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Home , Colliding beam fusion, Migma

Reactor Physics: General—II 787

                         Bogdan C. Maglich

California Science & Engineering Corporation, 16540 Aston St., Irvine CA. 92606 [email protected]

   (7) Invention of colliding beams1 (1972) presented a 2 challenging alternative to confinement of in plasmas ݊஽஽ሺʹǤͶ‡ሻ ൅ ܷ ՜ ʹܻ ൅ ʹǤͷ݊ ൅ ʹͳͷ‡ (8) (1960). Unique feature of colliding-beam machines, as opposed ݊ு௘்ሺ͸‡ሻ ൅ ܷ ՜ ʹܻ ൅ ʹǤͷ݊ ൅ ʹͳͷ‡ (9) to plasmas, is the long energy confinement time of colliding ்் beam systems from τE = 7 hours (Brookhaven) to 3 months ݊ ሺ͵Ǥͷ‡ሻ ൅ ܷ ՜ ʹܻ ൅ ʹǤͷ݊ ൅ ʹͳͷ‡ (10) (Fermilab, CERN) because they operate above the critical ஽் energy ~ 200 keV. Unlike random motion, colliding beams ݊ ሺͳͶ‡ሻ ൅ ܷ ՜ ܷ ൅ Ͷ݊ 4th generation: CHAIN FISSION are ordered systems and as such, subject to (1) magnetic U beam injection, mostly focusing forces, (2) external control by a combination of external periodic or aperiodic signals and (3) time average (11) neutralization via cloud oscillations. st with݊௙ሺ lowͳǤͷ‡ levelሻ 1൅ ܷgeneration ՜ ʹܻ ൅ ʹǤͷ݊injection ൅ ʹͳͷ‡ (1 – 2). This is a follow-up of paper #14125 at this Meeting describing a compact test breeder reactor IV that stored self-colliding deuterons of 725 keV with an energy confinement time of 24 s, resulting in copious production of and helium-3 isotopes. A quest is presented here of the feasibility of injecting a 4 MeV 238U+ beam3 in addition to 2 MeV D+ beam, into auto- collider Migma IV at 1.4 MeV4-6; this is equivalent to kinetic temperature of ~1010 oK. (Figs. 1 and 2). D+D catalyze fusion-fission chain until the operating regime is reached in 4th generation in 1 – 10 s (jump-start), as follows

1st generation: D+ beam injection (1)

ܦ൅ܦ՜ܶ൅݌൅Ͷ‡ (2) ଷ ܦ൅ܦ՜݊൅ ܪ݁ ൅ ͵Ǥ͵‡ 2nd generation: D+ beam injection (2) ଷ ܦ൅ܦ՜݊൅ ܪ݁ ൅ ͵Ǥ͵‡ (3)

ܦ ൅ ܶ ՜ ݊ ൅ ߙ ൅ ͳ͹Ǥ͸‡ (4) Fig. 1. D+D Auto-Collider Migma IV. Reactor chamber (a ଷ ܪ݁ ൅ܶ՜݊൅݌൅ߙ൅ͳʹ‡ (5) disc 1 m diameter, 0.2 m long) is sandwiched between pairs of superconducting NiTi weak focusing magnets (6 T on coil, ܶ ൅ ܶ ՜ ߙ ൅ ʹ݊ ൅ ͳͳǤ͵‡ 3.2 T midplane); V = 5 liter, baked 450 °C for 24 hours. 3rd generation: STRAIGHT FISSION Chamber interior is lined with fast reflector. See Fig. U and D beam simultaneous injection 3    ­ Van de Graaf + n's from reactions (2, 3, 4, 5) colliding with U. Accelerator injected 1.45 MeV, D2 ions into chamber center (6) where Lorentz plus collisional dissociation converted them into self-colliding orbits of 725 keV (Fig. 4). ݊஽்ሺͳͶ‡ሻ ൅ ܷ ՜ ʹܻ ൅ ʹǤͷ݊ ൅ ʹͳͷ‡

Transactions of the American Nuclear Society, Vol. 112, San Antonio, Texas, June 7–11, 2015 788 Reactor Physics: General—II

Fig. 2 Modifications of Migma 4 system for and auto-collider. Top view show U beam injection and fission fragments ejection perpendicular to it.

Note the high reactivities of Reactions (1, 2) and (6 – 10) of and , respectively, for head-on + colliding D +D+ିଶଶ at 1 MeV each.ିଶଵ σf b as En 1 MeV. Inൌ addition ͵ ൈ ͳͲ to powerͳൈͳͲ generation through fission, 4 otherۄߪݒۃ fusion reactions of the type D+3He b՜ͳ α +p+ 18՜ MeV and will generate directly convertibleଷ power. Contribution to energy balance from fusionܪ݁ ൅ and ܶ ՜ spallation ݀ ൅ ߙ ൅ neutrons ͳͶǤ͵‡ is not considered at this stage. Fission fragments, Y, charge multiplicity m = 5-10, are magnetically funneled into decelerator for DC conversion or modulated for microwave pickup (Fig. 3). The process takes place in UH vacuum, hence all 215 MeV produced, less the neutrons, is carried by charged particles.

Fig. 3. Conceptual design of direct electrostatic conversion     of kinetic energy of fission fragments and of non-fissioned U    + + ions via two electrostatic decelerators (arrows to left and Referring to Fig. 4, DC beams of D2 and U ions from right). Alternate method for direct conversion into RF power the same or two different accelerators are trapped in the is proposed in Ref. 8. Neutron reflector is indicated in green. center of a magnetic field B = 3.2 T by Lorentz and collisional dissociations and ionizations into self-colliding D+ and U + Unique feature of auto-collider, not obtained in the orbits, known as migma, and are stored continuously colliders, is the time-average neutralization of stored ion colliding with an energy confinement time τ~24 s (Fig. 5) in beam by the externally controlled oscillations of the electron vacuum 5x10-9 torr. With advanced vacuum technologies τ is cloud through the ions. Energy of the instability frequency is projected to exceed 1000 s. drained away by the imposed external frequency, thus

Transactions of the American Nuclear Society, Vol. 112, San Antonio, Texas, June 7–11, 2015 Reactor Physics: General—II 789

potential instability perturbation is controlled. Hence, the Injection of D2 beam of 1,450 keV, 0.5 mA, stopped at 8 sec; nuclear reaction time << τ i.e. stored beam depletes via non-linear stabilization done by electron cloud oscillations fission reactions much faster than via classical beam losses. through stored ions took over (Ref. 6).

Fig. 4. Reactor chamber (Diameter = 1 m) of Auto- Collider. Cross section through z=0 plane. A 1 MeV DC U2+ + and D2 beam, 10 A, is injected into central of symmetry of a Fig. 6. Electric power density m-3 assuming conversion focusing NiTi magnet Bz = 3.2 T, resulting in Lorentz and efficiency η = 1. F = no. of reactions involved. + collisional capture into U self-colliding orbits of 1 MeV. U : + orbits of trapped U migma ions; black circle: orbits of D  migma. Neutron reflector is indicated in green. While many issues were left moot of this SUMMARY, our conceptual physics quest provides ballpark numbers of While Migma IV used weak-focusing magnets, the the power density that might be produced: 100 - 1,000 proposed system must use strong focusing migma magnets MW/m3, in a disk shaped cylinder or cell, with obvious 9 designed for the purpose by Blewett to gain a factor of 100 ecological advantages over DT fusion reactors for which (i) in colliding beam density. direct conversion is unthinkable and (ii) thermal conversion Referring to Fig. 6, with 400 Amp D and U current, 100 of 14 MeV is an order of magnitude more cumbersome than 238 MW m-3 may be achievable with pure U in operating that of fission reactors (iii) 20 - fold energy release per regime. reaction and (iv) cost of T fuel per energy produced is 100 235 238 -3 If 1% U is injected together with U, 1 GWm may be times that of fission. This offers a reasonable incentive to achieved with 400 amp on operating regime, with F = 5 where conduct a simulation and engineering study. F = no. of Reaction (6 – 10). Key issue is to bring the system Compared to the Migma IV described here, to operating regime. 1. Strong focusing9 confinement should replace the weak focusing to gain the usual factor of 100-1000 in stored ion density (Fig. 7); and confinement time; 2. Stabilization by driven oscillations of electron cloud should include new development that took place in the field of election cloud stabilization of colliding beams; 3. Study of extraction of the electrically charged fission fragments and fusion products is required to determine conversion efficiency; 4. Design study of a multi cylinder fission engine by stacking cells.

Fig. 5. Measurement of ion energy confinement time τE = 24 4 s, in Migma IV. Amplitudes of radial and axial RF spectra produced by 725 keV self-colliding orbits of D+. േ

Transactions of the American Nuclear Society, Vol. 112, San Antonio, Texas, June 7–11, 2015 Transactions of the American Nuclear Society, Vol. 112, San Antonio, Texas, June 7–11, 2015

790 Reactor Physics: General—II

6. MAGLICH BC, CHANG TF: Stabilization by electron oscillations of stored ions at densities in excess of space-charge limit; Phys. Rev. Lett. 70, 299 (1993). Maglich BC, Menasian S.: U.S. Patent 4,788,024. 7. MAGLICH BC, HESTER T, SRIVINIVASAN M: Production of Tritium at zero cost in Blewett strong-focusing self-collider; Northern American conference, Sept. 29, 2013. 8. S. MENASIAN, Radio frequency direct conversion of Migma power Ref. 3. p. 209 9. BLEWETT J.P., Ring magnets in migma systems Ref. 3, p. 214; also Part. Acc. 34, 13 (1990). 10. MAGLICH BC, et al., “50 Years with Fission” Symp. Nat. Ac. Sci. (USA), p. 761 (89) Amer. Nucl. Soc. (Publisher).

Fig. 7. EXYDER7,9. Strong focusing fusion-catalyzed fission reactor with 8 injectors (1 – 8). RFQ accelerators; (compare with Fig. 4); ion sources not shown.

Note added in proof: It was pointed – out that the proposed system is highly proliferation resistant because the production of Pu induced by fast neutrons, which is the case here, has thousand times lower cross section than that produced with thermal neutrons. This paper opens the category of Colliding-Beam Hybrid Fusion Fission Reactor (CB-HFFR).

Acknowledgements: Thanks are due to profs. K. Shultis and R. Glauber , Dr. W. Fischer (BNL), and Dr. T. Hester for their constructive input.

*Patent pending.

 1. JOHNSON K, CERN intersecting storing rings (ISR); Proc. Nat. Acad. Sci.; USA 70, 619 (1973). 2. GILBERT FC, HECKROTTE W, HESTER RE, KILLEEN J, VAN ATTA CM: High energy molecular ion injection into a mirror machine; UCRL-5827 Controlled Thermonuclear Processes, UC20, TID-4500, Feb. 1960 TID 4500 (15th Edition). 3. W. FISCHER, Measurement of the total cross section of uranium-uranium collisions at √s=192.8 GeV. arXiv:1401.0213vl [nucl-ex] 31 Dec 2013 4. SALAMEH AL et al: Experiment with stored 0.7- MeV ions: Observation of stability properties of a nonthermal ; Phys. Rev. Lett. 54, 769 (1985). 5. MAGLICH B, NORWOOD J: Aneutronic energy, NIM A 271 1-288 (1988); Inst. Advanced Study Princeton Symposium, (North-Holland Physics Publishing Division).

Transactions of the American Nuclear Society, Vol. 112, San Antonio, Texas, June 7–11, 2015