Riemann's Contribution to Flight and Laser Fusion

FEF Newsthe problems that have provokedplasma physics until now and posedenormous difficulties, suddenly disappearinto thin air.Question: At the time, people saidthat the magnetically isolated diode(MID) couldn't possibly work.When I first proposed this concept—thatwas 10 or 12 years ago—itwas completely ignored. A few yearslater, a very prominent man explainedthat magnetic isolation belonged inmore or less the same category as theperpetual motion machine. He declaredin a letter published in thejournal Nature that anybody who proposedsuch a thing should build aworking model, just like the patentoffice official who required the sameof inventors of perpetual motion machines.Since then, however, theprominent man has stated that thiskind of perpetual motion machinereally works, even though true perpetualmotion does not.Today MID is being used, for example,at Karlsruhe. They are alsopursuing inertial fusion there, and indeedwith ion beams generated byMIDs—albeit initially on a smallerscale than in the United States.technologies, which as allied technologiesfor fusion lead to decisive newperspectives, as with the productionof intense ion beams. In my opinionit will not be done simply with magneticisolation as such.What we need immediately aremagnetically isolated diodes that cangenerate ion beams of extremely highquality. The beams produced by thismeans are not so far of the desiredquality. So it has been not at all easyto focus on a tiny spot.produce fusion than heretofore imagined.Question: In the Federal Republic,not only is there no increase in investmentin fusion, but resources arebeing cut back, as for example atGarching. What do you think of thissituation?Basically, we should not recommendcutbacks, since that wouldmean dispensing with the know-howof this high-powered technology, andQuestion: That brings us to anothertheme. In the Federal Republic verylittle is being done in the field ofinertial fusion. Do you think moreshould be done, and why has so littlebeen done until now?In the mid-1950s there was a debateover what course fusion researchshould take, organized and led byProfessor von Weizsacker's administration.At that time it was decidednot to enter the field of inertial fusion,but to concentrate solely on magneticfusion. The state of inertial confinementtoday thus reflects a decisiontaken very early, but which may yetbe reversed, as we see in Karlsruhe.Question: How in your opinionshould research in this field be carriedforward?I would say that we should puttremendous emphasis on these newMembers of the Fusion Energy Forum organizing in Munich. "They aredefinitely contributing a great deal to the formulation of a positive energypolicy."A laser beam is a beam of higherquality; sunlight or the beam of aflashlight represents only a poor qualityby comparison, since unlike lasersit cannot be focused on a point. Wemust do research on the focusing ofion beams to extremely fine dimensions.If we succeed here, then weshall have completely new perspectivesand unforeseen breakthroughs,which will make it much easier todispensing with the experts who havea wealth of knowledge about it. Andin financing particular projects, greatemphasis should be put on the latesttechnologies, as in the project underwayat Karlsruhe. There must be amultitude of approaches underway—say, 10 to 100 times as many as now.Then the Federal Republic wouldachieve importance on a world scalein this area, much as the Federal Re-56 FUSION October-November 1981 FEF News