Riemann's Contribution to Flight and Laser Fusion

quantity of thermonuclear energy, "ifoptimally employed."The real yardstick in terms of measuringthe consistency of projectionsfor fusion research is to be found interms of what is predicted for the finalparameters of a power reactor. Nuckollsand Wood state: "Thermonuclearmicroexplosions producing on theorder of 10 7 to 10 9 (5 to 10 poundsTNT equivalent) are suitable for commercialpower production. . . . L[aserenergy] = 10 6 J." The latest laser fusionreactor designs, which consist of detailedstudies, project laser energiesof about 2 X 10 6 joules, and similartypes of pellet gains of 50 to 100.Bending FactsFurthermore, contrary to whatMetz reports, the inertial fusion programhas been able to stay prettymuch on schedule, despite majorbudget curtailments and numerousnew scientific problems. Efficientcoupling of laser energy to pellets hasbeen achieved for both the classifiedsoft X-ray and the unclassified directbeam approaches. Also, researchershave reached isentropic compression(that with no entropy change) of upto 100 times liquid density.The accompanying figures give theprojected status of the mainline inertialfusion program for 1976 and1981. The projection in Figure 1 waspresented to Congress in March 1976by Dr. John L. Emmett, director of theLivermore Laser Program. The resultspredicted for the Shiva laser havebeen achieved. The projections inFigure 2 are from the most recentlypublished review of the inertial fusionprogram, that of Dr. Gregory H. Canavanin the March-April 1981 issue ofFusion. As can be seen, Nova 2, theupgrade of the Shiva laser to higherpower levels, is predicted to go beyondbreakeven when completed inthe mid-1980s. The change in the projectiondate from the early-1980s isprimarily the result of inflation slowingdown construction.As for Metz's negative statementsabout the practicality of laser fusionreactor designs, Metz quotes not oneof the scores of detailed studies thathave been carried out over the pastdecade. The waste question, furthermore,is entirely spurious, since theamounts involved are small, and thetechnologies for waste exist today.And Teller and Bethe are both onrecord supporting a fusion-fission hybridsystem and have stated that thiscould be accomplished in a decade.As Fusion has consistently reported,it would be false to say that there areno basic scientific or technologicalquestions still to be answered in inertialconfinement research. In fact,the opposite is the case for inertial aswell as magnetic confinement. As fusionresearch has progressed over thepast decade, the number of unansweredbasic scientific questions hasincreased.This in no way undermines the contentionthat practical forms of fusionenergy generation can be confidentlypredicted as being within our grasptoday. The open-endedness of thescientific questions raised by fusionand plasma physics research actuallypoints to fusion's most attractive attribute:It can be continuously perfectedto more and more advancedforms of cheaper, cleaner, and moreefficient energy generation.Leading scientists and governmentprogram administrators have allegedthat the Science article may have beenthe product of direct collusion betweenMetz and the antiscienceforces who want to classify advancedscience and contain the kind ofbreakthrough developments thatwould permit economic and populationgrowth. Given the role of Metz'sprevious articles in Science that attackedthe magnetic fusion programat the same time that former secretaryof energy James Schlesinger wastrying to kill the program, such collusionwould not be surprising.It is also probable that the antifusioncampaign, including Metz's article,intends to impugn the credibilityof the inertial confinement scientistswithin the new Reagan administrationwho have an influential voice on crucialmilitary and technology decisions.—Charles B. StevensClassifyingScientific Progress:A Case ExampleThis exchange of letters is a recentcase example that demonstrates thechilling effect of classification on theadvancement of science and technology.Dr. Friedwardt Winterberg of theUniversity of Nevada's Desert ResearchInstitute in Reno proposed ina Dec. 2, 1980 letter to the Departmentof Energy Office of Inertial Fusiondirector, Gregory H. Canavan,that the DOE undertake a new andeconomical method to test inertialconfinement. His letter and Canavan'sFeb. 20, 1981 reply appear here in full.* * *Dear Dr. Canavan:The most critical question regardingthe feasibility of beam induced ICF[inertial confinement fusion] is not somuch the feasibility of the laser oraccelerator technology but the feasibilityof the high-density pelletcompression. Many scientists, like Dr.Teller (but also myself), feel uneasyabout the prospect to reach ~ 10 3times solid density by ablative implosion.But since the cost of the requiredlaser or particle beam accel-Fusion ReportOctober-November 1981FUSION 19