Research Needs for Magnetic Fusion Energy Sciences - US Burning ...

More documents

Recommendations

Info

2. With information from action 1, construction of a new FRc experiment will be central to understanding scaling to high-s conditions. basic plasma parameters impose clear requirements for achieving s ≥ 10. For low collisionality, a variable separatrix radius up to 1 m and poloidal flux of 20-50 mWb will be required to confine 10-20 kev energetic ions in the desired thermal-s range. high current (~10-50 amp), medium energy (20-40 kev) neutral beams will allow a significant fraction of the current to be carried by energetic particles. Flexibility with respect to shaping is also important for addressing stability. transport studies will be combined with the high-s studies since cross-field transport in FRcs is related to the ratio of electron drift velocity to ion thermal velocity (g d ). experiments and calculations show anomalous resistivity decreasing sharply as g d is reduced below unity. in FRcs g d ~ 2.3/s, so high-s FRcs will naturally have g d < 1. high-energy axis encircling ions will also affect transport, so studies of high-s stability and transport are synergistic. density fluctuation measurements will require laser scattering diagnostics. 3. The outcome of actions 1 and 2 will be used for a proof-of-principle scale experiment that will integrate high-b operation with boundary plasma control. integration of Elements development of the scientific and technological basis for economical fusion power through minimal applied field unifies the elements of this Thrust. The configurations cover a space of parameters that extends from large paramagnetism to extreme diamagnetism, over varying degrees of magnetic shear, and from moderate to large b. While device-specific development paths should be pursued, the common activities listed earlier will foster greater collaboration. The three configurations need similar diagnostic developments, and profile and boundary control. collaborations will increase the versatility of simulation capabilities and the reliability of numerical predictions. Finally, system studies will help quantify engineering tradeoffs. Other Scientific benefits The study of low external field configurations has strong ties to the areas of space, solar, and astrophysical plasmas. magnetic self-organization in RFPs and spheromaks is related to dynamo, which is considered important for the generation of interstellar and intergalactic fields. current collimation and the mhd stability of stellar and astrophysical jets are analogous to basic properties of the RFP and spheromak. magnetic reconnection and associated ion heating are also important in these configurations, as they are in solar and space plasmas. With their robust stability, FRcs with large ion gyro-radii (low-s) have potential application beyond steady confinement schemes. additional information gained from existing and planned facilities of this Thrust can be useful for high energy density laboratory plasma (hedlP) programs such as magneto-inertial fusion. it will also influence the development of plasma thrusters for space propulsion. over the last two decades, low external field research in the Us has largely benefitted from and contributed to fusion science efforts at our major research universities. its exploratory nature fosters creative thinking and motivates scientific discovery in fusion science. it will continue to have important educational value throughout the iteR era. 386
Connections to Other Thrusts • For the RFP, three-dimensional shaping for improving confinement by externally inducing quasi-helical states is an activity in Thrust 17. aspect ratio optimization to enhance bootstrap current and to influence mode coupling is related to Thrust 16. • The integrated data analysis described earlier is critical for experiments such as iteR, where diagnostic access is extremely restricted and the need for validated data is extremely high. turbulence and fast ion diagnostics are required for measurement of transport mechanisms in all magnetically confined plasmas. (Thrusts 1 and 6) • Predictive modeling that integrates microturbulence with macroscopic dynamics for low-field devices requires strong electromagnetic effects, including changing magnetic topology. it will rely on sufficiently general development from Thrust 6, and validation requires diagnostic capabilities that measure turbulence in low-field conditions. in turn, efforts for Thrust 18 will broaden the parameter space of predictive simulation capability. • low recycling wall development is a potentially breakthrough area for all three low-field configurations and is an important activity in Thrust 11. • ct injection of fuel and momentum is a potential method of controlling the profiles of density, fusion heating, and rotation for iteR and demo. (Thrust 13) • solenoid-free formation and current drive are strengths of the ct program and will continue to contribute to low aspect ratio tokamak development. (Thrust 16) 387
Page 1 and 2:
Research Needs for Magnetic Fusion
Page 3:
Research Needs for Magnetic Fusion
Page 7 and 8:
ExEcutivE SuMMaRy nuclear fusion
Page 9 and 10:
Magnetic confinement magnetic confi
Page 11 and 12:
The thrusts span a wide range of si
Page 13 and 14:
eactor, most heat comes from fusion
Page 15 and 16:
thrust 18: achieve high-performance
Page 17 and 18:
confinement is measured by the so-c
Page 19:
PART I: ISSUES AND RESEARCH REQUIRE
Page 22 and 23:
ReneW Organization: Themes The stru
Page 24 and 25:
22 Table 1. ReNeW Thrusts Address R
Page 26 and 27:
ON PREVIOUS PAGE Nonlinear simulati
Page 28 and 29:
extended operation phase. The optim
Page 30 and 31:
Figure 2. Alpha particles can cause
Page 32 and 33:
Figure 3. Spectrogram of the time-v
Page 34 and 35:
Do the alpha particles couple to th
Page 36 and 37:
• improved understanding of the e
Page 38 and 39:
most relevant to iteR. Recent obser
Page 40 and 41:
H-mode access: access to the h-mode
Page 42 and 43:
although present-day devices have m
Page 44 and 45:
estimates indicate that it will be
Page 46 and 47:
can enter the plasma core and dimin
Page 48 and 49:
ent drive alone cannot account for
Page 50 and 51:
Figure 10. Control involves the ele
Page 52 and 53:
to operation of iteR. solutions for
Page 54 and 55:
• identification and stabilizatio
Page 56 and 57:
Disruption prediction accurate pred
Page 58 and 59:
Figure 12. The application of non-a
Page 60 and 61:
ion losses, a quantitative predicti
Page 62 and 63:
due to incompatibility of the measu
Page 64 and 65:
agnostic measurements of critical p
Page 66 and 67:
quires assessment of when potential
Page 68 and 69:
suggesTions for furTher reading 1.
Page 70 and 71:
miTigaTing TransienT eVenTs in a se
Page 72 and 73:
ON PREVIOUS PAGE Nonlinear simulati
Page 74 and 75:
increasing power density and pulse
Page 76 and 77:
of recent accomplishments that have
Page 78 and 79:
ity limits have been maintained. in
Page 80 and 81:
highly risky in such an environment
Page 82 and 83:
proximity-coil-based magnetics is ~
Page 84 and 85:
will dominate the external sources
Page 86 and 87:
The barrier gradient is generally l
Page 88 and 89:
interaction with plasma boundary an
Page 90 and 91:
itER-at aRiES-i aRiES-at b n (%) 3.
Page 92 and 93:
and morphology, are needed. new mea
Page 94 and 95:
field and temperature fluctuations
Page 96 and 97:
large-scale process control problem
Page 98 and 99:
tics. integrated control methods fo
Page 100 and 101:
ing and design include computationa
Page 102 and 103:
dated in the corresponding structur
Page 104 and 105:
These requirements are applicable t
Page 106 and 107:
• assess computationally, on test
Page 108 and 109:
Research Requirements for Electron
Page 110 and 111:
the launcher design is partly “tr
Page 112 and 113:
tunities and goals for a few of the
Page 114 and 115:
front layers of the field magnets c
Page 116 and 117:
R&D Strategy a number of critical t
Page 118 and 119:
formance burning plasmas are covere
Page 120 and 121:
CreaTing prediCTaBle, high-performa
Page 122 and 123:
magneTs JosePh mineRvini, massachus
Page 124 and 125:
ON PREVIOUS PAGE Design of the ITER
Page 126 and 127:
to stabilize deleterious plasma mod
Page 128 and 129:
longer than the (solid) thermal equ
Page 130 and 131:
Promising new ideas have been devel
Page 132 and 133:
to handle 10 mW/m 2 , and elms with
Page 134 and 135:
• liquid surface PFc operation in
Page 136 and 137:
integrated effort that includes fun
Page 138 and 139:
Taming The plasma-maTerial inTerfaC
Page 140 and 141:
138
Page 142 and 143:
ON PREVIOUS PAGE Design of an ITER
Page 144 and 145:
trons in the breeding blanket. Thes
Page 146 and 147:
Safety and Environment • developm
Page 148 and 149:
plasma and gas to the scrape-off la
Page 150 and 151:
gaps: need to select and test the t
Page 152 and 153:
• neutron and other radiation tra
Page 154 and 155:
emphasis on modeling and expertise
Page 156 and 157:
gap: Current understanding of stren
Page 158 and 159:
Research needs critical research ne
Page 160 and 161:
• Proposing integrated safety des
Page 162 and 163:
• techniques and instruments to a
Page 164 and 165:
Qualifying DEMO Components Possible
Page 166 and 167:
• developing the design of an eff
Page 168 and 169:
harnessing fusion power Theme memBe
Page 170 and 171:
168
Page 172 and 173:
ON PREVIOUS PAGE Reconstruction of
Page 174 and 175:
Figure 1. Configuration space for t
Page 176 and 177:
of 40%.) localized instabilities (t
Page 178 and 179:
• Reduction of spheromak magnetic
Page 180 and 181:
ment, but also micro- and macro-ins
Page 182 and 183:
esearch requirements • evaluate t
Page 184 and 185:
the banana regime, low turbulent tr
Page 186 and 187:
in stellarator discharges with ohmi
Page 188 and 189:
• investigate how demountable coi
Page 190 and 191:
tion using a central solenoid is al
Page 192 and 193:
functions, edge flows, and edge neu
Page 194 and 195:
Development of predictive capabilit
Page 196 and 197:
Edge localized modes (ELMs): edge l
Page 198 and 199:
theory predictions for alfvén inst
Page 200 and 201:
coils, to permit replacement of the
Page 202 and 203:
stand the relative roles of long-to
Page 204 and 205:
Table 1. 202
Page 206 and 207:
primarily electrostatic, in the cas
Page 208 and 209:
to be important in present experime
Page 210 and 211:
PLaSMa bOunDaRy intERaCtiOnS The ex
Page 212 and 213:
calized field errors that can cause
Page 214 and 215:
needed Theory, Computation, Modelin
Page 216 and 217:
Scientific Issues and research requ
Page 218 and 219:
esearch requirements new facilities
Page 220 and 221:
small, concept exploration experime
Page 222 and 223:
tRanSPORt: DEtERMinE unDERLying tRa
Page 224 and 225:
esearch requirements analysis of ne
Page 226 and 227:
nEEDED FaCiLitiES nEEDED tHEORy, CO
Page 228 and 229:
connections Between Research Requir
Page 230 and 231:
opTimizing The magneTiC ConfiguraTi
Page 232 and 233:
230
Page 234 and 235:
232
Page 236 and 237:
234
Page 238 and 239:
Proposed actions: • Prioritize bu
Page 240 and 241:
3) as planning matures for the rese
Page 242 and 243:
that have high impact, that benefit
Page 244 and 245:
could have an impact on the identif
Page 246 and 247:
The Us fusion program is well posit
Page 248 and 249:
Mitigation of disruptions in the ev
Page 250 and 251:
elevant plasmas for very long pulse
Page 252 and 253:
and stability, and mitigation requi
Page 254 and 255:
• control alpha heating feedback
Page 256 and 257:
heavy ion beam probes (already in u
Page 258 and 259:
alpha particles (ash removal). mode
Page 260 and 261:
• determine minimum heating power
Page 262 and 263:
Research should focus on developing
Page 264 and 265:
estal structure need to be coupled
Page 266 and 267:
• sufficient heating with little
Page 268 and 269:
Proposed actions: Short-term: begin
Page 270 and 271:
Demonstrate active control of the p
Page 272 and 273:
Demonstrate burn control and contro
Page 274 and 275:
Develop the means for and demonstra
Page 276 and 277:
Medium-term: Test and optimize full
Page 278 and 279:
276
Page 280 and 281:
• Recruit, train and support dedi
Page 282 and 283:
With this information in hand, phys
Page 284 and 285:
to carry out the validation program
Page 286 and 287:
and new devices could be designed w
Page 288 and 289:
• high-field sc magnets for stead
Page 290 and 291:
Element 2 — High current conducto
Page 292 and 293:
Element 7 — integration of conduc
Page 294 and 295:
many other scientific fields are be
Page 296 and 297:
• based on these assessments, pro
Page 298 and 299:
systems include neutral beams, ion
Page 300 and 301:
The Us d-t facility, studied in 1b,
Page 302 and 303:
300
Page 304 and 305:
• design and implement innovation
Page 306 and 307:
the controlling instabilities and s
Page 308 and 309:
cross-field transport in the pedest
Page 310 and 311:
The modeling of near-surface plasma
Page 312 and 313:
310
Page 314 and 315:
• build large-size test stands wh
Page 316 and 317:
trol of the energy, impact angle, a
Page 318 and 319:
ties that take advantage of simple
Page 320 and 321:
ased materials development with adv
Page 322 and 323:
introduction Thrust 11 addresses th
Page 324 and 325:
technology is now evolving to inclu
Page 326 and 327:
The elements of a thrust to develop
Page 328 and 329:
The plasma facing components in a d
Page 330 and 331:
to demonstrate that steady and tran
Page 332 and 333:
mum of nuclear activation and prese
Page 334 and 335:
332
Page 336 and 337:
introduction harnessing fusion powe
Page 338 and 339: each Thrust 13 element includes the
Page 340 and 341: Figure 3. System concept for perfor
Page 342 and 343: equirements. Understanding the fuel
Page 344 and 345: • Use a combination of existing a
Page 346 and 347: chemical interactions between the s
Page 348 and 349: dose fusion-relevant environment wi
Page 350 and 351: Use a combination of existing and n
Page 352 and 353: 350
Page 354 and 355: evaluate, through advanced design a
Page 356 and 357: at the time when the demo design is
Page 358 and 359: 3. Computational analysis managemen
Page 360 and 361: Materials and Components: Fuel Cycl
Page 362 and 363: • employ energetic particle beams
Page 364 and 365: • develop and validate theoretica
Page 366 and 367: • develop new diagnostics for int
Page 368 and 369: • increase sustained noninductive
Page 370 and 371: 368
Page 372 and 373: Proposed actions: 1. conduct two qu
Page 374 and 375: The key areas in which new knowledg
Page 376 and 377: • exploration of high-temperature
Page 378 and 379: • availability of high-power radi
Page 380 and 381: 378
Page 382 and 383: • study FRc stability at small io
Page 384 and 385: techniques for integrated data anal
Page 386 and 387: 4. based on the outcome of actions
Page 390 and 391: 388
Page 392 and 393: aCROnyMS anD abbREViatiOnS (continu
Page 398 and 399: aPPENdix c: tHEME WoRKSHoPS tHEME W
Page 400 and 401: 14. d.l. humphreys, Active Realtime
Page 402 and 403: tHEME 2: CREating PREDiCtabLE HigH-
Page 404 and 405: 43. t.W. Petrie, White Paper: Some
Page 406 and 407: tHEME 3: taMing tHE PLaSMa MatERiaL
Page 408 and 409: 37. e.J. strait, J.c. Wesley, m.J.
Page 410 and 411: 20. s.a. maloy and e. Pitcher, Fusi
Page 412 and 413: tHEME 5: OPtiMizing tHE MagnEtiC CO
Page 414 and 415: 39. P.W. terry, a. boozer, J.s. sar
Page 416 and 417: don coRRell, lawrence livermore nat
Page 418 and 419: GeoRGe mckee, University of Wiscons
Page 420 and 421: tony tayloR, General atomics RichaR
show all

Research Needs for Magnetic Fusion Energy Sciences - US Burning ...

Create successful ePaper yourself

Delete template?

Save as template?