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Argonne National Laboratory
The Campus
Argonne
National Laboratory is located a bit less than thirty miles from downtown
Chicago. It is an outgrowth of the University of Chicago Metallurgical Lab.
This was the team that produced the first ever, controlled nuclear chain
reaction, and set in motion the huge body of research and invention, which
came to be known as The Manhattan Project. Since it's inception and charter,
Argonne has gone off in a number of different directions. The machines here are also a rare and unique national resource. As such, this site needs to be managed, and it’s resources conserved. You can do things here that can be done nowhere else in the world. Scientists, researchers, and industry wait months, and even years, to get some time on some of these machines. Thus, though the lab is open, it is only open to the extent that the facilities can be used to advantage. So the committee sees to it that a team looking for new ways to make high strength polymers is not kept waiting while dad burns things in the Advanced Photon Source, to impress the kids.
In order to make use of the facilities, and to get time on the
machines, a proposal must be submitted. The committee reviews all proposals,
and determines their
suitability, merit, and viability, before rendering a decision. The
committee also determines how much user time a given proposal will be
granted on a machine. With this being one of the world’s premier research
facilities, and with a list of researchers waiting to get time here, every
hour spent on one project, is an hour that another, or several others, must
be deferred. So the resources here must be carefully marshaled. About a
third of all proposals submitted are rejected, for various reasons. Still,
this is the nation's lab --- our lab. It is ours to use, provided we can
justify the expense to our fellow taxpayers. Some pretty interesting things
have been studied here, and by some pretty surprising people.
So how does a sixteen-year old high school girl come up with the money to pay for this? For that matter, how does a forty or fifty year old research scientist do so? Well, one of the interesting things about the way in which this lab is run, is that you only pay, if you refuse to publish. Now there are many reasons that an individual, or corporation may wish to be discreet about what they discover here. It may be that a certain project will give a company a competitive edge in the market place. In such a case, where the researcher wants to keep findings secret, and not publish, Argonne collects a fee. So for those who wish to extend the boundaries of human knowledge, publish papers, and share their work, use of the facilities is free. The grounds and physical layout of the facilities are very much like a cross between a university campus, a park, and a suburban neighborhood. This 1500 acre pastoral setting is very pleasant, consisting of a series of lab buildings, halls, administrative offices, and service buildings, set among woods, fields, rolling hills, and curved drives. The whole facility is set within a forest preserve, in which rare white deer may sometimes be seen. Argonne is associated with the University of Chicago, and in many ways is an extension of that campus, even to the extent that there is regular shuttle service between Argonne, and a bus stop on Ellis Street in the Chicago campus. Appropriately, the shuttle stops near the South Side Chicago sculpture, which marks the spot of the first ever nuclear reactor.
Actually, Argonne differs subtly from a standard college campus.
There is a security gate, regular security patrols, and not all parts of the
campus are open to all visitors. There are also security warnings, and
flyers posted in some of the more, well traveled sections of the facility.
There is still government work going on here, and there is always the threat
of terrorism, not to mention theft of nuclear materials. A more typical
concern is that of industrial espionage. Many industry secrets are
discovered and perfected here, and these have some real value to their
developers, and to the competition. Remember that these users do not make
their work public, and thus must pay for the use of the facilities here. It
would not do to have privileged, hard earned, and valuable information
compromised, particularly after it had been paid for. Argonne has an electron microscope facility, one of the few neutron accelerators in the world, a cutting edge computing center, and a biocontainment laboratory, as well as numerous mechanical, chemical, nuclear, and high-energy labs and facilities. Six of these are operated as national scientific resources, in conjunction with the U.S. Department of Energy. Looking down the list of apparatus available for researchers, I couldn’t even recognize the functions of some of these devices, as listed on the Argonne web site. The sheer variety of work being done here is staggering. The Argonne Leadership Computing Facility features a 445-teraflop IBM Blue Gene/P, one of the most powerful computers in the world. Recently, Argonne has developed a system for getting a 100mv per meter, energy gradient in a particle accelerator. These devices are commonly able to generate only 20mv per meter, so this development holds great promise for greatly reducing the cost and size of future accelerators, or possibly greatly increasing the power of present day models amenable to modification. Besides the wide variety of work being done here, there is a wide variety of institutions and researchers active at the labs. There are researchers from all over the world, though most are from the U.S., Since this is a national laboratory. Besides industry, government, and academia working together, there is also collaboration between experts in a number of different fields. You may find biologists, chemists, and physicists working together, and it has become increasingly common to see people working outside their disciplines, sometimes well outside.
Argonne has around 3000 employees, of which
roughly 750 are professors. It is, in many ways, a self contained little
community. It has a newspaper, heating and generator plants, named streets,
and it’s own system of street addresses, and even a hotel and restaurant.
Argonne Guest House is where you stay, if you are a visiting researcher. The
156 room hotel is modern, and has most of the expected amenities, including
high speed connections to the labs, so that obsessive experimenters can lay
in bed and watch their projects. It also has a world class restaurant. For
less discriminating tastes, there is a cafeteria. The public is actually
invited to dine in the Argonne Guest House dining room. The kitchen is run
by a world class chef, and the prices are quite reasonable. You will also be
surrounded by interesting people, and interesting talk.
Taking the TourWhat follows is a mere description of one day's tour. It is not a description of Argonne National Laboratory. The place defies description. Even the people who work there, including our guide, admit that they can not grasp all of what goes on here. Places like this are the reason that today is not like yesterday, and tomorrow will be still more different. During our tour, we lightly touched upon only three, of the many directions that the research here is taking. A brief summary is below; but each subject will be shown in more detail on it’s own page. As of this writing, tours are offered on Saturdays, with a morning and afternoon tour being scheduled. Prospective visitors must register ahead of time. This can be done via the Argonne website (http://www.anl.gov/), or by phone. Tours meet at the visitor center, just outside of the entry gate. All visitors must have badges, provided at the gate, and these badges must show at all times. Cameras are allowed, though there may be certain areas (like control rooms), which may not be photographed. Light is pretty good in most areas, for the aspiring photographer, though it can get a bit dark around some parts of the ATLAS machine. The tour will last about three hours. Special tours may be arranged, to highlight special interests, though these are dependant upon finding a willing guide. Still, it happens. The people here love what they do, and enjoy showing the place off. It is not unheard of for a researcher to highlight related areas of the lab. The way to get such a tour, is to see who works in the field that catches your interest, and then contact that person directly, and ask for a tour. Every five years, Argonne has an extensive open house.
Reactor Science
This is
where Argonne got its start, as an outgrowth of the Manhattan project.
Initially, there was only one type of nuclear research. All nuclear research
was weapons research. After the war, it was thought that all of the energy
locked up in the atomic nucleus could also have some peaceful uses to which
it might be put. At the same time it was considered desirable to continue to
improve, and develop nuclear weapons. Scientists knew what the energy
potential of the nucleus was, and realized that the first crop of nuclear
weapons were grossly inefficient, in addition to being larger, heavier and
more delicate than need be the case. A different approach was needed, for
both fields of development, so there was a branching of nuclear research. In contrast to the early days of
nuclear science, with researchers leaning over tubs of radioactive salts,
and reactors built of bricks under stadium grandstands, the post war nuclear
scientist was very safety conscious. Our guide related experiences of being
at a reunion, and seeing a bunch of the old hands, now in their seventies,
or eighties, laughing about how they should all be dead by now, due to the
unsafe handling of nuclear materials back in the early days. Still, a few
did die, the most famous being Harry K. Daghlian, Jr. to be followed within
a year by Louis P. Slotin. In both cases, a simple slip was all it took. New
safety standards were soon put in place, requiring that all nuclear
assemblies be handled by remote control from a quarter mile distance. These deaths were caused by criticality accidents. This is an event where a sample of a fissionable substance is unintentionally made to go critical. The two incidents in question show just how easy it is to kill yourself when dealing with these materials. In the second case, two halves of a plutonium sphere, were kept separate by a screwdriver blade, as they were brought closer and closer. The blade slipped, and they were allowed to touch, making the assembly instantly critical. The first case was even stranger. This was a criticality experiment, where a sphere of plutonium was slowly lowered into a series of enclosures made of neutron reflecting materials. Again, a slip of the fingers was all that was required, and the sphere was dropped, just for a moment, into the enclosure. It instantly went critical. In each case, surviving witnesses proclaim that a blue flash, and a wave of heat passed through the room. This was a huge release of energy; but was not an explosion, in the usual sense of the word. There was no overpressure. Instead the energy was released as a combination of gamma rays, neutrons and other particles. The blue flash was not from the plutonium itself, but rather the ionization of the surrounding air by the radiation given off, so that it was the air that glowed, rather than the plutonium. Witnesses to the events also relate that the ball of plutonium seemed to be enveloped in a blue glow, almost like an incandescent blue fog. Strange stuff, and nothing to be playing games with, which is still another reason that there is such an emphasis on security at the places in which it is handled. There have been other nuclear related deaths since; but none at Argonne. Researchers have lost their complacency, and have become very aware of the dangers of their work. Even latter on, there was still the occasional accident, in the nuclear power industry, and a few near disasters in the military. It has been years, decades even , since any serious nuclear mishaps have occurred in the United States. This is not the case with the Eastern Bloc however. The Eastern Bloc nuclear program, as is typical of dictatorships, had shown less concern about the welfare of it's subjects, than about cost and expedience. The Soviet Union is gone now, crushed under it's own weight; but the former Soviet bloc countries are still saddled with much of the residue of the old empire. Part of this legacy is the electrification of large sections of the old eastern bloc, by graphite moderated reactors. There have been a number of nuclear accidents, the details of which have been made public, and many more about which the details were suppressed. The most famous of these was Chernobyl. The reactor here was a graphite moderated reactor, much like the nuclear pile, built by Fermi. Only a few such were ever built in the United States, and all of these were built very early in the nuclear program. The advantages of this type of reactor are that it is cheap, and fairly simple to build. No such reactor has ever been used here to generate power. This is because these reactors are quite dangerous. The graphite bricks in this reactor are quite able to catch fire, if they get too hot. Filling cavities in these bricks with uranium pellets, and allowing the whole pile to grow hot enough to heat water to drive turbines is a disaster waiting to happen. Still, graphite moderated reactors are cheap, easy to build, and fast to put into service. Even today, the Eastern Bloc continues to use such reactors, despite constant warnings from Argonne, and from other experts in nuclear power. As a sort of a compromise, Argonne experts are allowed to help manage and moderate (no pun intended) the risks of operating this particular type of reactor. The Chernobyl disaster was not a nuclear disaster, by the way. The explosion which took place there was purely chemical, as result of gases building up in the smoldering graphite bricks. While it is possible to safely operate such a reactor, there is just too little scope in their operation, for even the smallest error to occur. As with the experiments by Slotin, and Daghlian, one little slip is all that it takes for a disaster to occur. The most recent reactor designed here at Argonne is the IFR (Integral Fast Reactor). This type of reactor is being used in France, and Japan; but not here in America. It is about thirty times more efficient than the standard reactor designs. This means thirty times the power, from a given quantity of fuel, and one thirtieth of the waste. As a side effect, the nuclear waste produced in these plants is quite a bit less deadly, and less long lived, than that from conventional plants. A single such plant was built here, and then shut down. No new ones have ever been constructed. This was a great, and unfortunate, victory for the anti nuclear forces. Without the IFR, we have something like 40 years worth of usable nuclear fuel left. With it, and with no other technical changes, we have something like 1200 years worth. Using the IFR, with some minor changes to allow for the conversion of U238, and possibly thorium, we have millions, if not billions of years worth of power. With such a source assured for such a length of time, we could maintain and extend our civilization, our wealth, and our exploration. Eventually fusion, or some other better source will be found. In the meantime, we will no longer have to consider the options of reducing our quality of life, ruining the environment, and utilizing huge tracts of land so that we can burn food, in the form of corn derived ethanol, for fuel. Ironically, we are presently burning nuclear materials from old Soviet warheads, which we bought after the collapse of the Soviet Union. No new nuclear plants have been built since the eighties, another victory for the anti nuclear forces. This may soon change, however, as new legislation has been passed, to streamline the process, and make it a bit more reasonable. This is just in time. Our newest reactors are over twenty years old, and our oldest are twice that age, and more. These were designed for perhaps a thirty year lifespan, and so have already been running past their design life. They have also been running harder than was initially intended, in order to make up for reactors which have been shut down. It can be hoped that we have not waited too long. The loss of 20% of our power capacity would be catastrophic. Argonne came up with the answer over twenty years ago, with the design of the IFR. It remains to be seen if we have the wit to make use of it.
These resonators operate at radio frequencies. The frequency given is
97 MHZ though this can be adjusted, not only system wide, but from resonator
to resonator, in order to tailor the system to the weight and charge of the
particular atoms being accelerated. The 62 individual Superconducting Split
Ring Accelerators are able to impart up to 15% of light speed onto the
particles in the ion stream. Energies as high as 17 MeV are possible.
Advanced Photon
Source Calling the Advanced Photon Source an X-ray machine would be like calling The Grand Canyon, a big hole in the ground. In both cases it may seem that the differences might be only in degree; but like comparing a rowboat to a cruise ship, it seems that quantity has a quality all it's own. Technically, this is an electron accelerator; but here the electron beam is only a sort of a bit of the overhead, and is never used directly for any experiments. The accelerated electron beam is only here to provide X-rays. The X-rays are produced, by making the electrons in the beam wiggle. This has been a sort of a side effect of accelerators as long as they have been used; but the Advanced Photon Source is designed to enhance this effect. One big enhancement is the capability of providing high energy X-rays at a steady output. The beam is constant, for hours, days, for weeks --- however long it is operated, between shutdowns and servicing. Previous to the development of the APS, this was unheard of, in accelerators. The traditional accelerator would inject electrons into the main ring, and use them until they ran out, with the bean growing weaker and weaker. Eventually, the beam would be too weak to be usable, and would be discarded, and a new beam started. A beam operator at Argonne found a way to keep the beam at a steady energy. This technology, like most technologies at Argonne, was shared, and now most accelerators are able to provide beams of steady power. An interesting aside, about the sensitivity of this machine, was related to us by our guide. There are a number of magnets used to focus the beam, in addition to those, which accelerate the particles. Initially, these magnets were all set manually, and could be adjusted to tweak the machine, for best performance. Ideally, the beam will always be centered in the beam tube. Technicians noticed that the beam would sometimes wander, which should not have happened. They also noticed, to their surprise, that the wanderings of the beam followed a definite pattern. The beam would go around the tube, in a 28-day cycle. Like the world’s oceans, they were being affected by the gravitational pull of the moon. The beam of the Advanced Photon Source has a tide. These systems are automated now, so the variance is compensated for; but the tide is still there. So to what use do you put such a beam? Well, you certainly don't use it to X-ray medical patients. Putting a human in front of such a beam would be an instant death sentence. Medical X-rays are typically produced by charging electrons up to around 100 kev, and colliding them with a thin metal plate. This process is only about 2% efficient. By comparison, the injector of the APS accelerates electrons to around 450 mev (4500 times that of a medical X-ray machine); but this is only the injector. The main accelerator imparts 7 gev to the electrons. This is about a sixteen fold increase over the injector, and about 68,000 times the energy used to generate medical X-rays, bringing the electrons in the beam up to about 99.999999% the speed of light; but even this is not the whole story. The APS is considerably more efficient than your basic medical X-ray, and can produce a beam which is quite a bit more brilliant, per EV than anything in your doctor's office. In addition, the beam has about 25% coherency, giving it some of the qualities of an X-ray laser. Once again, though, the question might be asked: What do you do with such a beam? the main use of the APS is to look at things that are very small, and to look at them in great detail. This machine is capable of such detail, that users can see the shape of a molecule, or of a crystal lattice. Properly used, it will even show the various stages of chemical reactions, as they occur. |