RUPAC2012 - List of Authors (Kurakin, V.G.)

Paper	Title	Page
TUPPB017	Multy Frequency Stored Energy RF Linac	350
	V.G. Kurakin, P.V. Kurakin LPI, Moscow, Russia
	Due to beam loading, accelerating gradient in rf linac is reduced in time if the energy acquired by charged bunches is not compensated by external generator that feeds the linac. Since the bunch energy gain in this mode of operation correlates strongly with bunch number, the energy spectrum of total bunch train might be corrected in order to suppress this additional spectrum widening. This spectrum control might be achieved with the rf cavity that operates at frequency shifted relative the main one in such a way, that any new bunch sees the cavity field in the appropriate phase correlated with bunch number. The first bunch traverses correcting cavity in field node while the last one in the phase, where the energy acquired by this bunch is equal to resulting bunch train energy spread arising from beam loading effect. Equations of beam - rf cavity interactions are derived followed by coherent beam dynamics exploration in the system described. Measures for suppression of non coherent bunches spectrum widening are suggested leading to insertion additional cavity excited at frequency shifted relative the main and adjacent frequencies. Direct Digital Synthesis technique is suggested as well to provide necessary frequencies and phase's correlations in linac. Advantages of proposed technique as well its possible applications are discussed.

WEPPD013	Inverse Compton Sources on the Basis of Electron Accelerators with Beam Energy Recovery	593
	V.G. Kurakin, P.V. Kurakin LPI, Moscow, Russia
	In inverse Compton Source, photons in Roentgen range originate from visible light laser photons scattered back on electrons with the energy of dozens MeV. Several schemes are suggested in the paper, beam energy recovery conception being the common idea of all of them. The first one is based on synchrotron with flat part of guiding magnetic field. Being accelerated, electron bunch interacts with photon bunch of free electron laser mounted on straight paths of the accelerator, then is decelerated during falling down period of magnetic field cycle, and extracted at low energy from synchrotron to absorb in beam dump. This measure decreases background that originates from bremsstrahlung of lost electrons inherent to classical schema with linear accelerator and storage ring. Two other schemes use superconducting linac that produces relativistic electron bunches which energy is recovered after use, free electron laser (FEL) driven by bunches from linac being used to produce photons bunches for source. In one scheme the same electron bunches are use to drive FEL and inverse Compton Source, while in the other one beam splitting technique is suggested. It is based on beam energy modulation with subsequent separation of successive bunches. The expected self excitation inverse Compton sources parameters are estimated followed by critical issues discussion for all schemes suggested.

Paper

Title

Page

Multy Frequency Stored Energy RF Linac

350

V.G. Kurakin, P.V. Kurakin
LPI, Moscow, Russia

Due to beam loading, accelerating gradient in rf linac is reduced in time if the energy acquired by charged bunches is not compensated by external generator that feeds the linac. Since the bunch energy gain in this mode of operation correlates strongly with bunch number, the energy spectrum of total bunch train might be corrected in order to suppress this additional spectrum widening. This spectrum control might be achieved with the rf cavity that operates at frequency shifted relative the main one in such a way, that any new bunch sees the cavity field in the appropriate phase correlated with bunch number. The first bunch traverses correcting cavity in field node while the last one in the phase, where the energy acquired by this bunch is equal to resulting bunch train energy spread arising from beam loading effect. Equations of beam - rf cavity interactions are derived followed by coherent beam dynamics exploration in the system described. Measures for suppression of non coherent bunches spectrum widening are suggested leading to insertion additional cavity excited at frequency shifted relative the main and adjacent frequencies. Direct Digital Synthesis technique is suggested as well to provide necessary frequencies and phase's correlations in linac. Advantages of proposed technique as well its possible applications are discussed.

WEPPD013

Inverse Compton Sources on the Basis of Electron Accelerators with Beam Energy Recovery

593

V.G. Kurakin, P.V. Kurakin
LPI, Moscow, Russia

In inverse Compton Source, photons in Roentgen range originate from visible light laser photons scattered back on electrons with the energy of dozens MeV. Several schemes are suggested in the paper, beam energy recovery conception being the common idea of all of them. The first one is based on synchrotron with flat part of guiding magnetic field. Being accelerated, electron bunch interacts with photon bunch of free electron laser mounted on straight paths of the accelerator, then is decelerated during falling down period of magnetic field cycle, and extracted at low energy from synchrotron to absorb in beam dump. This measure decreases background that originates from bremsstrahlung of lost electrons inherent to classical schema with linear accelerator and storage ring. Two other schemes use superconducting linac that produces relativistic electron bunches which energy is recovered after use, free electron laser (FEL) driven by bunches from linac being used to produce photons bunches for source. In one scheme the same electron bunches are use to drive FEL and inverse Compton Source, while in the other one beam splitting technique is suggested. It is based on beam energy modulation with subsequent separation of successive bunches. The expected self excitation inverse Compton sources parameters are estimated followed by critical issues discussion for all schemes suggested.