society. Typically, these days, the product development cycle runs for three to five years. However, the research that lies behind the technologies incorporated by industry into new products almost always lies much further back in time--twenty or more years. I'd like to make four brief points and illustrate them with a few examples:

Telecommunications has been revolutionized by lasers and fiber optics, coming from research in the 1960's and 1970's. Lasers allow much higher communications speeds and much lower communications costs on cables made of tiny glass fibers that carry pulses of light instead of electricity. The theory on which the laser is based goes back much further to work by Albert Einstein in 1917 (he did work on atomic theory as well as relativity).

The Global Positioning System (GPS) that allows precise location of anything and anybody anywhere is based on ultra precise atomic clocks developed for research starting in the 1950's. The GPS system has a growing commercial importance in activities ranging from transportation to recreation.

The biotechnology industry is based in large measure on recombinant DNA techniques developed in the 1970's.

The explosive growth of the Internet--of such importance to commerce and information--is the result of four decades of work by a worldwide research community culminating in the development of the browser at the NSF's super computer center at the University of Illinois, and the development of the World Wide Web by the high energy physicists at CERN in Europe. As a high energy physicist I can only wish that we had been smarter, and, instead of having people type WWW when they want to surf the Internet, we had them type HEP. Perhaps we would have bigger budgets now had we done so.

The semiconductor industry's road map for ever more complex chips which increase the power of computers will, in about a decade, run into a regime of such small feature size that the behavior of even wires is not understood--quantum mechanical effects will become important.

The pharmaceutical industry is increasingly moving toward the design of drugs that interfere with the ability of pathogens to act. The designs are based on the detailed molecular structure of the pathogens determined by the structural biologists using the physicists' x-ray diffraction techniques.

The human genome project shows promise of developing the information to treat many health-related problems. It needs the development by the applied mathematicians of systems to allow efficient searching of huge data bases.

HIV protease inhibitors were synthesized by the chemists in the pharmaceutical industry based on the structure of HIV protease determined by the biologists using the physicists' x-ray diffraction techniques. Two of the drug companies finalized their formulations using the ultra-powerful x-ray beams from synchrotron radiation sources built by the accelerator builders. Today, about 35% of the running time on the Department of Energy's synchrotron radiation sources are used for this kind of structural biology.

The development of neural network computing algorithms to efficiently sort complex multi-dimensional data sets has it origins in the neurobiologists developing understanding of the structure of the brain.

Today, one of the most important treatment methods of cancer is irradiation with very high-energy x-rays. These x-rays are generated from small linear accelerators that are scaled-down versions of the machines made for nuclear physics and particle physics research. In the U.S. alone there are 3,000 such accelerators which treat more than 75,000 patients every day. There are 5,000 of these machines world wide. The first preclinical trial of this therapy took place in the 1950's.

Magnetic resonance imaging, the least invasive and most precise of the medical imaging techniques comes from the work of the chemists, mathematicians and physicists. The physics work goes back to 1938 when I.I. Rabi demonstrated nuclear magnetic resonance (NMR) on one atomic nucleus at a time. NMR in solids was demonstrated in the late 1940's. The mathematicians developed the two-dimensional Fourier transformer in the 1960's which cut the time required for a MRI scan by an enormous amount. Those among us who have spent 20 minutes inside one such machine should realize that without that mathematical breakthrough, a scan of a single patient would take more near to a day.

Patent applications in the United States are supposed to cite the prior art on which the particular patent is based. A recent study of patent applications from U.S. industry shows that 73% of the prior art cited comes from publicly-funded research. (F. Narin, K.S. Hamilton and D. Olivastro, The increasing linkage between U.S. technology and public sciences., To be published.)

A recent publication from the Brookings Institution and American Enterprise Institute looks at the impact of R&D on the economy (Technology, R&D, and the Economy,' B.L.R. Smith and C.E. Barfield, editors, 1996). In that book, Boskin and Lau studied the impact of new technology on economic growth and found that 30-50% of the economic growth in our society comes from the introduction of new technologies. Mansfield looked at the economic returns on research investment and found that they are 40-50% a year, though returns to an individual firm doing long-term research are much lower because it is not possible for an individual firm doing long-term research to keep all the potential benefits to itself.

Twenty and more years ago it was true that much new technology came from long-term R&D done in industry--one need only think of the glory days of Bell Laboratories, and the IBM, General Electric, and RCA research laboratories. However, the world economic system has changed and international competitive pressures have driven most of the long-term research out of U.S. industry. Today it is exceedingly rare to find an R&D program in industry whose time horizon is longer than three to five years to a product. We may regret this change, but it is real and it has come about because of deregulation and competition. If one's rivals don't spend money on research, in the short term they are going to have a better bottom line. Our economic system, indeed the economic system of all of the developed world, rewards short-term results and punishes those who don't do as well as their competitors. Thus, changes in society have made the federal investment in such long-term research much more important than ever before.

As I said earlier, today's high-tech industry is based on the research of yesterday, and that research was funded at a time when high-tech industry made up a much smaller fraction of our GDP than it does today. Since high-tech industry is a much larger fraction of GDP today than yesterday, and will be even larger tomorrow, the fraction of the federal budget invested in long-term research should also be larger. It is odd, and it is indeed dangerous for the long term, that the converse is true.

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Kosta Tsipis

In 1993 the U.S. State Department publication "The Hidden Killers, The Global Landmine Crisis" pointed out that there are about 120 million landmines still buried in 62 countries, potentially lethal remnants of armed conflicts over the past half century. Even though the combatants in these wars did not generally intend to harm the civilian population, abandoned landmines now kill or maim about 30,000 persons globally every year, 80 percent of them civilians.

Four hundred million mines were deployed between 1935 and 1996; of these 65 million were emplaced during the last 25 years. Various nations currently manufacture 7.5 million mines annually. In 1993 alone, according to U.N. estimates, 2~5 million mines were laid. In the same year, only 80,000 were removed. It is estimated that 100 million mines are currently stockpiled around the world ready for use.

Mines are durable objects that can remain active for decades. They are manufactured in large numbers by many nations including the U.S., Russia, China, Italy, and a hundred other suppliers. Their cost varies mostly between $3 and $15 each. A few may cost as much as $50 each. A mine usually consists of a casing (metallic, plastic, or even wood); the detonator, booster and main charge; the fuse; and sensors that range from a simple pressure plate or a trip wire to more sophisticated triggers. a collapsing circuit, pressure-distorted optical fiber, pneumatic pressure fuse, or various influence sensors -- acoustic, seismic, magnetic, thermal. The most common triggering mechanisms depend on pressure --5 to 10 kg of force -- applied on the top of the mine.

In addition to the human toll landmines claim in many, mainly poor, underdeveloped areas (in Cambodia an incidence of one amputee per 250 people has been caused by land-mine accidents). their negative effects are multidimensional. Landmines can, over the long term, disrupt normal economic activities, such as travel and transport, and deny land to farmers, in turn often causing malnutrition, hunger, or migration of agrarian populations to urban centers. Clearance is not only a safety issue, but an economic and social issue as well.

Demining operations differ sharply according to their purpose. Tactical demining, including minefield "breaching," aims at rapidly clearing a corridor for combat use through a minefield during battle, often in hours. "Tactical countermine" operations aim at the removal of most mines by military personnel from areas occupied by the military over days or weeks. "Humanitarian demining," the subject of this paper, involves the peacetime detection and deactivation over a considerable time of all mines emplaced in an area.

Because most mines have metallic casings or contain at least a few grams of metal (usually the firing pin and associated spring) the standard method of detecting mines either buried or hidden in overgrowth is a pulsed-induction eddy-current sensor that can unambiguously detect the presence of less than a gram of metal buried in nonmetallic soils to a depth of 10-20 cm. The pulsed-electromagnetic induction (PEMI) detector applies a pulsed magnetic field (T ;.5 msec) to the soil. The magnetic field propagates into the soil and diffuses into buried conducting materials. Eddy currents are induced in the conducting material which in turn produce an opposing magnetic field, (T ;200 5sec) as the applied field collapses. This opposing field disturbs the magnetic field produced by the detector. Perturbations in the detector field indicate the presence of a metallic object buried in the soil and are signaled by an audible sound. In effect, such detectors can detect reliably most of the smallest antipersonnel mines buried close to the surface. But they cannot detect totally, or almost completely, metal-free mines.

But this method suffers from a major disadvantage. Metal detectors detect not only mines but all metallic objects in the ground. Since quite often mines are laid in or near battlegrounds, metallic detritus -- shrapnel, bullets, pieces of metal, screws, wires, etc. -- causes a false alarm ratio often higher than 1000 to 1. Therefore, one of the major technical challenges in humanitarian demining is discriminating between false alarms and real mines.

Discrimination is currently accomplished in a very slow and dangerous fashion. The metal detector locates the buried metallic object to within five cm. Such detection takes about a minute per square meter of terrain. Demining personnel then probe the spot with a rod (metallic, plastic, or wood) about 20-25 cm. long to determine whether the detected object has the characteristic size and shape of a mine or is instead a mere piece of scrap metal. Depending on the soil type and condition (hardened, overgrown, etc.), discrimination by probe can take anywhere between two and 20 minutes. Once a mine is confirmed, it now takes about 10 minutes to dig it out, another 10 to explode it in situ (creating additional metallic clutter), and 10 more minutes for the de-miners to walk away from the explosion and back. All detected objects must be identified, or even dug up to assure that no explosives have been left in the ground.

This is clearly too time-consuming a method of discrimination. With current equipment and practices the process can take about 30 minutes for every metal detector signal. Moreover, the use of a probe to determine the nature of an object detected by a PEMI detector does not tolerate carelessness or boredom. The resulting average casualty rate for this work is one injured or dead deminer per 1000 mines detected. But rates as high as an injury per 100 mines have been encountered.

An additional problem is that many types of mines are designed and constructed with very little metallic content; some are completely metal-free. Metal detectors are of little use for these types of mines.

The laboriousness and riskiness of the current canonical method of discriminating mines from false alarms, and the existence of non-metallic, or low-metal content mines, have led to new technologies for use in humanitarian demining. Some of these are evolutionary versions of older approaches, some are quite novel. Here I describe first detection/discrimination methods, based on the mine's explosive contents, in its solid or vapor state:

A second class of detection technologies is based on the fact that a buried mine represents a discontinuity of dielectric or conductivity properties in the soil. This approach uses:

A third class of detectors, based on the differences in dielectric and diamagnetic properties of materials, uses:

These two types detectors detect and discriminate metallic and non-metallic mines respectively from the clutter presented by the ground and its contents.

An entirely different approach is to detonate mines without detecting them, instead of using detection and discrimination methods to locate mines (which are subsequently destroyed). This capital-costly "brute force" approach involves the use of vehicles equipped with rollers or treads that detonate anti-personnel mines by riding over them. Application of this is limited by terrain, the potential presence of antitank mines that can destroy the vehicle, and the difficulty of assuring that all mines in a given area have been destroyed (on uneven ground, the equipment may not apply the needed pressure everywhere).

Before either approach -- detection/discrimination, or brute force neutralization -- can be used, it is necessary to find, and determine the boundaries, of a minefield. Perhaps even more important is the confident identification of areas that are free of mines. This is the second major hurdle for humanitarian demining: developing rapid and efficient area search methods that will reliably determine the presence or absence of mines. Currently finding minefields and determining their approximate boundaries, as well as declaring areas as mine-free depends on visual observation, history of mine accidents or records of laid mine fields. Specially trained dogs or simple metal detectors are now used for area surveillance, a slow and risky method.

Several technological avenues are being followed in pursuit of a satisfactory method for remote, rapid, and reliable minefield detection.

Although this latter system was the most successful, it detected 99% of conventional surface-laid minefields but 66% of scattered mineflelds and 34% of minefields with buried mines.

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Thus, the problem of rapid minefield surveillance remains active, and is being addressed. A fusion of synthetic aperture radar and a hyperspectral imager data is showing good promise.

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To summarize the current state of humanitarian demining technologies: even though humanitarian demining has the dual advantages of time and low wage local labor ($1500 - $3000 per person per year), the currently used method is unacceptably slow, expensive., and dangerous. More important, it has only insufficient impact on the global landmine problem. More specifically, research and development in humanitarian demining needs to focus on four key areas:

Humanitarian demining technologies in the near horizon easily fall in two groups:

technologies approaching maturity that can be applied to increase the efficiency, speed, and safety of the labor-intensive current demining methods and those, more promising perhaps, that won't be ready for field operations for half a decade or so.

In the first category I include the Meandering Winding Magnetometer (MWM) and the various configurations of the Interdigitated Electrode Dielectrometer (IDED), the air knife (already in multiple uses), the explosive foam "Lexfoam," and a family of smart probes -- acoustical, thermal, or magnetic. In the second category I put the Nuclear Quadrupole Resonance explosives detectors, the rapid gas chromatograph, and the polymer-black carbon composites arrays to detect explosives vapors, and the family of remotely controlled, automated, or robotic vehicles that can perform both the detection and the neutralization of landmines. The wide area surveillance system that uses fused SAR/hyperspectral imager data naturally falls in this second group.

The MWM can reduce false alarm rates by a factor of 10 within a year or so and consequently reduce the time spent for detection to 5-20 sec/m2 of searched terrain. The air knife, which uses high pressure air as a hand-held probe to uncover buried metallic objects (false alarms or mines), could replace the simplest manual probes and speed up discrimination of mines from metallic fragments by a factor of 5-10 while improving safety at the same time. The use of Lexfoam ($9 per pound) to blow up the exposed mine would speed up the overall demining process by a factor of 2 to 5.

I shift now to the more advanced, more promising, but still untested in the field, detectors of explosives. Their advantage is clear: only mines and other UXO would trigger the detectors, fusing the tasks of detection and discrimination into a single step and therefore speeding up humanitarian demining decisively. One key advantage of this approach is that its efficiency of detection is not dependent on the metallic content of the mine. Plastic and low metal-content mines can be detected and identified as well as metallic ones.

Nuclear Quadrupole Resonance (NQR) depends on the fact that some atomic nuclei, such as nitrogen, are not spherically symmetrical, i.e. they possess electrical quadrupole moments. Depending on what kind of crystalline structure nitrogen nuclei find themselves in, their non-sphericity produces a unique set of energy states characteristic of the crystalline structure when precessed magnetically. Using this property, an explosive in its solid phase can be identified by its nitrogen absorption radio frequency lines. The explosive RDX can be readily detected by NQR, but TNT (the most common explosive in mines) and PETN are more difficult to detect. Although TNT detection will require longer detection times, many seconds, or even several minutes, NQR detectors can be used in discriminating mines from false alarms.

Two-sided nuclear quadrupole resonance explosive detectors have been tested in airports where they detect quantities of RDX comparable to those in a mine in six seconds. But applications of NQR to mine detection will first require the satisfactory solution of several problems: a) A way must be found to improve the detectability of TNT by exploiting more absorption lines, and by improving the electronics and the detector coil; b) The possibility of interference from stray radio signals at the relevant frequencies must be reduced; c) Some method must be found to deal with the inhomogeneities caused by the one-sided detection geometry that mine detection dictates.

The fact that trained dogs can detect mines unerringly indicates that mines emit vapors that characterize them uniquely, though this may depend on how long a mine has been buried. In all probability these are explosives vapors that either escape from the interior of the mine or come from traces of explosives "smeared" on the outside of the mine during manufacture, storage, or emplacement. It is not clear that these vapors emanate in real time from the mine or are vapors from particles that have stuck to dirt or vegetation directly above the mine.

Arrays of sensors, each with some specificity to a particular molecule or compound, are quite commonly used in the food and perfume industries to identify constituent compounds of the product. One such sensor is under development at Cal Tech. It uses physical-chemical properties of carbon-black organic polymer composites to develop vapor-sensing elements, each sensitive to different molecules. The collective response of an array of such elements can identify the type of vapor. DARPA is actively pursuing an array sensor for explosives detection intended of airport use, but probably adaptable for humanitarian demining work.