Problems connected with particle extraction from superhigh-energy accelerators

With the purpose of increasing the operating efficiency of an accelerator with an energy of the order of thousands of GeV, main problems are considered which arise when extracting a proton beam from such an accelerator. Estimates of radiation heating of wire septum magnets, external targets and emergency absorbers under the action of the extracted proton beam are given. Probable measures on protection of the main equipment from radiation effects are discussed. It is shown that the best method of slow extraction is a resonance extraction with the use of the 3rd-order nonlinear resonance of betatron oscillations. High efficiency of this method, provided necessary measures are taken to protect superconducting elements in the extraction gap, makes it possible to attain an extracted beam intensity of the order of 1014 protons at an energy of up to 3000 GeV and extraction duration of 10-20 s. Fast extraction is proposed to be realized portionwise on the magnetic field plateau. In case of consequent multiple fast extractions alternating with slow ones it is convenient to use fast resonance extraction. Emergency beam extractions are also investigated