Kristalline Ionen und Elektronenstrahlen
Prof. Dr. D. Habs (TU München, Sektion Physik)

For sufficiently cold ion beams a phase transition to a crystalline ion beam occurs. The ions of the beam are confined by the focussing potential and become ordered by their mutual Coulomb repulsion, when their relative temperature in the co-moving frame is small enough. Crystalline ion beams are the most brilliant beams of accelerator physics showing very unique properties like an extremely small emittance growth. We are investigating crystalline ion beams with the table top ion storage ring PALLAS at Munich to explore their properties and to scale the results to large storage rings and linacs. In PALLAS we store beams of laser cooled Mg+-ions at eV-energies. After our first publication on strings of ions (T. Schätz, U. Schramm and D. Habs. Letter to Nature / Vol. 412 / 16. Aug. 2001 /p. 717) we now succeeded to obtain bunched crystalline beams and larger three-dimensional structures. (Phys. Rev. Lett 87 (2001) 184801-1 and Phys. Rev. Lett., submitted.) Using a helical wiggler magnet in the laser cooling section also crystalline ion beams at large storage rings can be produced. Methods to produce crystalline electron beams by direct and indirect laser cooling will be discussed. As is known from chapter 14 task 12 of Jackson crystalline electron beams show a strong suppression of spontaneous synchrotron radiation.