- Email: [email protected]
Present status of the Siam Photon Laboratory
Nuclear Instruments and Methods in Physics Research A 467–468 (2001) 51–54
Present status of the Siam Photon Laboratory Weerapong Pairsuwana, Prayoon Songsiriritthigula, Masumi Sugawaraa, Goro Isoyamaa,b, Takehiko Ishiia,* a
National Synchrotron Research Center, SUT, 111 University Avenue, P.O. Box 93, Nakhon Ratchasima Suranaree 30000, Thailand b Institute of Industrial Science, Osaka University, 8-1 Mihogaoka, Ibaraki-shi, Osaka 567-0047, Japan
Abstract The Siam Photon Project promoted at the Siam Photon Laboratory is progressing slowly but steadily. The construction of the laboratory building was completed and the installation of the accelerator complex, that is the modified SORTEC machines from Tsukuba, is now under way. The first stage of the synchrotron assembly has been completed recently. The installation of the injector linac is about to be started. The construction of the additional magnet system, the new machine control system and the new vacuum chambers have been completed. The construction of the first beam line with photoemission experimental stations as well as that for the electron beam monitor will start soon. The design work for an undulator will also start soon. Some problems found in the case of the utilization of a second hand system are described. # 2001 Elsevier Science B.V. All rights reserved. PACS: 07.85.Qe; 29.20.Oh Keywords: Synchrotron radiation facility; Siam photon project NSRC
1. Introduction The National Synchrotron Research Center (NSRC) was established in May 1996, by the Ministry of Science, Technology and Environment of Thailand for promoting the Siam Photon Project, the national synchrotron radiation research project of Thailand. The Siam Photon Laboratory belongs to NSRC. Some details of the Siam Photon Laboratory were reported in the SRI’97 Conference held in Himeji [1]. The essence of the Siam Photon Project is summarized as follows: (1) An accelerator complex consisting of a *Corresponding author. Tel.: +66-44-22-4763; fax: +66-4421-6311. E-mail address: [email protected] (T. Ishii).
40 MeV injector linac, a 1.0 GeV booster synchrotron and a 1.0 GeV storage ring for a light source is constructed. (2) Beam lines and experimental stations associated with the light source are built. More detailed descriptions of the project have been presented elsewhere [2,3]. SORTEC Laboratory in Tsukuba originally owned the accelerator complex. Whole accelerators were dismantled and the components were sent to the Siam Photon Laboratory in December 1996. Since the SORTEC Storage Ring transferred to the Siam Photon Laboratory was optimized to the microlithography studies and not suitable for other contemporary scientific research, NSRC decided to reform the storage ring so that the natural emittance of the electron beam is reduced and long straight sections for insertion devices are
0168-9002/01/$ - see front matter # 2001 Elsevier Science B.V. All rights reserved. PII: S 0 1 6 8 - 9 0 0 2 ( 0 1 ) 0 0 2 2 0 - 0
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W. Pairsuwan et al. / Nuclear Instruments and Methods in Physics Research A 467–468 (2001) 51–54
installed. Owing to this reformation, the circumference of the storage ring is almost doubled and for some quadruple, sextuple and steering magnets are added. The vacuum chambers had to be renewed. The machine control system used in the SORTEC Machine system was abandoned. When the Siam Photon Project was first planned, we did not consider that a 1.0 GeV storage ring could generate hard X-rays. Thus, the major scientific research subjects planned in the earlier stage were those for the VUV–SX spectroscopy including photoemission. However, the insertion device technology has advanced rapidly and it is now possible to obtain hard X-rays with photon energies high enough to enable ordinary X-ray diffraction experiments with a 1.0 GeV storage ring if a superconducting magnet wiggler is used. Therefore, the installation of superconducting magnet wigglers in the storage ring and construction of X-ray beam lines have become important objectives of the Siam Photon Project. In what follows, we describe the progress of the project made recently. Since we are still in
the stage of light source construction, most of the reports presented here are on the accelerator complex part. The layout of the accelerator complex is schematically shown in Fig. 1.
2. Recent developments In the past three years, the project has progressed and various kinds of construction and design work have been completed. They are as follows: (1) The main building of the Siam Photon Laboratory, where the accelerator complex, power supplies, cooling water supplies, the machine control system and experimental hall are located. (2) The new vacuum chambers and the associated evacuation system. (3) The magnet systems to be added to the reformed storage ring. (4) The new machine control system.
Fig. 1. Schematic illustration of the layout of the accelerator complex. The injector linac, the synchrotron and two beam transport lines, are installed underground. In the figure, the underground level and the ground level are illustrated as if they are on the same level.
W. Pairsuwan et al. / Nuclear Instruments and Methods in Physics Research A 467–468 (2001) 51–54
(5) The measurements of the characteristics of the RF cavity of the storage ring. (6) The simulation of the radiation intensity distribution around the Siam Photon Laboratory including that of the sky shine. (7) The design work of the radiation monitoring posts. (8) The design work of the first two beam lines, one for the electron beam monitoring and the other for the photoemission experiments.
3. Machine control system Among the progress mentioned above, some more details of the machine control system are worth describing. The basic concept of the control system was reported elsewhere [4]. 3.1. Hardware 3.1.1. Computers The hardware of the control system comprises personal computers (PC’s) and programmable device controllers (PLC’s). They are connected to each other through LAN. In the machine control room, two PCs, one for the control server (CNT-SRV) and other for the data acquisition server (ACQ-SRV), are installed along with three PCs used as operational terminal equipment. 3.1.2. Device control stations Pairs of PLC and the interface of the individual instrument, called the device control stations (DCS’s) are installed in four different rooms in the building. They are in the synchrotron room (Linac-LBT DCS), the electric substation room (DCS for synchrotron power supplies), the storage ring room (storage ring DCS) and the machine control room (control DCS and global interlock DCS). 3.1.3. Local area network (LAN) LAN connecting the computers and DCSs is made with the ordinary Ethernet. In the control room a hub is located. PCs and PLC are connected
53
to this hub with optical fibers installed between different rooms and with 100 Base-T cable installed in side a room 3.2. Function and operation The six PLCs observe the states of individual instruments and control them independent of each other. The language for PLC’s is the ladder for the programmable logic control. The control and the state observation are carried out with an interval of 10 ms. The Operation System used in the two server PCs and the three PCs as terminal equipment is Windows NT 4.0. CNT-SRV is directly connected to the circuit for the pattern memory and the timing control for the synchrotron and controls them. It also controls the automatic operation such as the start and stop of the accelerator system. ACQ-SRV observes the conditions of individual component instruments through PLC and memorizes as the data base. It has a function of the web server, which enable the state observation of the accelerator complex from the outside of the system. Two different types of graphical user interface (GUI) are used for the control of individual component instruments. One shows realistic pictures like one for the locations of the instruments and the other shows the data like tables. 3.3. Distinctive aspects The distinctive aspects of the control system used here are summarized as follows: (1) It is a dispersed processing system. (2) Only commonly used units like PC and PLC are employed. (3) The system can be reformed and/or expanded easily in the future. (4) The use of PLC does not cause operation errors and the system is reliable.
4. Problems found in machine reassemble When a used facility is transferred to another laboratory for further use, the components of the
54
W. Pairsuwan et al. / Nuclear Instruments and Methods in Physics Research A 467–468 (2001) 51–54
whole machine and beam line systems are inevitably stored in a warehouse for a certain period. In the case of the Siam Photon Project, the components of the SORTEC accelerator complex have been stored in a warehouse for more than three years. Meanwhile, the linac system was reassembled and kept under good conditions for two years, so that the deterioration would not occur. In the power supplies of the synchrotron a lot of semiconductor devices are used. They are found to be operational even after an unused period of 3.5 yr. Instead, some of the mechanically movable parts, such as fans to ventilate a power supply are found degraded. The cause is that the lubricant has been damaged chemically. Other defects found were not serious; for instance bulbs in indicator lamps were found dead. Serious defects in the infrastructure are found in the water supply system including the related bad workmanship. Although they may be peculiar to the Siam Photon Laboratory, this could not be foreseen. For instance, the indications of pressure gauges and thermometers are found to be incorrect.
5. Beam line The beam line design was made by dividing the whole optical system into three parts. One is the front-end part, where elements such as masks, a
beam shutter and fast closing valves are installed. The second is the main optical system consisting of various focusing mirrors and a monochromator. Monochromatized light is focused on a sample in a small spot form. A varied line-spacing grating monochromator is employed. A resolving power of about 5000 is obtained over a photon energy range of 20–300 eV. The third part is the experimental stations for photoemission. The details of the beam line are presented elsewhere [5]. In addition to the photoemission experiment beam line, a beam line for the electron-beam monitor shall be built.
References [1] W. Pairsuwan, T. Ishii, J. Synchotron Rad. 5 (1998) 1173. [2] W. Pairsuwan, T. Ishii, Abstracts of III Asian Forum on Synch. Rad. held at Kamigori-Hyogo, 1997, Japan Soc. Synch. Rad. Res, Tokyo, 1997, p. 149 [3] W. Pairsuwan, T. Ishii, Proceedings of the I. Asian Particle Accelerator Conference, APAC 98, March. 1998, High Energy Accelerator Organization, 1998, p. 36 [4] W. Pairsuwan, T. Ishii, G. Isoyama, T. Yamakawa, Y. Hirata, N. Tsuzuki, T. Takeda, Proceedings of II. International Workshop on Personal Computers and Particle Accelerator Controls, held at Tsukuba, Jan. 1999, KEK Proceeding 98-14, FR 5. [5] P. Songsiriritthigul, P. Sombunchoo, B.N. Raja Sekhar, W. Pairsuwan, T. Ishii, A. Kakizaki, Nucl. Instr. and Meth. A 467–468 (2001), these proceedings.
Present status of the Siam Photon Laboratory Weerapong Pairsuwana, Prayoon Songsiriritthigula, Masumi Sugawaraa, Goro Isoyamaa,b, Takehiko Ishiia,* a
National Synchrotron Research Center, SUT, 111 University Avenue, P.O. Box 93, Nakhon Ratchasima Suranaree 30000, Thailand b Institute of Industrial Science, Osaka University, 8-1 Mihogaoka, Ibaraki-shi, Osaka 567-0047, Japan
Abstract The Siam Photon Project promoted at the Siam Photon Laboratory is progressing slowly but steadily. The construction of the laboratory building was completed and the installation of the accelerator complex, that is the modified SORTEC machines from Tsukuba, is now under way. The first stage of the synchrotron assembly has been completed recently. The installation of the injector linac is about to be started. The construction of the additional magnet system, the new machine control system and the new vacuum chambers have been completed. The construction of the first beam line with photoemission experimental stations as well as that for the electron beam monitor will start soon. The design work for an undulator will also start soon. Some problems found in the case of the utilization of a second hand system are described. # 2001 Elsevier Science B.V. All rights reserved. PACS: 07.85.Qe; 29.20.Oh Keywords: Synchrotron radiation facility; Siam photon project NSRC
1. Introduction The National Synchrotron Research Center (NSRC) was established in May 1996, by the Ministry of Science, Technology and Environment of Thailand for promoting the Siam Photon Project, the national synchrotron radiation research project of Thailand. The Siam Photon Laboratory belongs to NSRC. Some details of the Siam Photon Laboratory were reported in the SRI’97 Conference held in Himeji [1]. The essence of the Siam Photon Project is summarized as follows: (1) An accelerator complex consisting of a *Corresponding author. Tel.: +66-44-22-4763; fax: +66-4421-6311. E-mail address: [email protected] (T. Ishii).
40 MeV injector linac, a 1.0 GeV booster synchrotron and a 1.0 GeV storage ring for a light source is constructed. (2) Beam lines and experimental stations associated with the light source are built. More detailed descriptions of the project have been presented elsewhere [2,3]. SORTEC Laboratory in Tsukuba originally owned the accelerator complex. Whole accelerators were dismantled and the components were sent to the Siam Photon Laboratory in December 1996. Since the SORTEC Storage Ring transferred to the Siam Photon Laboratory was optimized to the microlithography studies and not suitable for other contemporary scientific research, NSRC decided to reform the storage ring so that the natural emittance of the electron beam is reduced and long straight sections for insertion devices are
0168-9002/01/$ - see front matter # 2001 Elsevier Science B.V. All rights reserved. PII: S 0 1 6 8 - 9 0 0 2 ( 0 1 ) 0 0 2 2 0 - 0
52
W. Pairsuwan et al. / Nuclear Instruments and Methods in Physics Research A 467–468 (2001) 51–54
installed. Owing to this reformation, the circumference of the storage ring is almost doubled and for some quadruple, sextuple and steering magnets are added. The vacuum chambers had to be renewed. The machine control system used in the SORTEC Machine system was abandoned. When the Siam Photon Project was first planned, we did not consider that a 1.0 GeV storage ring could generate hard X-rays. Thus, the major scientific research subjects planned in the earlier stage were those for the VUV–SX spectroscopy including photoemission. However, the insertion device technology has advanced rapidly and it is now possible to obtain hard X-rays with photon energies high enough to enable ordinary X-ray diffraction experiments with a 1.0 GeV storage ring if a superconducting magnet wiggler is used. Therefore, the installation of superconducting magnet wigglers in the storage ring and construction of X-ray beam lines have become important objectives of the Siam Photon Project. In what follows, we describe the progress of the project made recently. Since we are still in
the stage of light source construction, most of the reports presented here are on the accelerator complex part. The layout of the accelerator complex is schematically shown in Fig. 1.
2. Recent developments In the past three years, the project has progressed and various kinds of construction and design work have been completed. They are as follows: (1) The main building of the Siam Photon Laboratory, where the accelerator complex, power supplies, cooling water supplies, the machine control system and experimental hall are located. (2) The new vacuum chambers and the associated evacuation system. (3) The magnet systems to be added to the reformed storage ring. (4) The new machine control system.
Fig. 1. Schematic illustration of the layout of the accelerator complex. The injector linac, the synchrotron and two beam transport lines, are installed underground. In the figure, the underground level and the ground level are illustrated as if they are on the same level.
W. Pairsuwan et al. / Nuclear Instruments and Methods in Physics Research A 467–468 (2001) 51–54
(5) The measurements of the characteristics of the RF cavity of the storage ring. (6) The simulation of the radiation intensity distribution around the Siam Photon Laboratory including that of the sky shine. (7) The design work of the radiation monitoring posts. (8) The design work of the first two beam lines, one for the electron beam monitoring and the other for the photoemission experiments.
3. Machine control system Among the progress mentioned above, some more details of the machine control system are worth describing. The basic concept of the control system was reported elsewhere [4]. 3.1. Hardware 3.1.1. Computers The hardware of the control system comprises personal computers (PC’s) and programmable device controllers (PLC’s). They are connected to each other through LAN. In the machine control room, two PCs, one for the control server (CNT-SRV) and other for the data acquisition server (ACQ-SRV), are installed along with three PCs used as operational terminal equipment. 3.1.2. Device control stations Pairs of PLC and the interface of the individual instrument, called the device control stations (DCS’s) are installed in four different rooms in the building. They are in the synchrotron room (Linac-LBT DCS), the electric substation room (DCS for synchrotron power supplies), the storage ring room (storage ring DCS) and the machine control room (control DCS and global interlock DCS). 3.1.3. Local area network (LAN) LAN connecting the computers and DCSs is made with the ordinary Ethernet. In the control room a hub is located. PCs and PLC are connected
53
to this hub with optical fibers installed between different rooms and with 100 Base-T cable installed in side a room 3.2. Function and operation The six PLCs observe the states of individual instruments and control them independent of each other. The language for PLC’s is the ladder for the programmable logic control. The control and the state observation are carried out with an interval of 10 ms. The Operation System used in the two server PCs and the three PCs as terminal equipment is Windows NT 4.0. CNT-SRV is directly connected to the circuit for the pattern memory and the timing control for the synchrotron and controls them. It also controls the automatic operation such as the start and stop of the accelerator system. ACQ-SRV observes the conditions of individual component instruments through PLC and memorizes as the data base. It has a function of the web server, which enable the state observation of the accelerator complex from the outside of the system. Two different types of graphical user interface (GUI) are used for the control of individual component instruments. One shows realistic pictures like one for the locations of the instruments and the other shows the data like tables. 3.3. Distinctive aspects The distinctive aspects of the control system used here are summarized as follows: (1) It is a dispersed processing system. (2) Only commonly used units like PC and PLC are employed. (3) The system can be reformed and/or expanded easily in the future. (4) The use of PLC does not cause operation errors and the system is reliable.
4. Problems found in machine reassemble When a used facility is transferred to another laboratory for further use, the components of the
54
W. Pairsuwan et al. / Nuclear Instruments and Methods in Physics Research A 467–468 (2001) 51–54
whole machine and beam line systems are inevitably stored in a warehouse for a certain period. In the case of the Siam Photon Project, the components of the SORTEC accelerator complex have been stored in a warehouse for more than three years. Meanwhile, the linac system was reassembled and kept under good conditions for two years, so that the deterioration would not occur. In the power supplies of the synchrotron a lot of semiconductor devices are used. They are found to be operational even after an unused period of 3.5 yr. Instead, some of the mechanically movable parts, such as fans to ventilate a power supply are found degraded. The cause is that the lubricant has been damaged chemically. Other defects found were not serious; for instance bulbs in indicator lamps were found dead. Serious defects in the infrastructure are found in the water supply system including the related bad workmanship. Although they may be peculiar to the Siam Photon Laboratory, this could not be foreseen. For instance, the indications of pressure gauges and thermometers are found to be incorrect.
5. Beam line The beam line design was made by dividing the whole optical system into three parts. One is the front-end part, where elements such as masks, a
beam shutter and fast closing valves are installed. The second is the main optical system consisting of various focusing mirrors and a monochromator. Monochromatized light is focused on a sample in a small spot form. A varied line-spacing grating monochromator is employed. A resolving power of about 5000 is obtained over a photon energy range of 20–300 eV. The third part is the experimental stations for photoemission. The details of the beam line are presented elsewhere [5]. In addition to the photoemission experiment beam line, a beam line for the electron-beam monitor shall be built.
References [1] W. Pairsuwan, T. Ishii, J. Synchotron Rad. 5 (1998) 1173. [2] W. Pairsuwan, T. Ishii, Abstracts of III Asian Forum on Synch. Rad. held at Kamigori-Hyogo, 1997, Japan Soc. Synch. Rad. Res, Tokyo, 1997, p. 149 [3] W. Pairsuwan, T. Ishii, Proceedings of the I. Asian Particle Accelerator Conference, APAC 98, March. 1998, High Energy Accelerator Organization, 1998, p. 36 [4] W. Pairsuwan, T. Ishii, G. Isoyama, T. Yamakawa, Y. Hirata, N. Tsuzuki, T. Takeda, Proceedings of II. International Workshop on Personal Computers and Particle Accelerator Controls, held at Tsukuba, Jan. 1999, KEK Proceeding 98-14, FR 5. [5] P. Songsiriritthigul, P. Sombunchoo, B.N. Raja Sekhar, W. Pairsuwan, T. Ishii, A. Kakizaki, Nucl. Instr. and Meth. A 467–468 (2001), these proceedings.