betatron

Paper	Title	Other Keywords	Page
TUCHX02	Present Status of VEPP-2000	lattice, optics, luminosity, resonance	1
	D. B. Shwartz, D. E. Berkaev, A. N. Kirpotin, I. Koop, A. P. Lysenko, I. Nesterenko, E. Perevedentsev, Yu. A. Rogovsky, A. L. Romanov, P. Yu. Shatunov, Y. M. Shatunov, A. N. Skrinsky, I. Zemlyansky BINP SB RAS, Novosibirsk
	VEPP-2000 electron-positron collider has been completed in the Budker INP in 2007. First beam was captured in a special lattice with switched off final focus solenoids. This regime is used for all machine subsystems test and calibration as well as vacuum chamber treatment by synchrotron radiation with electron beam current up to 150 mA. Another special low-beta lattice with solenoids switched on partially was used for the first test of the round beam option at the energy of 508 MeV. Studies of the beam-beam interaction were done in "weak-strong" and "strong-strong" regimes. Measurements of beam sizes in the both cases have indicated beam behaviour similar to expectations for the round colliding beams. Also the first collider energy calibration at the phy-meson resonance was performed with SND detector. Since the end of 2009 VEPP-2000 started first experimental work with both particle detectors SND and CMD-3 at the energies of 500-950 MeV range with the lattice mode close to project.
	Slides
TUPSA029	Pickup Beam Measurement System at the VEPP-2000 Collider	injection, collider, controls, pick-up	101
	Yu. A. Rogovsky, E. A. Bekhtenev BINP SB RAS, Novosibirsk
	This paper reviews the present state of electromagnetic beam position monitors (pickups) at VEPP-2000 collider. It includes descriptions of position monitors, typical interfaces for these monitors and their system characteristics (resolution, stability, bandwidth and problems or limitations) are discussed. The paper also reviews several types of diagnostic measurements using beam position monitors which are useful in improving accelerator operations.
WEPSB014	Examination of Charged Particle Dynamics Through Employment of the Fourier Series	quadrupole, focusing, undulator, lattice	199
	O. E. Shishanin MSIU, Moscow
	In some papers we have considered an influence of the betatron oscillations on synchrotron radiation properties. To obtain uninterrupted solution for the Hill equation, in this case the transverse components of magnetic field were expanded in a Fourier series. This approach was usefully employed and posed problem was resolved in focusing periodic magnetic fields. Using this scheme, the equations of oscillations were also derived for storage rings. It was published in Proceedings of RuPAC2008. The procedure may even work for the various types of wigglers and undulators where the dynamics of particles can be described more precisely with regard to the concrete field inside a single magnet and their arrangement as a whole.
WEPSB024	An Increasing of Electron Beam Lifetime at Injection Energy in SIBERIA-2 Storage Ring by Regulating of Betatron Coupling	injection, coupling, electron, vacuum	218
	A. G. Valentinov, V. Korchuganov, Y. V. Krylov, Y. L. Yupinov RRC, Moscow
	A dedicated synchrotron light source SIBERIA-2 operates at 2.5 GeV with more than 100 mA electron current. An electron beam lifetime at this energy is defined now by vacuum conditions and exceeds 15 hours for 100 mA. The lifetime at injection energy 0.45 GeV is much lower – less than half an hour for typical current value 3–4 mA in singlebunch mode. An analysis of the lifetime value displayed a strong influence of Tushek effect in a presence of a horizontal aperture limitation. A dependence of the lifetime on different parameters (RF voltage, horizontal geometric and dynamic aperture, bunch current, betatron coupling value, electron energy) was analyzed. A betatron coupling regulation was recognized the easiest way to increase lifetime value at injection energy. It was done by two families of skew-quadrupole lenses. A 30–40% increasing of the lifetime was observed for different average values of a bunch current. Also a storing speed was raised because of slower decreasing of a stored current. The beam lifetime during energy ramping was also increased. It led to decreasing of current losses from 5-6% to 1.5–2% during energy rising from 0.45 GeV to 2.5 GeV.
WEPSB031	Transverse Bunch-by-bunch Digital Feedback for the VEPP-4M Collider	feedback, kicker, collider, controls	236
	D. P. Sukhanov, V. P. Cherepanov, V. V. Oreshonok, V. V. Smaluk BINP SB RAS, Novosibirsk
	The coupled-bunch instability is the base reason of the operating current limitation and even an beam loss at the VEPP-4M electron-positron collider. For suppression any excited transverse mode of oscillation of the accumulated beam, the transverse bunch-by-bunch digital feedback has been installed. The paper reports on the current design and status of the feedback system. The available diagnostic tools and latest operational results and beam measurements is given.