RESUMO
A low-energy positron beam is a unique probe of materials. In high-energy electron and positron storage rings it is possible to generate intense synchrotron radiation with a photon energy of 1-3 MeV by installing a high-field (8-10 T) superconducting wiggler. High-energy photons are converted to low-energy positrons by using a suitable target-moderator system. For an 8 GeV electron storage ring at a beam current of 100 mA, final yields are estimated to be about 10(8)-10(10) slow-e(+) s(-1) or larger depending on the moderation efficiency, with the size of the positron source 10(1)-10(2) cm(2). In the present work a wiggler magnetic system of 10 T is proposed. The main parameters of the superconducting wiggler are presented.
RESUMO
One of the main principles in electrodynamics, the change of magnetic field flux inducing an EMF in a wire coil, is applied for magnetic measurement. A scheme and the main parameters of the magnetic measurement system are described. The system was successfully used for magnetic measurement of a 7 T superconducting wiggler for LSU CAMD; results are presented.
RESUMO
A superconducting 7 T wiggler is under fabrication in a collaboration between Budker INP and LSU CAMD. The wiggler magnet has been successfully tested inside a bath cryostat and a maximum field of 7.2 T was achieved after six quenches. The main parameters of the wiggler and the method of the wiggler installation onto the storage ring are discussed.
RESUMO
The K-edge dichromography method was applied for preliminary bronchography test studies at the angiography station on the VEPP-3 storage ring. Images of xenon distribution over the test sample of Plexiglass were acquired. The obtained results demonstrate that thicknesses of xenon as small as 0.5 mm can be visualized.
RESUMO
A low-energy positron beam is a unique probe of Fermi surfaces, defects, surfaces and interfaces. In high-energy electron and positron storage rings (E > 6 GeV) it is possible to generate intense synchrotron radiation with 1-3 MeV photons by installing a high-field superconducting wiggler. The strength of the wiggler should be ~8-12 T. High-energy photons are emitted from the wiggler and converted to low-energy positrons by using a suitable target-moderator system. For an 8 GeV electron storage ring at a beam current of 100 mA, final yields are estimated to be ~10(10)-10(12) (slow-e(+) s(-1)) with the size of positron source ~10(2)-10(3) cm(2). The possibility of increasing the brightness of the low-energy positron beam is discussed. Advantages of using synchrotron radiation for producing positrons are pointed out. The effect of a superconducting wiggler on the stored electron beam is also discussed.
