klystron

Paper	Title	Other Keywords	Page
TOAA03	Status of the X-Ray FEL Control System at SPring-8	controls, undulator, electron, linac	50
	T. Hirono, N. Hosoda, M. Ishii, T. Masuda, T. Matsushita, T. Ohata, M. T. Takeuchi, R. Tanaka, A. Yamashita JASRI/SPring-8, Hyogo-ken M. K. Kitamura, H. Maesaka, Y. Otake, K. Shirasawa RIKEN Spring-8 Harima, Hyogo T. Fukui RIKEN, Hyogo
	The X-ray FEL project at SPring-8 aims to build an X-ray lasing facility, which will generate brilliant coherent X-ray beams with wavelength of below 0.1nm. A combination of short-period in-vacuum undulators and an 8GeV high-gradient C-band linear accelerator makes the machine compact enough to fit into the SPring-8 1km-long beamline space. The machine commissioning will be started by March 2011. We designed the control system for the new machine based on the present SCSS test accelerator, which employs the MADOCA framework. The control system is based on the so-called “standard model” and composed of Linux-based operator consoles, database servers, Gigabit Ethernet, VMEbus system, and so on. The control system, also, has a synchronized data-taking scheme to achieve beam-based optics tuning. Most of the device control part is installed in water-cooled 19in. racks together with RF devices for temperature control, which guarantees stable RF phase control. This paper gives an overview of the project and describes the design of the control system. In addition, we briefly report the status of the SCSS test accelerator operated as a VUV-FEL user facility.
	Slides
WPPA33	Console System Using Thin Client for the J-PARC Accelerator	linac, controls, monitoring, target	383
	T. Iitsuka, S. Motohashi, M. Takagi, S. Y. Yoshida Kanto Information Service (KIS), Accelerator Group, Ibaraki N. Kamikubota, T. Katoh, H. Nakagawa, J.-I. Odagiri, N. Yamamoto KEK, Ibaraki
	An accelerator console system, based on a commercial thin client, has been developed for J-PARC accelerator operation and software development. Using thin client terminals, we expect a higher reliability and longer life-cycle due to more robust hardware (i.e., diskless and fanless configuration) than standard PCs. All of the console terminals share a common development/operation environment. We introduced LDAP (Lightweight Directory Access Protocol) for user authentication and NFS (Network File System) to provide users with standard tools and environment (EPICS tools, Java SDK, and so on) with standard directory structures. We have used the console system for beam commissioning and software development in the J-PARC. This paper describes early experiences with them.
RPPA02	Linac RF Feed-forward Development at TLS	controls, linac, electron, beam-loading	523
	K. T. Hsu, J.-Y. Hwang, D. Lee, K.-K. Lin, C. Y. Wu, K. H. Hu NSRRC, Hsinchu
	Performance of an electron linear accelerator is very important for synchrotron light source operation. Its performance in amplitude and phase of the RF field will decide the quality of extract beam. The RF feed-forward control is helpful to fixed amplitude and phase constant and keeps on stable beam extract. Design consideration and details of the implementation will be summary in this report.
RPPA13	The Electrical Power Project at SNS	SNS, controls, instrumentation, diagnostics	544
	M. P. Martinez, J. D. Purcell, E. Danilova ORNL, Oak Ridge, Tennessee
	The Electrical Power Project consists of recording data on all power-distribution devices necessary to SNS operations and how they are connected, assigning a valid name to each device and describing it, along with loading this information and the relationships into the SNS Oracle database. Interactive web-based applications allow users to display and easily update power-related data. In the case of planned electrical outages, a complete list of affected devices (including beam-line devices) will be available to controls, diagnostics, and other groups in advance. The power-tree information can be used to help diagnose electrical problems of any specific device. Fast access to device characteristics and relations from any web browser will help technical personnel quickly identify hazards and prevent electrical accidents, thereby ensuring SNS electrical safety. The project was completed by a special task team containing individuals from different groups. The paper covers the project history, QA issues, technology used, and current status.
FOAA02	Timing and LLRF System of Japanese XFEL to Realize Femto-Second Stability	acceleration, controls, laser, linac	706
	T. Fukui, N. Hosoda, H. Maesaka, T. Ohshima, T. Shintake RIKEN, Hyogo K. Imai, M. Kourogi OPtical Comb, Inc., Yokohama M. K. Kitamura, K. Tamasaku, Y. Otake RIKEN Spring-8 Harima, Hyogo M. Musya University of electro-communications, Tokyo T. Ohata JASRI/SPring-8, Hyogo-ken
	At SPring-8, the construction of a 5712-MHz linac and undulators as a light source for XFEL is in progress. There are two parts of the linac in accordance with requirements of phase accuracy to realize a stable SASE generation. One is a crest acceleration part using a sinusoidal wave. The other is an off-crest part that corresponds to a bunch compressor giving an energy chirp to a beam bunch. To generate the stable SASE, the beam energy stability of 10-4 is required. To obtain this stability, the accuracy of sub-picoseconds is required in the crest part, and several ten femto-seconds are necessary in the off-crest part. The requirement in the crest part was achieved by rf control instruments based on an electronic circuit in the SCSS prototype accelerator. However, realizing the several ten femto-seconds accuracy is almost impossible by the present electronic circuit technology. Therefore, for overcoming this fact, we employed laser technology. In this paper, we describe a system based on IQ control technology to obtain sub-picoseconds accuracy and an optical signal distribution system using an optical comb generator that could realize several ten femto-seconds accuracy.
	Slides
FOAB02	Digital Phase Control System for SSRF Linac	controls, linac, background, cathode	717
	D. K. Liu, L. Y. Yu, C. X. Yin SINAP, Shanghai
	SSRF 150MeV linac includes two klystrons and two solid power amplifers, which drive two klystrons, respectively. The accelerating section is constant gradient accelerating structure, and its working frequency is 2998MHz, six times the storage ring RF frequency. In order to reach the requirement for the RF phase stability (±1 degree), the full digital phase control system, which includes RF front-end, AD, DA, and FPGA, is designed. FPGA, the key for phase control system, contains digital I/Q demoulator (phase detector), digital I/Q modulator (phase shifter), and control algorithms. Klystron forward signal is down converted to IF (12.5MHz), which is detected by ADC with 50MHz clock. Digital I/Q is generated by ADC sampling data and then sent to control algorithms in FPGA. After processed by control algorithms, digital I/Q is converted to IF by DAC (50MHz). IF signal from DAC output is up converted to RF and sent to solid RF power amplifer. With the aid of FPGA, the whole period of closed-loop is about 80ns, and delay of closed-loop is less than 600ns. The test results of digital phase control system are presented in this paper.
	Slides