- Email: [email protected]
The plasma movie database system for JT-60
Fusion Engineering and Design 82 (2007) 1008–1014
The plasma movie database system for JT-60 Michiharu Sueoka a,∗ , Yoichi Kawamata a , Kenichi Kurihara a , Akiyuki Seki b a b
Japan Atomic Energy Agency, Fusion Research and Development Directorate, 801-1 Mukoyama, Naka-shi, Ibaraki-ken 311-0193, Japan Japan Atomic Energy Agency, Information Technology Systems’ Management and Operating Office, 2-4 Shirane, Shirakata, Tokai-mura, Naka-gun, Ibaraki-ken 319-1195, Japan Received 10 August 2006; received in revised form 26 February 2007; accepted 26 February 2007 Available online 30 March 2007
Abstract The real-time plasma movie with the computer graphics (CG) of plasma shape is one of the most effective methods to know what discharge have been made in the experiment. For an easy use of the movie in the data analysis, we have developed the plasma movie database system (PMDS), which automatically records plasma movie according to the JT-60 discharge sequence, and transfers the movie files on request from the web site. The file is compressed to about 8 MB/shot small enough to be transferred within a few seconds through local area network (LAN). In this report, we describe the developed system from the technical point of view, and discuss a future plan on the basis of advancing video technology. © 2007 Elsevier B.V. All rights reserved. Keywords: JT-60; Real-time; Plasma; Shape; Movie; Database; Web site; Video technology; CG; NTSC; MPEG2/MPEG4
1. Introduction The world tokamak fusion devices have exploited advanced reactor scenarios by optimizing plasma control methods [1–3]. In their experiments, efficient evaluation is one of the key issues for fast understanding of plasma performance. As a solution, we have provided a real-time plasma movie for the large monitor TV in the JT-60 central control room since 1997. This movie is composed of three elements: a video cam∗ Corresponding author. Tel.: +81 292707423; fax: +81 292707459. E-mail address: [email protected] (M. Sueoka).
0920-3796/$ – see front matter © 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.fusengdes.2007.02.026
era picture, the plasma shape computer graphics (CG) calculated by the plasma shape reconstruction system (PSRS) [4], and a sound (audio amplified signal of magnetic probe voltage). This movie makes it possible for us to compare the video camera picture and the plasma shape CG in a single monitor view. If this movie can be easily replayed even after the discharge shot, such a visual material could provide useful information to the physicists efficiently. For this motivation, we have developed the plasma movie database system (PMDS) having the following features: (1) small data size movie with low resolution is prepared for fast transfer through LAN after the shot and (2) larger data size movie with high res-
M. Sueoka et al. / Fusion Engineering and Design 82 (2007) 1008–1014
olution is also prepared to check the performance of real-time plasma position control algorithms and shape calculation, and to check machine safety. We are considering to improve the picture quality by developing a new real-time visualization system (RVS) producing full-digital CG together with high definition television (HDTV) standard. We believe PMDS might be one of the essential elements for a tokamak power reactor.
2. Configuration of the plasma movie database system (PMDS) Hardware configuration of PMDS is illustrated in Fig. 1. The plasma video camera picture is taken by a standard video camera, equipped at the viewing port of the vacuum vessel looking at a plasma poloidal cross section. RVS for the plasma shape CG (25 ms/shape) is linked with PSRS for shape reconstruction (1 ms/shape) through the reflective memory network. This system outputs the digital picture signal (RGB) to the scanning line converter using the optical fiber cables as indicated in a dotted line in Fig. 1. The scanning line converter changes an RGB signal into lower scanning line analog-signal (NTSC: the National Television Systems Committee), and output this NTSC to the multiple views composer. The composer combines the plasma video camera picture and plasma shape CG into one view as shown in Fig. 2. This composer, available on the market, trims the halves of two different NTSC-based screens, and merges them into one view. The combined NTSC signal is displayed on the large monitor TV and is input to the plasma movie capturing system (PMCS). A raw voltage signal from a magnetic pick-up coil is also input to the sound channel via an audio amplifier. PMCS receives the timing signal according to the JT-60 discharge sequence, and controls the management tasks to handle movie files. In addition, this system executes two types of compression, MPEG2 and MPEG4, for an effective database operation. The MPEG4 movie file is transferred to the plasma movie web server, while the MPEG2 movie file is stored in the RAID (redundant array of inexpensive disks). The plasma movie web server provides a web site dealing with the selection of plasma movie specified by
1009
the JT-60 shot number. A user who wants to observe the movie may access the web site for download of a movie file. The detailed system specifications will be presented in the following sections. 3. Production of the plasma movie data The plasma movie includes the video picture, shape CG, and the sound, as mention above. Each element is quickly explained below: (1) Plasma video picture: The original signal of this picture is based on NTSC standard which is employed for analog television signal standard in Canada, Japan, South Korea, the United States, etc. The specification of this signal is 640 × 480 pixels in resolution and 30 frames per second in speed. (2) Computer graphics of plasma shape: A plasma shape is calculated in the 1 ms cycle using the shape reconstruction method (the CCS (Caushy condition surface) method [4]) by the plasma shape reconstruction system. These pictures produced by RVS show plasma shape together with time evolution of plasma current. This picture has 1000 × 1000 pixels in resolution. (3) Sound data: This sound signal provides the magnetic field fluctuations measured by a magnetic probe sensor equipped in the vacuum vessel. This sound implies various plasma states: changes in plasma rotation speed appears to be a change in the tone of sound. A stable plasma produces smooth high tone as a plasma rotates at a constant speed. On the other hand, an unstable plasma appears to be noisy low tone as a plasma rotates at an irregular speed. 4. Plasma movie capturing system (PMCS) Since the combined movie signal is captured in a computer system, the size of movie data should be discussed the first. The original (not compressed) movie data requires huge disk volume. For example, the estimate of this file size for 1 s is: 640 × 480 pixels × 3 bytes (24 bit full-color) × 30 frames = 27.5 MB. For 1 min discharge, 27.5 MB/s × 65 s = 1.8 GB in total.
1010
M. Sueoka et al. / Fusion Engineering and Design 82 (2007) 1008–1014
Fig. 1. Hardware configuration of the plasma movie database system.
Since the data amount is considerably large, the NTSC-based movie must be compressed to MPEG2based movie. The system converts NTSC to MPEG2, and records the resultant MPEG2 movie file automatically in its own disk using the movie capture board (MVR-D2200V manufactured by Canopus Co., Ltd.).
The MPEG2 movie file amount is about 50 MB/shot for 65 s discharge. RAID stores MPEG2 movie file for 250 experiment days (5000 shots) including the back-up data. Immediately after the system complete recording MPEG2 movie, it starts converting from MPEG2 to MPEG4
M. Sueoka et al. / Fusion Engineering and Design 82 (2007) 1008–1014
1011
Fig. 2. An example view of the plasma movie.
using the movie compression software (ProCorder2.0 manufactured by Canopus Co., Ltd.). The MPEG4 movie file amount is about 8 MB/shot for 65 s discharge. This conversion time requires approximately 4–5 min using Pentium4 (3.8 GHz) CPU with 1 GB core memory. When the conversion is completed, the system transfers an MPEG4 movie file to the plasma movie web server. The plasma movie web server’s disk stores an MPEG4 movie file for 1000 experiment days (20,000 shots). The difference of the specification for MPEG2 and MPEG4 is shown in the Table 1. The employed specification of MPEG2 resolution (720 × 480 pixels) is as good as the S-VHS video, and is better than NTSC (640 × 480 pixels: VGA (video graphics array)). Although higher quality MPEG2 specification corresponding to HDTV
(1920 × 1080 pixels) could be available, we adopted standard MPEG2, because the original signal is categorized in low-resolution picture. MPEG4 can be handled in many free video player software. Since an MPEG4 movie file is transferred through LAN, we chose resolution 320 × 240 pixels (Quarter VGA) which is smaller than MPEG2 not only in resolution but also in the video bit rate. The system automatically records plasma movie according to the timing signal of JT-60 discharge sequence. The time schedule is shown in Fig. 3. This system receives three timing signals. The actions to each signal are shown below: (1) When received the “1 min before discharge signal”, the action is to prepare the record.
Table 1 The specification of a recorded file Compression method
Resolution
Video bit rate (Mbps)
Audio bit rate (Kbps)
Estimate file size (65 s) (MB)
MPEG2 MPEG4
720 × 480 pixels 320 × 240 pixels
6 1
224 64
50.4 8.1
1012
M. Sueoka et al. / Fusion Engineering and Design 82 (2007) 1008–1014
Fig. 3. The time schedule of the plasma movie capturing system.
(2) When received the “discharge starts signal”, the action is to record a plasma movie. (3) When received the “plasma has been terminated signal”, the action is to start the data compression and to wait for the next 1 min signal. For the case of abnormal event occurred in the system, we have prepared proper measures: if this system receives the unexpected signal, such a signal is ignored. If this system cannot receive the “discharge starts signal”, the movie starts recording the movie automatically 60 s after the 1 min signal. If this system cannot receive the “plasma has been terminated signal”, it stops automatically 67 s after starting a record.
5. Plasma movie database and the web server Under the control of discharge sequences, the following two types of movie data files are produced with the JT-60 shot number; (1) the high resolution MPEG2 movie file in RAID, and (2) the low resolution MPEG4 movie file in the web server. Table 2 shows the number of movie files stored in the movie file can access RAID directly, and can read the latest plasma movie file. The plasma movie web server deals with the MPEG4 movie file transferred from PMCS. A user can download the plasma movie file from the web site as not shown in Fig. 4. This web site update cycle is not synchronized with the discharge sequence.
This web server has two functions for an administrator; (1) he/she can register a new user, and edit/delete the user information, and (2) he/she edit/delete the plasma movie file for maintenance. PMDS has been operated since November 2005, and has already stored about 1200 shot files in the database. This system has succeeded in providing movie data efficiently to all network users on site. 6. A new real-time plasma visualization system The raw high-resolution digital picture is changed to NTSC-based signal by the scanning line converter in order to record a picture by a general video recorder. In this process, the picture quality deteriorates so much in particular, for a plasma CG picture. To record the data with keeping the picture quality, we have to change the analog-signal-based system (NTSC) to the digital one (HDTV or HDV: high-definition digital video recording, 1440 × 1080 pixels). To solve this issue, the new system is proposed in this section, as shown in Fig. 5. In this development, we are exploring to build a system without a dedicated real-time OS like VxWorks. This attempt can also contribute toward avoiding high expense to such a basic computer software cost. The new system has been designed to be able to execute high-speed CG processing. We have employed a fast CPU (3.80 GHz dual) with large core memory (2 GB), and with a high-resolution graphics board for
Table 2 The specification of plasma movie database Item
Operating system
Disk volume
Compression method
Plasma movie capturing system Plasma movie web server
Windows XP Linux
223 GB (5,000 shots) 134 GB (20,000 shots)
MPEG2* MPEG4*
*
Movie player software (for MPEG compression): real player, quick-time player, etc.
M. Sueoka et al. / Fusion Engineering and Design 82 (2007) 1008–1014
1013
Fig. 4. Cover page view of the PMDS web site.
HDTV. As a result, we have achieved fast shape CG with this system (approximately 64 pictures/s). In the future, to exclude the scanning line converter from this system, we plan to input the video signal in the HDTV standard for full digital PMDS, as shown in Fig. 6.
Fig. 6. Future plan of picture signal conversion.
7. Concluding remarks
Fig. 5. Comparison of the existing and new RVS.
The plasma movie database system has already been recognized as a useful tool for the plasma data analysis in JT-60. One, for example, can easily observe a hot spot on the first wall or on the divertor plates together with the plasma shape and separatrix line. Sometimes flakes toroidally flying in the plasma and visible light emission from the plasma is observed synchronously with a sound reflecting internal macroscopic instabilities. Two types of movie data are prepared in this system for various users: high-resolution MPEG2 movie files (50 MB/shot) and lower resolution MPEG4 movie files (8 MB/shot). RAID can keep 5000 shots/20,000 shots for MPEG2/MPEG4, respectively. An MPEG4 movie file can be downloaded within a few seconds. To improve the picture quality, HDV-based digital picture system is now being developed for RVS. A real-time
1014
M. Sueoka et al. / Fusion Engineering and Design 82 (2007) 1008–1014
visualization has been successfully demonstrated without a real-time operating system. Acknowledgements The authors wish to thank Dr. N. Hosogane and members of the Tokamak Control Group in JAEA for their encouragement, support and useful advice.
References [1] R. Felton, E. Joffrin, A. Murari, L. Zabeo, F. Sartori, F. Piccolo, et al., Fusion Eng. Des. 74 (2005) 561–566. [2] J.A. Leuer, R.D. Deranian, J.R. Ferron, D.A. Humphreys, R.D. Johnson, B.G. Penaflor, et al., Fusion Eng. Des. 74 (2005) 665–669. [3] G. Raupp, K. Behler, G. Neu, R. Merkel, W. Treutterer, D. Zasche, et al., Fusion Eng. Des. 60 (2002) 353–359. [4] K. Kurihara, Fusion Eng. Des. 51–52 (2000) 1049–1057.
The plasma movie database system for JT-60 Michiharu Sueoka a,∗ , Yoichi Kawamata a , Kenichi Kurihara a , Akiyuki Seki b a b
Japan Atomic Energy Agency, Fusion Research and Development Directorate, 801-1 Mukoyama, Naka-shi, Ibaraki-ken 311-0193, Japan Japan Atomic Energy Agency, Information Technology Systems’ Management and Operating Office, 2-4 Shirane, Shirakata, Tokai-mura, Naka-gun, Ibaraki-ken 319-1195, Japan Received 10 August 2006; received in revised form 26 February 2007; accepted 26 February 2007 Available online 30 March 2007
Abstract The real-time plasma movie with the computer graphics (CG) of plasma shape is one of the most effective methods to know what discharge have been made in the experiment. For an easy use of the movie in the data analysis, we have developed the plasma movie database system (PMDS), which automatically records plasma movie according to the JT-60 discharge sequence, and transfers the movie files on request from the web site. The file is compressed to about 8 MB/shot small enough to be transferred within a few seconds through local area network (LAN). In this report, we describe the developed system from the technical point of view, and discuss a future plan on the basis of advancing video technology. © 2007 Elsevier B.V. All rights reserved. Keywords: JT-60; Real-time; Plasma; Shape; Movie; Database; Web site; Video technology; CG; NTSC; MPEG2/MPEG4
1. Introduction The world tokamak fusion devices have exploited advanced reactor scenarios by optimizing plasma control methods [1–3]. In their experiments, efficient evaluation is one of the key issues for fast understanding of plasma performance. As a solution, we have provided a real-time plasma movie for the large monitor TV in the JT-60 central control room since 1997. This movie is composed of three elements: a video cam∗ Corresponding author. Tel.: +81 292707423; fax: +81 292707459. E-mail address: [email protected] (M. Sueoka).
0920-3796/$ – see front matter © 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.fusengdes.2007.02.026
era picture, the plasma shape computer graphics (CG) calculated by the plasma shape reconstruction system (PSRS) [4], and a sound (audio amplified signal of magnetic probe voltage). This movie makes it possible for us to compare the video camera picture and the plasma shape CG in a single monitor view. If this movie can be easily replayed even after the discharge shot, such a visual material could provide useful information to the physicists efficiently. For this motivation, we have developed the plasma movie database system (PMDS) having the following features: (1) small data size movie with low resolution is prepared for fast transfer through LAN after the shot and (2) larger data size movie with high res-
M. Sueoka et al. / Fusion Engineering and Design 82 (2007) 1008–1014
olution is also prepared to check the performance of real-time plasma position control algorithms and shape calculation, and to check machine safety. We are considering to improve the picture quality by developing a new real-time visualization system (RVS) producing full-digital CG together with high definition television (HDTV) standard. We believe PMDS might be one of the essential elements for a tokamak power reactor.
2. Configuration of the plasma movie database system (PMDS) Hardware configuration of PMDS is illustrated in Fig. 1. The plasma video camera picture is taken by a standard video camera, equipped at the viewing port of the vacuum vessel looking at a plasma poloidal cross section. RVS for the plasma shape CG (25 ms/shape) is linked with PSRS for shape reconstruction (1 ms/shape) through the reflective memory network. This system outputs the digital picture signal (RGB) to the scanning line converter using the optical fiber cables as indicated in a dotted line in Fig. 1. The scanning line converter changes an RGB signal into lower scanning line analog-signal (NTSC: the National Television Systems Committee), and output this NTSC to the multiple views composer. The composer combines the plasma video camera picture and plasma shape CG into one view as shown in Fig. 2. This composer, available on the market, trims the halves of two different NTSC-based screens, and merges them into one view. The combined NTSC signal is displayed on the large monitor TV and is input to the plasma movie capturing system (PMCS). A raw voltage signal from a magnetic pick-up coil is also input to the sound channel via an audio amplifier. PMCS receives the timing signal according to the JT-60 discharge sequence, and controls the management tasks to handle movie files. In addition, this system executes two types of compression, MPEG2 and MPEG4, for an effective database operation. The MPEG4 movie file is transferred to the plasma movie web server, while the MPEG2 movie file is stored in the RAID (redundant array of inexpensive disks). The plasma movie web server provides a web site dealing with the selection of plasma movie specified by
1009
the JT-60 shot number. A user who wants to observe the movie may access the web site for download of a movie file. The detailed system specifications will be presented in the following sections. 3. Production of the plasma movie data The plasma movie includes the video picture, shape CG, and the sound, as mention above. Each element is quickly explained below: (1) Plasma video picture: The original signal of this picture is based on NTSC standard which is employed for analog television signal standard in Canada, Japan, South Korea, the United States, etc. The specification of this signal is 640 × 480 pixels in resolution and 30 frames per second in speed. (2) Computer graphics of plasma shape: A plasma shape is calculated in the 1 ms cycle using the shape reconstruction method (the CCS (Caushy condition surface) method [4]) by the plasma shape reconstruction system. These pictures produced by RVS show plasma shape together with time evolution of plasma current. This picture has 1000 × 1000 pixels in resolution. (3) Sound data: This sound signal provides the magnetic field fluctuations measured by a magnetic probe sensor equipped in the vacuum vessel. This sound implies various plasma states: changes in plasma rotation speed appears to be a change in the tone of sound. A stable plasma produces smooth high tone as a plasma rotates at a constant speed. On the other hand, an unstable plasma appears to be noisy low tone as a plasma rotates at an irregular speed. 4. Plasma movie capturing system (PMCS) Since the combined movie signal is captured in a computer system, the size of movie data should be discussed the first. The original (not compressed) movie data requires huge disk volume. For example, the estimate of this file size for 1 s is: 640 × 480 pixels × 3 bytes (24 bit full-color) × 30 frames = 27.5 MB. For 1 min discharge, 27.5 MB/s × 65 s = 1.8 GB in total.
1010
M. Sueoka et al. / Fusion Engineering and Design 82 (2007) 1008–1014
Fig. 1. Hardware configuration of the plasma movie database system.
Since the data amount is considerably large, the NTSC-based movie must be compressed to MPEG2based movie. The system converts NTSC to MPEG2, and records the resultant MPEG2 movie file automatically in its own disk using the movie capture board (MVR-D2200V manufactured by Canopus Co., Ltd.).
The MPEG2 movie file amount is about 50 MB/shot for 65 s discharge. RAID stores MPEG2 movie file for 250 experiment days (5000 shots) including the back-up data. Immediately after the system complete recording MPEG2 movie, it starts converting from MPEG2 to MPEG4
M. Sueoka et al. / Fusion Engineering and Design 82 (2007) 1008–1014
1011
Fig. 2. An example view of the plasma movie.
using the movie compression software (ProCorder2.0 manufactured by Canopus Co., Ltd.). The MPEG4 movie file amount is about 8 MB/shot for 65 s discharge. This conversion time requires approximately 4–5 min using Pentium4 (3.8 GHz) CPU with 1 GB core memory. When the conversion is completed, the system transfers an MPEG4 movie file to the plasma movie web server. The plasma movie web server’s disk stores an MPEG4 movie file for 1000 experiment days (20,000 shots). The difference of the specification for MPEG2 and MPEG4 is shown in the Table 1. The employed specification of MPEG2 resolution (720 × 480 pixels) is as good as the S-VHS video, and is better than NTSC (640 × 480 pixels: VGA (video graphics array)). Although higher quality MPEG2 specification corresponding to HDTV
(1920 × 1080 pixels) could be available, we adopted standard MPEG2, because the original signal is categorized in low-resolution picture. MPEG4 can be handled in many free video player software. Since an MPEG4 movie file is transferred through LAN, we chose resolution 320 × 240 pixels (Quarter VGA) which is smaller than MPEG2 not only in resolution but also in the video bit rate. The system automatically records plasma movie according to the timing signal of JT-60 discharge sequence. The time schedule is shown in Fig. 3. This system receives three timing signals. The actions to each signal are shown below: (1) When received the “1 min before discharge signal”, the action is to prepare the record.
Table 1 The specification of a recorded file Compression method
Resolution
Video bit rate (Mbps)
Audio bit rate (Kbps)
Estimate file size (65 s) (MB)
MPEG2 MPEG4
720 × 480 pixels 320 × 240 pixels
6 1
224 64
50.4 8.1
1012
M. Sueoka et al. / Fusion Engineering and Design 82 (2007) 1008–1014
Fig. 3. The time schedule of the plasma movie capturing system.
(2) When received the “discharge starts signal”, the action is to record a plasma movie. (3) When received the “plasma has been terminated signal”, the action is to start the data compression and to wait for the next 1 min signal. For the case of abnormal event occurred in the system, we have prepared proper measures: if this system receives the unexpected signal, such a signal is ignored. If this system cannot receive the “discharge starts signal”, the movie starts recording the movie automatically 60 s after the 1 min signal. If this system cannot receive the “plasma has been terminated signal”, it stops automatically 67 s after starting a record.
5. Plasma movie database and the web server Under the control of discharge sequences, the following two types of movie data files are produced with the JT-60 shot number; (1) the high resolution MPEG2 movie file in RAID, and (2) the low resolution MPEG4 movie file in the web server. Table 2 shows the number of movie files stored in the movie file can access RAID directly, and can read the latest plasma movie file. The plasma movie web server deals with the MPEG4 movie file transferred from PMCS. A user can download the plasma movie file from the web site as not shown in Fig. 4. This web site update cycle is not synchronized with the discharge sequence.
This web server has two functions for an administrator; (1) he/she can register a new user, and edit/delete the user information, and (2) he/she edit/delete the plasma movie file for maintenance. PMDS has been operated since November 2005, and has already stored about 1200 shot files in the database. This system has succeeded in providing movie data efficiently to all network users on site. 6. A new real-time plasma visualization system The raw high-resolution digital picture is changed to NTSC-based signal by the scanning line converter in order to record a picture by a general video recorder. In this process, the picture quality deteriorates so much in particular, for a plasma CG picture. To record the data with keeping the picture quality, we have to change the analog-signal-based system (NTSC) to the digital one (HDTV or HDV: high-definition digital video recording, 1440 × 1080 pixels). To solve this issue, the new system is proposed in this section, as shown in Fig. 5. In this development, we are exploring to build a system without a dedicated real-time OS like VxWorks. This attempt can also contribute toward avoiding high expense to such a basic computer software cost. The new system has been designed to be able to execute high-speed CG processing. We have employed a fast CPU (3.80 GHz dual) with large core memory (2 GB), and with a high-resolution graphics board for
Table 2 The specification of plasma movie database Item
Operating system
Disk volume
Compression method
Plasma movie capturing system Plasma movie web server
Windows XP Linux
223 GB (5,000 shots) 134 GB (20,000 shots)
MPEG2* MPEG4*
*
Movie player software (for MPEG compression): real player, quick-time player, etc.
M. Sueoka et al. / Fusion Engineering and Design 82 (2007) 1008–1014
1013
Fig. 4. Cover page view of the PMDS web site.
HDTV. As a result, we have achieved fast shape CG with this system (approximately 64 pictures/s). In the future, to exclude the scanning line converter from this system, we plan to input the video signal in the HDTV standard for full digital PMDS, as shown in Fig. 6.
Fig. 6. Future plan of picture signal conversion.
7. Concluding remarks
Fig. 5. Comparison of the existing and new RVS.
The plasma movie database system has already been recognized as a useful tool for the plasma data analysis in JT-60. One, for example, can easily observe a hot spot on the first wall or on the divertor plates together with the plasma shape and separatrix line. Sometimes flakes toroidally flying in the plasma and visible light emission from the plasma is observed synchronously with a sound reflecting internal macroscopic instabilities. Two types of movie data are prepared in this system for various users: high-resolution MPEG2 movie files (50 MB/shot) and lower resolution MPEG4 movie files (8 MB/shot). RAID can keep 5000 shots/20,000 shots for MPEG2/MPEG4, respectively. An MPEG4 movie file can be downloaded within a few seconds. To improve the picture quality, HDV-based digital picture system is now being developed for RVS. A real-time
1014
M. Sueoka et al. / Fusion Engineering and Design 82 (2007) 1008–1014
visualization has been successfully demonstrated without a real-time operating system. Acknowledgements The authors wish to thank Dr. N. Hosogane and members of the Tokamak Control Group in JAEA for their encouragement, support and useful advice.
References [1] R. Felton, E. Joffrin, A. Murari, L. Zabeo, F. Sartori, F. Piccolo, et al., Fusion Eng. Des. 74 (2005) 561–566. [2] J.A. Leuer, R.D. Deranian, J.R. Ferron, D.A. Humphreys, R.D. Johnson, B.G. Penaflor, et al., Fusion Eng. Des. 74 (2005) 665–669. [3] G. Raupp, K. Behler, G. Neu, R. Merkel, W. Treutterer, D. Zasche, et al., Fusion Eng. Des. 60 (2002) 353–359. [4] K. Kurihara, Fusion Eng. Des. 51–52 (2000) 1049–1057.