1 The Spinning Magnet Accelerator Cosmic CERNs and SLACs Robert Sheldon April 12, 2001

2 Space Plasma Cyclotrons

3/27  The "resonance ” condition for a cyclotron and the need for synchronization. u The maximum energy determined by maximum gyroradius of pole magnet u Center feed, rim exit. u Dipole=cyclotron u but NOT a betatron. The Synchro-Cyclotron

4/27 Drift Motion in B-field Gradients x

5/27 The Stochastic Dipole Cyclotron u Universe has dipoles. u Drift trapping more robust than gyrotrap because of edges. u Stochastically driven has power at all freq. u Adiabatic heating from inward diffusion (3rd invariant violation). u Adiabatic central heating--> escaping flux is cooler. u Rim feed, center exit. u The center is filled with the magnet, limiting the energy. u Diffusion rate slows near the center, limiting the power. PROCON

6/27 Insufficiency of the SDC  Although the radiation belts of the earth have 10 ’ s MeV particles, either GeV ’ s precipitate into the center, or keV ’ s adiabatically escape, cooling off. From a Mars vantage point, the Earth dipole is a weak source of keV particles and atoms. Nor does adiabatic heating explain power law tails. The Dipole is a better trap than accelerator.

7/27 MeV electrons 10/14/96

8/27 1 MeV electron in T96 Cusp

9/27 The Quadrupole Cusp u 2-Dipole interactions = Quadrupole. A Dipole embedded in flowing plasma creates a quadrupole cusp. u How likely? About like binary stars. u Quadrupole is both a drift+gyro trap. u Q is center feed, rim exit. Hi E escape. u Q has no center magnet permitting higher maximum energies. u Q is NOT adiabatic==> chaotic accel!

10/27 Quadrupole Cosmic Scales u Planetary Magnetospheres u Stellar Heliospheres u Binary stars u Galactic magnetic fields u Galaxy clusters u keV (Mercury) to MeV (Jupiter) u MeV as observed at Sun u 1-10 GeV u GeV ? u TeV?

11 Plasma Linear Accelerators

12/27

13/27 Parallel Electric Fields l Whipple, JGR Ne = Ni, quasi-neutrality  n kT e || E

14/27 Heuristics for Parallel-Efield

15/27 High Injection Density in Storms

16/27 Necessary Conditions u Inhomogeneous strong B-field such that grad-B drifts dominate over ExB –Dipole field! Ubiquitous u Source of hot plasma –Injected directly (accretion disks) –Convected from elsewhere (plasmasheet) u Spinning central magnet? u Result: –Rim feed, axial exit accelerator. Efficient

17/27 Herbig-Haro Objects: Stars with Accretion Disks HH30

18/27 Blazar and Schematic Jet

19/27 Quasar & Microquasar Jets Cygnus A 3C273

20/27 Quadrupole Electric Field: 1st Excited State of a Dipole B-field

21/27 Can SLAC power jets? u The maximum electric field of such a system is limited by 2nd order forces ((FXB) X B). Using some typical numbers for YSO for magnetic field strength, we get limiting energies of keV - MeV. u Applying same formula to quasar jets, we get ~1 GeV. Precisely the value that explains observations! u Q: What does a black hole magnetosphere look like? How does plasma affect equil.?

22/27 Preliminary Conclusions u Both mechanisms are topological –Ubiquitous. Scale to all sizes. u Quadrupole cyclotrons = 2 dipoles –Planets embedded in flowing plasma –Opposing magnetic fields, e.g. binary stars –Stars (galaxies) moving through a plasma background u Jets =accretion disks + spinning B-fields. –YSO, AGN, micro-quasars,Herbig-Haro –Earth has half an accretion disk=plasmasheet

23 The UAH Spinning Terrella Accelerator

24/27 Experimental Setup u Bell jar, oil roughing pump, HV power supply, Nd-B ceramic magnet u Needle valve used to control the pressure from mTorr u Simple

25/27 Negatively Biased Magnet

26/27 Arcs and Sparks

27/27 Characteristics of Discharge u KeV of Voltage u Discharge lasts 30 microseconds u Calculated milliCoulombs of charge u Estimated nF capacitance of magnetic field u In better vacuum (or collisionless plasma) potentials are limited by 2 nd order plasma drifts u Result: Space charge accelerator

28/27 Some References u Sheldon & Spurrier, "The Spinning Terrella Experiment", Phys. Plasmas, 8, , u Sheldon, "The Bimodal Magnetosphere", Adv. Sp. Res., 25, , u Sheldon, Spence & Fennel, "Observation of 40keV field-aligned beams", Geophys. Res. Lett. 25, , u All at: