Dr. HIRSCH. To recapitulate for a moment, the Princeton device the duplication of the T-3-provides us an opportunity to touch base and gain experience on a plasma which we know is thermonuclear from their experience.

I would now like to turn to the ORMAK system at Oak Ridge National Laboratory. In its first configuration this machine is similar to the Soviet TM-3 device, with two very important differences. First, the magnetic design in the ORMAK device is as nearly perfect as is possible. The device uses a simple one turn coil. There are in effect no "lumps" in the magnetic field, whereas in the Soviet system this is not the case.

We have in the ORMAK almost perfect magnetic symmetry and with this device we can determine how important symmetry is to the operation of tokamaks. Magnetic symmetry will be important in the design of future experiments, because it has major effect on cost. In addition, the magnetic field in the ORMAK I is a factor of two higher than the field in the Soviet TM-3 device. Therefore the ORMAK I provides us an opportunity to test magnetic field scaling in the tokamak. One of the questions in tokamak research is how these devices scale with the various external parameters, such as the symmetry of the magnetic field, the size of the field, etc. The ORMAK I would provide some insight to this question.

Representative HOSMER. You did skip ORMAK 0?

Dr. HIRSCH. ORMAK 0 was an attempt to take an old quadruple device and modify it at low cost to make a quick and dirty small tokamak for tabletop experimentation-something to use "to get one's feet wet." As it turned out, the device did not operate in what Oak Ridge considered to be a reasonable fashion and the device has been dropped; it does not exist.

Chairman HOLIFIELD. What about the ALCATOR?

Dr. HIRSCH. May I finish on the Oak Ridge device for just a moment? There is another unique feature of the Oak Ridge device which I think is very noteworthy. The coil is a one-turn coil design unlike the many-turn coil configurations used in other devices. This permits us-at relatively low cost at a later time-to replace the first coil with a different coil to check the importance of aspect ratio scaling. In other words, we can remove this small coil and install a larger coil-one that has a larger opening but yet a smaller major diameter. This will give us an important point in terms of aspect ratio scaling of tokamak systems. Beyond that, we can envision other changes that can be relatively straight forwardly made on this machine that otherwise would require completely new machines.

The ALCATOR device was conceived at the Massachusetts Institute of Technology and has been reviewed by us. Its important featureits single most important feature is the fact that it will permit a much higher magnetic field than has heretofore been possible in any CTR device. As a matter of fact, it has the capabilities of going to 130 kilogauss-which is a factor of about 4 higher than the Soviets have utilized in their tokamak experiments and is considerably higher than we have utilized in experiments in this country. This high field opens a whole new regime of plasma operation. We know from the Soviet data that the performance characteristics of the tokamak

improve with increasing magnetic field. So, by going to a much higher magnetic field, we definitely expect a significantly more interesting plasma-higher energy, longer containment time, and so forth.

Representative HOSMER. Does this include the improvements that ORMAK I incorporated relative to the symmetry of the magnetic field, and so on?

Dr. HIRSCH. No, this will not. We are going forward in parallel in this case, as with all of these systems, rather than in series. ALCATOR will have a very good magnetic field design. It will have some ripple associated with the fact that a discrete coil configuration is utilized. I would say that the design of this device is in excellent hands, because it is being designed by the National Magnet Laboratory, which is funded by the Air Force, as I think you probably know. These people have many years of experience in the design of these particular magnets as well as many other magnetic configurations. We expect that the ALCATOR will get us into a new range of plasma operationone that has not been investigated before. It will also, of course, provide us more data on magnetic field scaling in tokamak systems. It brings to bear an experienced faculty at the Massachusetts Institute of Technology-one that has been engaged in plasma physics both at MIT and, during summers and sabbatical years, at the various national laboratories for well over 10 years. These people have a great deal of experience; a number of them have operated big machines in the past, and they have done a great deal of basic plasma physics work under the AEC. They have the diagnostic capability to study these plasmas in detail. As a matter of fact, the English experiment on Thompson scattering was pioneered at MIT a number of years ago. The next device is the Doublet II at Gulf General Atomic. This machine is the successor to the first tokamak system that we had in this country. The Doublet I was an attempt by the scientists at Gulf General Atomic to extrapolate beyond multipoles to a reactor. It utilizes the good features of multipoles and eliminates the bad feature of internal conductors to move toward fusion reactors from multipole research. They originally called this device the "Plasma Current Multipole." What they did in effect was to remove the internal conductors and replace them by currents in the plasma.

They came up with a configuration which they feel is very attractive, one which would allow higher relative pressure-higher beta if you would like-than is possible in tokamak. (One of the disadvantages of the tokamak is that it currently seems to be limited in beta to the order of a few percent.) Theoretical studies of the Doublet indicate it can achieve a beta of 10 to 20 percent-a value well within the reactor regime. Doublet I achieved a beta of 1 percent, which is a factor of ten higher than the tokamaks have thus far displayed. (Related correspondence follows:)

Mr. EDWARD J. BAUSER,

U.S. ATOMIC ENERGY COMMISSION,
Washington, D.C., February 11, 1970.

Executive Director, Joint Committee on Atomic Energy,
Congress of the United States.

DEAR MR. BAUSER: The Controlled Thermonuclear Research program has recently completed a review of a proposal from Gulf General Atomic on an improved tokamak concept-the so-called Doublet II. We hope to initiate fabrica

tion of this experiment in FY 1970 and wish to inform you of the background on this matter. The staff will be prepared to provide more details to you at the time of the authorization hearings on the Physical Research Program.

The Doublet concept was conceived by Dr. Tihiro Ohkawa in late 1967 as an outgrowth of their work on toroidal multipoles. A prototype of this system (Doublet I, a device fabricated at GGA expense) was operated in early 1969 and demonstrated the stability of the system. Although the experiment was limited in its operating parameters, it achieved a beta value (the ratio of plasma to magnetic pressure) of 1%, which is about a factor of ten higher than the largest value so far achieved in the Soviet tokamaks. The Doublet I represented the first U.S. tokamak-type experiment and occurred before the recent interest in tokamaks.

The Doublet II system is much larger than its predecessor and is designed to create and confine a collisionless plasma as opposed to the collisional plasma in Doublet I. If successful, this experiment would demonstrate stable, longtime plasma confinement of a plasma whose beta would be of the order of 10-20%, i.e., considerably higher than achievable in tokamaks. The total cost of the machine to AEC is estimated to be $350,000 of Major Device Fabrication funds and $230,000 of Capital Equipment funds. The remainder of the estimated $810,000 total cost will be borne by GGA. We hope to provide $140,000 of Operating funds and $76,000 of Equipment funds in FY 1970; the remaining funds would be provided in FY 1971. When the device comes into operation in July, 1971, it will replace the D.C. Octupole experiment and thereby not significantly affect the operating level at GGA. In addition to partial financial support, Gulf General Atomic has agreed to grant the Government full rights to the Doublet concept. If the Joint Committee would like additional information on this experiment, we would be most happy to provide it.

Sincerely,

R. E. HOLLINGSWORTH,
General Manager.

Dr. HIRSCH. The last tokamak which I would like to mention is the device at the University of Texas. Its purpose is to test turbulent heating as a means of raising the ion temperature in tokamak well into the thermonuclear regime. The physicists at the University of Texas have been involved in turbulent heating for many years and have an acknowledged expertise in this area. We are still in the process of reviewing this proposal. Therefore, I think that other than to say that it attacks yet another portion of the tokamak problem, I would suspect I ought not to say anything more.

We now are ready to move ahead on both the ALCATOR and Doublet II.

Representative HOSMER. As distinguished from what it might appear to be to a casual observer, there is some relationship among these various tokamak-type investigations you are now carrying on, and it is not a helter-skelter race by various geographical locations to get into the business?

Dr. HIRSCH. No, sir; it very definitely is not.

Chairman HOLIFIELD. What is the total cost of this tokamak program, Dr. Hirsch?

Dr. HIRSCH. The total cost we project for Fiscal Year 1971 for tokamak research is about $5.5 million. That would represent about one-third of our expenditures in the area of "Confinement Systems." Chairman HOLIFIELD. What was it last year?

Dr. HIRSCH. During this present fiscal year?

Chairman HOLIFIELD. Yes.

Dr. HIRSCH. I don't believe I have those figures with me, sir. It would be less.

Chairman HOLIFIELD. It would be less?

Dr. HIRSCH. Yes, because of course we are just getting underway with a number of these systems.

THE OUTLOOK FOR CTR

Representative HOSMER. Would you care to speculate how far along we are on the road to the Eldorado of limitless, almost free electric energy of the controlled nuclear fusion process?

Dr. HIRSCH. As you recall, Dr. Bishop had been projecting for years that he expected the scientific feasibility of CTR to be demonstrated by the year 1978. With the way things are developing at the present time, it could be much sooner. I say "could be much sooner" because we have now in our hands a number of very important developments which demonstrate that plasma confinement is not limited by some of the anomalous effects which we had previously observed and which we had to wrestle with for so long in the past. Nature is not against us in this work. As a matter of fact, it appears that all we have to do is be careful enough and do the right things. Indeed it appears we can go all the way to classical confinement in a number of plasma systems. If we can do this, in my opinion, we certainly can develop controlled fusion.

Representative HOSMER. At that point, 1978 or earlier, we could think of getting into the practical aspects of it?

Dr. HIRSCH. Yes, sir. What I was about to say was that at this point in time the people in the CTR community feel for the first time we are in a position to progress forward at a rate which is determined by the funding which is allocated to the program. We could not say this in the past.

Representative HOSMER. Do you believe that with proper funding this could progress and move ahead of the fast breeder development? Dr. HIRSCH. I would say with proper funding we could move forward very rapidly.

Representative HOSMER. That was not exactly a responsive answer. We will leave it there.

Chairman HOLIFIELD. Mr. Young?

Representative YOUNG. Mr. Chairman, I am glad to hear Dr. Hirsch say what he did about the advantage of studying turbulent heating at the University of Texas. I am familiar in general with their efforts down there. They are most enthusiastic about the opportunity that they have there. Actually, they are providing the facilities and AEC is going to provide the operation; is that correct?

Dr. HIRSCH. Yes, sir, that is their proposal. We understand that it is expected that this Friday the Board of Regents at the University of Texas will allocate $350,000 for the fabrication of the device which they expect to begin immediately. We also understand that the Texas scientists have obtained approximately $200,000 for 2 years from the Edison Electric Institute to help instrument this device.

Representative YOUNG. Thank you very much. Thank you, Mr. Chairman.

Chairman HOLIFIELD. Dr. McDaniel, we are going to put the rest of your statement in the record.

Dr. MCDANIEL. I think Dr. Hirsch has testified more eloquently than my written statement would have done.

Chairman HOLIFIELD. He is a very competent witness.

Representative HOSMER. He is quite a capable forensic physicist. (The statement of Dr. McDaniel follows:)

42-051 0-70-pt. 2

CONTROLLED THERMONUCLEAR RESEARCH

The goals of the controlled thermonuclear research program are to establish the basic laws of physics relevant to the confinement of thermonuclear plasma ; and to experimentally demonstrate the creation, heating and containment of a gaseous plasma suitable for the economic production of electric power. We estimate that the U.S. program represents approximately % of the total world wide fusion effort. A recently completed "World Survey of Major Facilities in the Field of Controlled Fusion" describes 187 plasma devices of which 38 are in the United States.

The achievement of useful controlled fusion energy requires that we (a) heat a dilute gas of fusion fuel to temperatures of hundreds of millions of degrees, and (b) contain it long enough (and at sufficient purity) for an appreciable fraction of the fuel to react. Plasmas above the ideal ignition temperature at densities needed for controlled fusion have been routinely produced for a number of years. The world research effort has been concentrating on how to adequately contain the hot plasmas. During the past year, plasma confinement has been obtained which is close to or above the minimum conditions needed for a fusion reactor in both open and closed confinement experiments.

The next step is to combine the necessary density, temperature, and containment time into a single experiment to demonstrate the scientific feasibility of fusion power. The recent results in the Tokamak T-3 reported by the Soviet Union are a major achievement in this direction. The Tokamak T-3 has a 4,000,000° C. plasma with a density of 5 X 1013 particles per cubic centimeter contained for %0 of a second. These results have been confirmed by a laser diagnostic team sent from the United Kingdom to the Soviet Union. In the area of open systems research in the United States the 2X experiment at LRL has achieved equally remarkable conditions. Its temperature is 80,000,000° C.; its peak density is 5 X 1013 particles per cubic centimeter and its confinement is very close to the classical upper limit.

Our September 4, 1969, letter to Mr. Bauser advised you of plans concerning initiation of tokamak research involving fabrication of a tokamak system at Oak Ridge National Laboratory and Conversion of the Model-C Stellarator at Princeton Plasma Physics Laboratory into a Tokamak. Since that time technical reviews of two additional proposals have been completed although no work has been initiated. These proposals involve (1) fabrication of an experimental device named ALCATOR which will be housed in the National Magnet Laboratory at MIT and (2) fabrication of an experimental device named Doublet II by scientists at Gulf General Atomic Corporation. A fifth proposal submitted by the University of Texas is currently under review. Each of these devices focuses on a different aspect of tokamak research. At Oak Ridge, a unique and flexible oneturn coil design is incorporated in a device called ORMAK. This is basically a model of the Soviet TM-3 experiment but provides significantly improved magnetic field design. The relatively inexpensive addition of a second coil will allow the exploration of low aspect ratio scaling without necessitating fabrication of a completely new device. Conversion of the Model C Stellerator, located at the Princeton Plasma Physics Laboratory, to a tokamak will provide the quickest means of obtaining an operating tokamak system in this country. We expect to significantly advance our knowledge of basic tokamak operations from this device. The MIT ALCATOR system has the capability of exploring a wholly new and interesting range of high magnetic fields i.e., to 130 kilogauss, a level about three times higher than achieved in the Soviet experiments. Opening this new regime of high magnetic fields is considered extremely important from both the experimental and theoretical points of view. The Doublet II offers a potential means of increasing the relative plasma pressure over ten times higher than that achieved in the Soviet experiments.

Research with tokamak devices represents but one facet of our low-beta toroidal research effort. In addition to tokamaks, multipole and stellarator systems are also under study. The simplicity, relatively low cost and flexibility of multipoles are such as to make them very attractive from both an experimental and theoretical point of view. For this reason we have emphasized work on multipoles and recent successes in understanding and long-time confinement have justified this choice. Moreover, confinement of plasma in stellerators in recent years has been improved beyond the anomalous or bohm level.

The initiation of research on tokamak systems represents an attempt on our part to bring balance to our low beta toroidal research effort and to exploit, if possible, what appears to be a quite fruitful line of pursuit at the present time.