CYCLOTRONS 2010 - List of Keywords (monitoring)

Paper	Title	Other Keywords	Page
MOPCP008	Control System of Cryogenic Plant for Superconducting Cyclotron at VECC	controls, cyclotron, cryogenics, superconducting-magnet	57
	U. Panda, T. Bhattacharjee, R. Dey, A. Mandal, S. Pal DAE/VECC, Calcutta, India
	Cryogenic Plant of Variable Energy Cyclotron Centre consists of two Helium refrigerators (250 W and 415 W @ 4.5K), valve box with sub-cooler and associated sub systems like pure gas storage, helium purifier and impure gas recovery etc. The system also consists of 3.1K liters of liquid Nitrogen (LN2) storage and delivery system. The plant is designed to cater the cryogenic requirements of the Superconducting Cyclotron. The control system is fully automated and does not require any human intervention once it is started. EPICS architecture has been adopted to design the SCADA module. The EPICS Input Output Controller (IOC) communicates with four Programmable Logic Controllers (PLCs) over Ethernet based control LAN to control/monitor 618 numbers of field inputs/ outputs. The plant is running very reliably round the clock, however, the historical data trending of important parameters during plant operation has been integrated to the system for plant maintenance and easy diagnosis. The 400 kVA UPS with 10 minutes back up time have been installed to keep the cryogenic system running with one 160 kW cycle compressor during utility power interruptions.

MOPCP009	Development of Power Supplies for 3-Ф, 240 kW RF System with Crowbar Protection for Superconducting Cyclotron at VECC	power-supply, controls, cyclotron, coupling	60
	S.K. Thakur, R.K. Bhandari, A. De, Y. Kumar, J.S.P. Prasad, S. Saha, S.S. Som, T.P. Tiwari DAE/VECC, Calcutta, India
	RF system of K-500 super conducting cyclotron at VECC is a complex three phase system operating in the frequency range of 9 MHz to 27 MHz with maximum acceleration potential of around 100 kV feeding to each of three Dee cavities placed in median plane of cyclotron 120° apart through coupling capacitors. Each phase consists of chain of amplifiers and resonator operating in synchronization and at final stage of each phase, a high power water cooled Tetrode Tube (Eimac 4CW 150,000 E) as an RF high power amplifier each capable of delivering 80 kW of RF power. Individual power supplies for biasing Anode (20 kV, 22 Amp), Filament (16 V, 225 Amp), Screen (1600 V, 1 Amp) and grid (-500 V, 0.1 Amp) each for all three high power Tetrode Tubes are designed, developed and commissioned indigenously in VECC Cyclotron building and have been in operation from last few months successfully. Anode supply is common to all three tubes, rated at 20 kV, 22 Amp, 450 kW along with fast acting crowbar protection using Ignitron. This paper describes about the technical challenges in the development of the power supplies and special features of protection systems.

MOPCP068	Stable Operation of RF Systems for RIBF	controls, cyclotron, pick-up, heavy-ion	186
	K. Suda, M. Fujimaki, N. Fukunishi, M. Hemmi, O. Kamigaito, M. Kase, R. Koyama, K. Kumagai, N. Sakamoto, T. Watanabe, K. Yamada RIKEN Nishina Center, Wako, Japan
	At RIKEN RI-Beam Factory (RIBF), heavy ion beams are accelerated up to 345 MeV/u by using the RIKEN heavy ion linac (RILAC) and four ring cyclotrons. In order to provide high intensity beams up to 1puA, all the RF systems must be stable enough for a long term (a few weeks), within ±0.1% in voltages and ±0.1 degrees in phases. For a stable operation of RIBF, we have started to monitor for the RF voltages and phases for all the RF systems, and beam intensity and phases using lock-in amplifiers. We have investigated a degree of stability of the RF systems. Then, we have performed several improvements. The Automatic Gain Control units for RILAC were replaced for a better stability. It was found that the stability of RF systems was considerably affected by the fluctuation of reference signals. The fluctuation was mainly caused by the temperature dependence of power dividers used for a reference signal distribution. Therefore, we have changed the distribution method. The reference signal is first amplified to 40 dBm and divided by directional couplers, and they are delivered to low level circuits. The present degree of stability of the RF systems will be presented.

MOPCP094	Consistency in Measurement of Beam Phase and Beam Intensity Using Lock-in Amplifier and Oscilloscope Systems	cyclotron, acceleration, beam-transport, rfq	245
	R. Koyama, M. Fujimaki, N. Fukunishi, A. Goto, M. Hemmi, O. Kamigaito, M. Kase, N. Sakamoto, K. Suda, T. Watanabe, K. Yamada RIKEN Nishina Center, Wako, Japan
	The RIKEN RI beam factory (RIBF) consists of four ring cyclotrons (RRC, fRC, IRC, and SRC) and two injectors (RILAC and AVF) which are all connected in cascade. RILAC, AVF, and RRC began operation in the 1980s, and fRC, IRC, and SRC were installed in 2006. Phase probes (PPs) are installed in all cyclotrons and beam transport lines of RIBF, and the beam-bunch signals that are detected nondestructively by these PPs are used for tuning of isochronous magnetic field of cyclotrons and for monitoring the beam phase and beam intensity. We mainly use a newly developed system that incorporates a lock-in amplifier (LIA; SR844, SRS) for those tuning and monitoring; however, in AVF and RRC, a conventional measurement method using an oscilloscope system (OSC; DSO6052A, Agilent) is used. In this study, we investigated the consistency in the measurements carried out using LIA and OSC systems by Fourier analyzing the observed data. Additionally, we investigated the resolution and measurement uncertainty of LIA and OSC.

WEM2CCO05	Beam Diagnostics for RIBF in RIKEN	cyclotron, ion, pick-up, emittance	351
	T. Watanabe, M. Fujimaki, N. Fukunishi, O. Kamigaito, M. Kase, M. Komiyama, R. Koyama, H. Watanabe RIKEN Nishina Center, Wako, Japan
	In the present work, many varieties of beam diagnostics have been played a tremendous role for the RIBF (RI Beam Factory) in RIKEN. During beam user's experiments, it is essential to keep the beam transmission efficiency as high as possible, because the production of RI beams requires an intense primary beam, and the activation of the beam transport chambers induced by beam loss should be avoided. This presentation will include the overview of the Faraday cups, the transverse beam profile monitors, radial probes and phase probes to tune the accelerators and the beam transport line. To realize the stable operation of the accelerator complex, the nondestructive monitoring system of RF fields and beam-phase by using lock-in amplifies are used. Plastic scintillation monitors have been fabricated to evaluate the energy and longitudinal profiles of heavy-ion beams. Furthermore, a highly sensitive beam current (position) monitor with a high Tc (Critical Temperature) SQUID (Superconducting QUantum Interference Device) monitor, has been developed. We will report the present status of the facility, the details of the beam diagnostics and the results of the beam measurement.
	Slides WEM2CCO05 [6.855 MB]

Paper

Title

Other Keywords

Page

MOPCP008

Control System of Cryogenic Plant for Superconducting Cyclotron at VECC

controls, cyclotron, cryogenics, superconducting-magnet

57

U. Panda, T. Bhattacharjee, R. Dey, A. Mandal, S. Pal
DAE/VECC, Calcutta, India

Cryogenic Plant of Variable Energy Cyclotron Centre consists of two Helium refrigerators (250 W and 415 W @ 4.5K), valve box with sub-cooler and associated sub systems like pure gas storage, helium purifier and impure gas recovery etc. The system also consists of 3.1K liters of liquid Nitrogen (LN2) storage and delivery system. The plant is designed to cater the cryogenic requirements of the Superconducting Cyclotron. The control system is fully automated and does not require any human intervention once it is started. EPICS architecture has been adopted to design the SCADA module. The EPICS Input Output Controller (IOC) communicates with four Programmable Logic Controllers (PLCs) over Ethernet based control LAN to control/monitor 618 numbers of field inputs/ outputs. The plant is running very reliably round the clock, however, the historical data trending of important parameters during plant operation has been integrated to the system for plant maintenance and easy diagnosis. The 400 kVA UPS with 10 minutes back up time have been installed to keep the cryogenic system running with one 160 kW cycle compressor during utility power interruptions.

MOPCP009

Development of Power Supplies for 3-Ф, 240 kW RF System with Crowbar Protection for Superconducting Cyclotron at VECC

power-supply, controls, cyclotron, coupling

60

S.K. Thakur, R.K. Bhandari, A. De, Y. Kumar, J.S.P. Prasad, S. Saha, S.S. Som, T.P. Tiwari
DAE/VECC, Calcutta, India

RF system of K-500 super conducting cyclotron at VECC is a complex three phase system operating in the frequency range of 9 MHz to 27 MHz with maximum acceleration potential of around 100 kV feeding to each of three Dee cavities placed in median plane of cyclotron 120° apart through coupling capacitors. Each phase consists of chain of amplifiers and resonator operating in synchronization and at final stage of each phase, a high power water cooled Tetrode Tube (Eimac 4CW 150,000 E) as an RF high power amplifier each capable of delivering 80 kW of RF power. Individual power supplies for biasing Anode (20 kV, 22 Amp), Filament (16 V, 225 Amp), Screen (1600 V, 1 Amp) and grid (-500 V, 0.1 Amp) each for all three high power Tetrode Tubes are designed, developed and commissioned indigenously in VECC Cyclotron building and have been in operation from last few months successfully. Anode supply is common to all three tubes, rated at 20 kV, 22 Amp, 450 kW along with fast acting crowbar protection using Ignitron. This paper describes about the technical challenges in the development of the power supplies and special features of protection systems.

MOPCP068

Stable Operation of RF Systems for RIBF

controls, cyclotron, pick-up, heavy-ion

186

K. Suda, M. Fujimaki, N. Fukunishi, M. Hemmi, O. Kamigaito, M. Kase, R. Koyama, K. Kumagai, N. Sakamoto, T. Watanabe, K. Yamada
RIKEN Nishina Center, Wako, Japan

At RIKEN RI-Beam Factory (RIBF), heavy ion beams are accelerated up to 345 MeV/u by using the RIKEN heavy ion linac (RILAC) and four ring cyclotrons. In order to provide high intensity beams up to 1puA, all the RF systems must be stable enough for a long term (a few weeks), within ±0.1% in voltages and ±0.1 degrees in phases. For a stable operation of RIBF, we have started to monitor for the RF voltages and phases for all the RF systems, and beam intensity and phases using lock-in amplifiers. We have investigated a degree of stability of the RF systems. Then, we have performed several improvements. The Automatic Gain Control units for RILAC were replaced for a better stability. It was found that the stability of RF systems was considerably affected by the fluctuation of reference signals. The fluctuation was mainly caused by the temperature dependence of power dividers used for a reference signal distribution. Therefore, we have changed the distribution method. The reference signal is first amplified to 40 dBm and divided by directional couplers, and they are delivered to low level circuits. The present degree of stability of the RF systems will be presented.

MOPCP094

Consistency in Measurement of Beam Phase and Beam Intensity Using Lock-in Amplifier and Oscilloscope Systems

cyclotron, acceleration, beam-transport, rfq

245

R. Koyama, M. Fujimaki, N. Fukunishi, A. Goto, M. Hemmi, O. Kamigaito, M. Kase, N. Sakamoto, K. Suda, T. Watanabe, K. Yamada
RIKEN Nishina Center, Wako, Japan

The RIKEN RI beam factory (RIBF) consists of four ring cyclotrons (RRC, fRC, IRC, and SRC) and two injectors (RILAC and AVF) which are all connected in cascade. RILAC, AVF, and RRC began operation in the 1980s, and fRC, IRC, and SRC were installed in 2006. Phase probes (PPs) are installed in all cyclotrons and beam transport lines of RIBF, and the beam-bunch signals that are detected nondestructively by these PPs are used for tuning of isochronous magnetic field of cyclotrons and for monitoring the beam phase and beam intensity. We mainly use a newly developed system that incorporates a lock-in amplifier (LIA; SR844, SRS) for those tuning and monitoring; however, in AVF and RRC, a conventional measurement method using an oscilloscope system (OSC; DSO6052A, Agilent) is used. In this study, we investigated the consistency in the measurements carried out using LIA and OSC systems by Fourier analyzing the observed data. Additionally, we investigated the resolution and measurement uncertainty of LIA and OSC.

WEM2CCO05

Beam Diagnostics for RIBF in RIKEN

cyclotron, ion, pick-up, emittance

351

T. Watanabe, M. Fujimaki, N. Fukunishi, O. Kamigaito, M. Kase, M. Komiyama, R. Koyama, H. Watanabe
RIKEN Nishina Center, Wako, Japan

In the present work, many varieties of beam diagnostics have been played a tremendous role for the RIBF (RI Beam Factory) in RIKEN. During beam user's experiments, it is essential to keep the beam transmission efficiency as high as possible, because the production of RI beams requires an intense primary beam, and the activation of the beam transport chambers induced by beam loss should be avoided. This presentation will include the overview of the Faraday cups, the transverse beam profile monitors, radial probes and phase probes to tune the accelerators and the beam transport line. To realize the stable operation of the accelerator complex, the nondestructive monitoring system of RF fields and beam-phase by using lock-in amplifies are used. Plastic scintillation monitors have been fabricated to evaluate the energy and longitudinal profiles of heavy-ion beams. Furthermore, a highly sensitive beam current (position) monitor with a high Tc (Critical Temperature) SQUID (Superconducting QUantum Interference Device) monitor, has been developed. We will report the present status of the facility, the details of the beam diagnostics and the results of the beam measurement.

Slides WEM2CCO05 [6.855 MB]