| Paper |
Title |
Page |
| TUPMA067 |
New Timing System for the L-band Linear Accelerator at Osaka University
|
208 |
| |
- S. Kashiwagi, G. Isoyama, R. Kato, S. Suemine
ISIR, Osaka
- T. Asaka, Y. Kawashima
JASRI/SPring-8, Hyogo-ken
|
|
| |
A highly precise and flexible timing system has been developed for the L-band linac at ISIR, Osaka University. It provides four RF signals and several timing signals for operation of the linac and for experiments with the linac. In order to realize long-term stability of the timing system and hence operation of the linac, a rubidium atomic clock producing a 10 MHz RF signal with the fractional stability of 10-15 is used as a time base for a synthesizer used as a master oscillator for generating the acceleration frequency of 1.3 GHz. The 1.3 GHz signal from the master oscillator is directly counted to produce the four RF signals and the clock signal of the timing system at 27 MHz. The master timing signals for linac operation is taken from the AC line frequency and it is synchronized with the 27MHz clock signal precisely. To make an arbitrary delayed timing signal, a standard digital delay generator is used to make a gate signal for a GaAs RF switch, with which one of the 27MHz clock pulses is sliced out to generate the delay timing signal. Any timing signal can be made in an interval of 37 ns and the timing jitter of the delayed signal is achieved to be as short as 2 ps.
|
|
| TUPMA068 |
Performance of the Renewed L-band Linac and Recent Progress of Development of FEL and SASE at Osaka University
|
211 |
| |
- G. Isoyama, T. Igo, S. Kashiwagi, R. Kato, Y. Kon, S. Suemine, T. Yamamoto
ISIR, Osaka
|
|
| |
The 40 MeV, L-band electron linac at the Institute of Scientific and Industrial Research, Osaka University is used for various studies on advanced beam sciences. The linac was constructed in 1975-1978 and largely remodeled in 2002-2004 for higher operational stability and reproducibility. We have evaluated performance of the renewed linac. The beam intensity is measured for longer than an hour at the exit of the linac operated in the transient mode for pulse radiolysis experiments in the nanosecond region. The intensity fluctuation is 0.27 %, which is one tenth of the value before remodeling. We are conducting development of an FEL and basic study of SASE in the far-infrared region with the linac. The experiment was suspended and resumed again after the remodeling. We have developed a strong focus wiggler for FEL and SASE based on the edge-focusing scheme, which can make the current density of the electron beam and hence the gain of FEL higher. The renewed linac can provide a long pulse electron beam up to 8 us for FEL and we are now commissioning the linac in this operation mode. We will report the performance of the renewed linac and recent development of FEL and SASE.
|
|
| WEPMA073 |
Control System based on PCs and PLCs for the L-band Linac at Osaka University
|
425 |
| |
- R. Kato, G. Isoyama, S. Kashiwagi, S. Suemine, T. Yamamoto
ISIR, Osaka
|
|
| |
The L-band electron linac at the Institute of Scientific and Industrial Research (ISIR), Osaka University, has been remodeled for higher stability and reproducibility of operation. A computer control system has been newly introduced for the linac not only to realize precise reproducibility of operation but also to make routine operation possible by even an unskilled operator. The new control system is based on personal computers (PCs) and programmable logic controllers (PLCs). The PCs and the PLCs are connected with networks using two different communication protocols. As the network connecting the PLCs, we have chosen FL-net, which is an open PLC network for factory automation. On the other hand, the PCs communicate each other with Ethernet. In order to transfer control information between these two networks with different protocols, one of the PCs is equipped with both FL-net and Ethernet and works as a gateway server. The PC converts data in the common memory in FL-net to the form accessible to the other PCs and vice versa. In this paper, we present details of the control system and operational experiences.
|
|