RuPAC-2010 - List of Keywords (feedback)

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feedback

Paper	Title	Other Keywords	Page
TUCHZ01	Accelerator Complex U70 of IHEP: Present Status and Recent Upgrades	extraction, proton, synchrotron, ion	27
	S. V. Ivanov IHEP Protvino, Protvino, Moscow Region
	The report* overviews status of the U70, accelerator complex of IHEP-Protvino comprising four machines (2 linear accelerators and 2 synchrotrons). Particular emphasis is put on the recent upgrades implemented since the previous conference RuPAC-2008. * On behalf of the U70 staff

TUPSA032	The TNK Beam Position Monitor System	single-bunch, storage-ring, pick-up, insertion	110
	E. A. Bekhtenev, G. V. Karpov, E. Shubin BINP SB RAS, Novosibirsk
	New second generation synchrotron radiation source TNK is being built in Zelenograd, Russia. The new FPGA-based beam position monitor (BPM) system for TNK has been developed and produced in BINP. The BPM system requirements for second generation light sources are not as severe as for the third generation light sources. Nevertheless the system is able to perform turn-by-turn measurements and has micron level accuracy. The TNK light source is intended for work both in multiple and in single bunch mode. In the second case the charge of one bunch can achieve the value of 60 nK result in high peak voltages at BPM electrodes. Design features of the BPM system, its parameters and testing results are presented in this paper.

TUPSA036	Advance of the Marginal Oscillator	resonance, induction, impedance, electron	122
	V. G. Ryzhov MRTI RAS, Moscow
	The advance of the transistor marginal oscillator (TMO) circuits are considered. The various TMO circuits, the features of their functioning and the simple NMR magnetometers based on them are reviewed.

WEPSB021	RF Cavities HOM Longitudinal Instabilities at SR Source Siberia-2 in KCSR	storage-ring, injection, synchrotron, electron	210
	V. I. Moiseev, V. Korchuganov, A. Vernov RRC, Moscow
	The electron beam parameters stability and its lifetime depend on the resonant excitation by RF cavities HOMs. The instability rising links with the temperature change, the sequent tune of RF cavities and the synchrotron tune change. Besides that the different intensity bunch distribution along the orbit influences strongly on the instability appearance. For the instabilities study and their identification the spectrum analyzing is used. The results of instabilities study at SR source Siberia-2 is presented in the report.

WEPSB026	Digital Longitudinal Feedback Systems in Synchrotrons	synchrotron, damping, acceleration, kicker	224
	V. Zhabitsky JINR, Dubna, Moscow Region
	The stability of a beam in synchrotrons with a digital longitudinal feedback system is treated. A longitudinal feedback system is required in synchrotrons to stabilize the high intensity beams against longitudinal instabilities and to damp the phase injection errors of a bunch. Damping rates of the digital longitudinal feedback system in dependence of its gain and delay are analysed.

WEPSB031	Transverse Bunch-by-bunch Digital Feedback for the VEPP-4M Collider	betatron, 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.

WEPSB032	Transverse Feedbacks in the U70 Proton Synchrotron of IHEP	kicker, pick-up, damping, controls	239
	O. P. Lebedev, N. A. Ignashin, S. V. Ivanov, S. E. Sytov IHEP Protvino, Protvino, Moscow Region
	To handle the adverse effect of transverse injection errors and resistive-wall instability in the U70, two frequency-band-separated feedback circuits are routinely employed. The first one is a narrow-band (around base-band DC) local end-to-end-analog circuit terminated by an electrostatic kicker. The second is a wide-band band-pass circuit with a variable (–10% ca) digital delay line and low-level DSP units and an electro-magnetic kicker. Both the circuits were subjected to a deep renovation during the recent 5 years, which provided a better control over transverse motion of the beam. The paper reports on technical solutions implemented, problem-oriented R&D studies, and beam observations.

WEPSB039	Upgrade of the U-70 Proton Synchrotron Extracted Beam Lines Control System: Multiple Access and Data Presentation	controls, synchrotron, proton, quadrupole	260
	V. Alferov, Y. Bordanovsky, V. Lagutin, I. Lobov, A. Lutchev IHEP Protvino, Protvino, Moscow Region
	Equipment under control consists of about 130 Magnet dipoles and quadrupoles, with power provided by 112 power supplies (PS). Each PS is controlled by an individual AD based controller; since a number of used magnets is not stable and exceeds the number of available PSs, commutation is used. Controllers are connected to a front-end computer by means of four CAN field buses. The software for these controllers is tuned to a specific type of the PS and a specific inductive load of the magnet. The server Dell PowerEdge T710 is used for PS control with multiply access from several client workstations which controls PSs for particular Beam Line. All client workstations along with server and front-end computer are connected together using a dedicated LAN. The server grants different users a different permissions to control their "own" PSs only. All measured data are stored into an archive, the archiving step is about 4 seconds. The operating commands are stored into the archive too, this feature gives a helpful possibility to reveal all users actions in case of measurement misunderstanding. The software is based on NI Developer Suit Core and MS Office Web Components packages.

THCHX01	Beam Tests of the LHC Transverse Feedback System	kicker, pick-up, damping, injection	275
	V. Zhabitsky JINR, Dubna, Moscow Region W. Höfle, G. Kotzian, E. Montesinos, M. Schokker, D. Valuch CERN, Geneva
	A powerful transverse feedback system ("LHC Damper") has been installed in LHC in order to stabilise the high intensity beams against coupled bunch transverse instabilities in a frequency range from 3 kHz to 20 MHz and at the same time to damp injection oscillations originating from steering errors and injection kicker ripple. The LHC Damper has been also used for exciting transverse oscillations for the purposes of abort gap cleaning and tune measurement. The LHC Damper includes 4 feedback systems on 2 circulating beams (in other words one feedback system per beam and plane). Every feedback system consists of 4 electrostatic kickers, 4 push-pull wide band power amplifiers, 8 preamplifiers, two digital processing units and 2 beam position monitors with low-level electronics. The power and low-level subsystem layout is described along with first results from the beam commissioning of 16 power amplifiers and 16 electrostatic kickers located in the LHC tunnel. Results of beam tests of the power and low-level subsystems are summarized.
	Slides

THCHC05	A Family of Twenty-Amperes Power Supplies for Multipole Correctors for Accelerators and Storage Rings	power-supply, controls, storage-ring, impedance	306
	O. V. Belikov, V. R. Kozak, A. S. Medvedko BINP SB RAS, Novosibirsk
	This report presents three types of direct current supplies that have been developed at BINP SB RAS. Their maximum current values are ±20А with output voltage up to ±50V, ±100V, ±150V. The power supplies are intended for steering electromagnets of colliders and storage rings, operating as the Synchrotron Radiation sources. The power supply channel occupies a 3U subunit crate (432355133mm) of the "Euromechanics" standard. Specialized units are used to control and monitor the power supplies through the CAN-bus interface. The output current accuracy is of the order of 100ppm for 10 hours of operation. This report presents experimental characteristics of the power supplies.
	Slides

THPSC017	High-voltage Source with Output Voltage up to 60kV with Output Current up to 1A	controls, cathode, impedance, power-supply	357
	D. V. Senkov, I. A. Gusev, A. S. Medvedko, A. Yu. Protopopov, D. N. Pureskin BINP SB RAS, Novosibirsk
	The presented report contains the description of high-voltage source with output voltage up to 60kV and output current up to 1A. The source consist of the chopper with IGBT switches working with a principle of pulse-width modulation and the H-bridge converter with IGBT switches, both working on programmed from 15 to 25 kHz frequency, and the high voltage sectioned transformer with the rectifier and additional capacity filter. The transformer is made in oil tank with silicon oil. The additional capacity filter provides low ripple and noise level in working range of output currents. A nominal output voltage of the source is 60kV, maximal voltage is 80kV. The source can operate in normal mode with series of high-voltage breakdown in output voltage. In the high-voltage breakdown the released in load and matching circuit energy is less than 15 J at maximum operating voltage 65kV. The efficiency of system is more than 80% at the nominally output power 60kW. The controller of the source is developed with DSP and PLM, which allows optimizing operations of the source. For control of the source serial CAN-interface is used. The description of the source and the test results are presented.

THPSC021	Improving of the INR DTL Tank Accelerating Voltage Stability by Means of the Anode Modulator Feedback	controls, vacuum, cathode, pick-up	366
	A. I. Kvasha RAS/INR, Moscow
	The INR DTL RF system consists of five RF channels with output pulse RF power from 1 to 2.5 MW. In turn, in every channel there are four RF vacuum tube amplifiers and two anode modulators. The output RF power amplifier anode modulator with hard discharger (vacuum tube GMI-44A) is used as executive device of accelerating voltage control system. The pulse transformer data at the GMI-44A input and time delay in the feedback of the control system don't allow ensuring the required accelerating voltage stabilization. Improving in a few times of accelerating field stabilization can be achieved by means of anode modulator feedback. Results of a numerical simulation of both feedbacks using MicroCap 8 are presented.

FRCHB03	Status of ILU-14 Electron Accelerator	electron, coupling, cathode, focusing	411
	V. S. Podobaev, V. V. Bezuglov, A. A. Bryazgin, K. N. Chernov, V. G. Cheskidov, B. L. Faktorovich, V. A. Gorbunov, I. V. Gornakov, A. V. Ivanov, E. N. Kokin, M. V. Korobeynikov, A. N. Lukin, I. Makarov, N. V. Matyash, S. A. Maximov, G. N. Ostreiko, A. D. Panfilov, V. M. Radchenko, N. D. Romashko, G. V. Serdobintsev, A. V. Sidorov, V. V. Tarnetsky, M. A. Tiunov, V. O. Tkachenko BINP SB RAS, Novosibirsk
	A new high power (up to 100 kW) industrial linear electron accelerator ILU-14 for energy of 7.5–10 MeV is under construction at Budker INP. The accelerator operates at 176 MHz with total efficiency of 26 %, its modular structure allows the electron energy and beam current to be varied within certain limits by changing the modular arrangement. The 5 MeV prototype of the accelerator was created and successfully tested in 2009. The designed average beam current of 600 mA with pulsed power of 2.5 MW and accelerating structure electron efficiency of 68 % were obtained during experiments. Applying an additional RF voltage to the electron gun cathode-grid gap allowed a beam current passing of 96 % with minor beam energy spread. The paper presents results of the numerical and experimental study of the accelerator systems together with the latest tests on the accelerator prototype.
	Slides