FAST BUNCH BY BUNCH EJECTION OF 3 TeV PROTON BEAM FROM UNK STORAGE RING

Construction of two high energy accelerator faci-lities- the UNK proton ring and the VLEPP electron-positron linear collider-in the same scientific centre (IHEP) opens the unique possibility for their co-operation in such experiments as, for instance, p-r colliding beams or acceleration in VLEPP linacs of pions generated by the extracted from UNK proton beam, and so on. To perform such experiments the time structure of the extracted proton beam should be matched with the VLEPP time structure. That could be achieved if the beam ejection is carried out one by one of stored in UNK bunches with 100 Hz repetition rate corresponding to that of VLEPP operation. With 200 MHz design frequency of the RF-system of the UNK storage ring there will be about 1.3. lo4 stored bunches of 1.5 ns duration separated by 3.5 ns. The presented solution of the problem of one by one extrac-tion of the proton bunches is based on the following approach. I. With account of the smallness of the transverse emittance oi accelerated proton beam the kickers could have a \‘ery small aperture and be placed outside the working aperture of the accelerator. 2.-4ccelerator straight section optics is to be orient-ed to the goal of bunch by bunch exraction. 3. To direct the beam into kickers aperture and to the wall of the Lamberstone type magnet a local distor-tion of equilibrium orbit should be made. 4. Kickers system is composed of many short counter travelling wave units separately fed by a couple of opposite polarity nanosecond pulses. 5. A special generator based on high current elec-tron beam commutator is used as a source for such pulses. As initial data for estimating, the following values are taken: Bunches repetition time 5 ns Spacing between bunches 3.5 ns Bunch duration 1.5 ns Accelerator acceptance (X anti Z) 6.9 mrn.tnrad Beam emittance (at the energy of 3 TeV) 0.0123 mm.mrad Beta-function 100 m Beam size (FWHM) I.11 m