OAK-B135 The installation of new internal magnetic coils (I-Coils) in the DIII-D tokamak at General Atomics required extensive additions to the experiment data acquisition and protection capabilities. This set of 12 coils (up to 7 kA each) is designed to allow improved feedback stabilization of resistive wall modes which limit the plasma performance. The acquisition and signal conditions needs of the I-Coil power system presented an opportunity to try a new data acquisition approach which increased both the sampling rate and sample size per channel compared to the standard DIII-D CAMAC acquisition equipment. A 96 channel Compact-PCI (cPCI) digitizer system was purchased for the I-Coil project to acquire up to approximately 380 MB of power supply and coil current data per plasma discharge. Additional instrumentation and control was provided to protect personnel, the new coils, the tokamak, the facility and improve machine availability. This paper will present discussions of technical and programmatic requirements, based for requirements, the design selection outcome, installation experience, integration issues, commissioning experience, and lessons learned. The data acquisition system is described in detail including a conservative signal isolation scheme, signal grounding standards, anti-aliasing filters, and synchronization of acquisition. Protection interlocks are described, including high voltage isolation, water flow measurement, and the coil grounding-shorting switches

Anderson, P. M.

Campbell, G. L.

Jackson, G. L.

Kellman, A. G.

Kellman, D. H.

Piglowski, D. A.

Szymanski, D. D.

UNT Digital Library

GA-A24464 DATA ACQUISITION AND PROTECTION FOR NEW DII-D IN-VESSEL COILS by G.L. CAMPBELL, D.D. SZYMANSKI, D.A. PIGLOWSKI, D.H. KELLMAN, P.M. ANDERSON, G.L. JACKSON, and A.G. KELLMAN MARCH 2004 DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. a G A-A24464 DATA ACQUISITION AND PROTECTION FOR NEW DII-D IN-VESSEL COILS by G.L. CAMPBELL, D.D. SZYMANSKI, D.A. PIGLOWSKI, D.H. KELLMAN, P.M. ANDERSON, G.L. JACKSON, and A.G. KELLMAN This is a preprint of a paper presented at the 20th IEEEINPSS Symposium on Fusion Engineering, San Diego, California, October 14-17, 2003 and to be published in Fusion Science and Technology. Work supported by the US.  Department of Energy under Contract No. DE-AC03-99ER54463 GENERAL ATOMICS PROJECT 30033 MARCH 2004 Data Acquisition and Protection for New DIII-D In-Vessel Coils G.L. Campbell, D.D. Szymanski, D.A. Piglowski, D.H. Kellman, P.M. Anderson, G.L. Jackson, A.G. Kellman General Atomics, P.O. Box 85608, San Diego, California 92186-5608 Abstract. The installation of new internal magnetic coils (I- Coils) in the DIII-D tokamak at  General Atomics required extensive additions to the experiment data acquisition and protection capabilities. This set of 12 coils (up to7 kA each) is designed to allow improved feedback stabilization of resistive wall modes which limit the plasma performance. The acquisition and signal conditioning needs of the I-Coil power system presented an opportunity to try a new data acquisition approach which increased both the sampling rate and sample size per channel compared to the standard DIII-D CAMAC acquisition equipment. A 96 channel Compact-PCI (cPCI) digitizer system was purchased for the I-Coil project to acquire up to approximately 380 MB of power supply and coil current data per plasma discharge. Additional instrumentation and control was provided to protect personnel, the new coils, the tokamak, the facility and improve machine availability. This paper will present discussions of technical and programmatic requirements, bases for requirements, the design selection outcome, installation experience, integration issues, commissioning experience, and lessons learned. The data acquisition system is described in detail including a conservative signal isolation scheme, signal grounding standards, anti-aliasing filters, and synchronization of acquisition. Protection interlocks are described, including high voltage isolation, water flow measurement, and the coil grounding-shorting switches. I. INTRODUCTION The DIII-D project has installed twelve new internal coils (I-Coils) inside of the tokamak vacuum vessel. These coils permit flexible error field compensation and resistive wall mode (RWM) feedback stabilization [ I ] .  The coils are designed to operate at up to 7 KA and are water-cooled. Five DC supplies and four switching power amplifiers (SPAs) supply coil current via a patch panel. Commands from the DIII-D plasma control computer system set coil currents in real time to achieve the desired plasma response. Data acquisition, control and protection requirements were established to accommodate experimental needs and assure investment protection. 11. FUNCTIONS AND REQUIREMENTS A. I-Coil data acquisition functions are: Acquire I-Coil power supply data (current, voltage and commands for 5 DC supplies and 4 SPAs) Acquire 12 I-Coil currents Acquire power supply and SPA commands from the plasma control system Interface to DIII-D data acquisition system 0 Make data available to shot-data archive B. Acquisition performance requirements include: Measure coil currents to 10 A accuracy Measure power supply and SPA currents and voltages with accuracy sufficient to assess power supply performance Acquired data shall be available for display immediately after the shot in the same manner as all other DIII-D data Data shall be sampled at 20 Hz to 100 KHz. Note: In order to achieve the temporal resolution for SPA performance analysis, voltages from those supplies needed to be acquired at with 50 ISHz bandwidth. This is the highest bandwidth required for the I-Coil systems. Data shall be acquired at maximum sample rate for at least 10 s. Data sample clock shall be synchronized to all other DIII-D acquisition clocks C. Equipment protection functions are. 0 Prevent steam generation Protect interfacing systems Interface to operator Protect I-Coils from over-temperature damage D. Protection system performance requirements are: Water flow must be adequate to each coil for shot setup to be allowed to proceed. Water temperature at outlet must be acceptably low for each coil for shot setup to be allowed to proceed. Coil temperature must be acceptably low for each coil or the shot shall be aborted. coils and power cables and instrumentation systems. 0 5000V of isolation shall be provided between the LI 111. DATA ACQUISITION DESIGN SOLUTION Most of the data acquisition on the DIII-D experiment is implemented with computer automated measurement and control (CAMAC) hardware. This infrastructure has existed since the beginning of this project in 1978. For the most part, these systems meet performance requirements. They could have been used for the I-Coil data acquisition. However, many of our CAMAC components are becoming obsolete and unserviceable. VME and PCI systems have already been used at DIII-D for newer acquisition systems [2]. PCI is successfully deployed for the plasma control system. Plasma control is in a relatively benign environment near the control room. The best place to locate the I-Coil acquisition system is out in the power supply area, which is not environmentally controlled. For this reason we thought it best to consider CAMAC or compact PCI (cPCI). A rough cost comparison GENERAL ATOMICS REPORT GA-A24464 I DATA ACQUISITION AND PROTECTION FOR NEW DIII-D IN-VESSEL COILS between an all-new CAMAC installation and a cPC1 installation was done which showed cPCI as the less expensive of the two solutions by about 20%. Even though cPCI was considered to present more schedule risk, we decided to adopt that solution. Also, it is considered important for the project to migrate away from CAMAC to more serviceable acquisition and control platforms. This single deployment of a cPCI acquisition system does not set a precedent for future systems on DIII-D, but has given us more experience with what G.L. CAMPBELL, et nl. CQ CLOCK CL.1COU.S FROM ANNEX CLOCK CL~tCOlL.FFROU ANNEX alternatives there are. Future design solutions for acquisition and control on this project will be driven by performance IX BLOCKCABLE INTERFACE requirements, as this one was. PCI and cPCI are attractive now due to their market predominance. Indeed, some PCI components are now just commodities, a status never realized by VME or CAMAC. The I-Coil data acquisition system is shown in Fig. 1. Assembly details of the acquisition computer are in Fig. 2. The computer supports three 32-channel digitizer cards with a 1 GHz Pentium CPU running LINUX. Data is transferred after a shot via an Ethernet TCP/IP connection to be included in all other DIII-D shot data [31. The digitizers support UP to 250 Ksamplels operation and each has 128 MB memory on the digitizer card. The vendor, DTAQ Solutions Ltd., supplied an additional board for each 32-channel digitizer that provides an anti-aliasing filter for 50 KHz, and input protection Up to 100 v channel to channel or channel to ground. Outboard of the acquisition computer we installed isolation amps on some channels to eliminate ground loops. We had very good success with the commissioning of this system. Since it was delivered already configured by the vendor, we essentially had only to connect our signals and get the data out. The sole significant challenge was a stop trigger problem resulting in apparent channel swapping of the data. We understood that the stop trigger was latched and asserted on the next clock transition. This is not the case; the stop trigger must span the duration of one sampling clock period to assure it is there when the appropriate clock edge arrives. A pulse stretcher after our standard timing receiver filled this requirement and eliminated the observed abnormalities in the data (Fig. 3). Fig. 2. I-Coil acquisition computer assembly. A clean environment is maintained for the I-Coil acquis i t ion system by installation in a sealed and air- conditioned rack. The computer and expensive digitizers are protected from heat removal failure by the system diagrammed in Fig. 4. When in-cabinet temperature exceeds 92"F, the input power to the UPS will be interrupted. Subsequently, the UPS will send a message to the computer to shut down. The UPS will run out in about 7 min, giving the computer tirne to shut down but not enough time to raise the cabinet temperature than 2 -30~  above 920, IV. COIL PROTECTION INTERLOCKS DESIGN SOLUTION Fig. 5 shows the equipment protection interlock systems for the I-Coils. The design meets requirements for equipment protection as stated earlier. The referenced requirements from Fig. 5 are: 1. 2. 3. Water flow must be adequate to each coil for shot setup to be allowed to proceed. Water temperature at outlet must be acceptably low for each coil for shot setup to be allowed to proceed. Coil temperature must be acceptably low for each coil or the shot shall be aborted. The bases for these requirements are derived from the mechanical design of the coils and interfacing components [4]. The isolation transformer and the long deionized water path satisfy the requirement for 5000 V of isolation between the coils-power cables and instrumentation. V. CONCLUSION Deployment of the data acquisition system was successful although at first perceived risky. It meets requirements at a reasonable cost of about $375 per channel. We look forward to the use of other cPCI solutions with capabilities beyond waveform digitization. These capabilities would include functional replacement of other traditional CAMAC modules that perform digital I/O, timing, counting and others. Fig. 1 .  Context diagram of I-Coil data acquisition system. 2 GENERAL ATOMICS REPORT GA-A24464 G.L. CAMPBELL, et a/. DATA ACQUISITION AND PROTECTION FOR NEW DIII-D IN-VESSEL COILS POWERSUPPLYAREA CONTROL ROOM ANNEX - PULSE STRETCHER I-COIL ACQUISITION SYSTEM T I  TIMING RECEIVER * DIII-D TIMING STOP RIGGERS (3) CPCl IIGITIZER IGITAL IIC SECTION FAST” ACC CLOCK CH 1-32 ‘SLOW” CH 33-96 ICQ uocn DERIVED DIII-D IMHZ CABLE CLOCK Fig. 3. Digitizer clock and stop trigger connections. RS-232 PORT COM 1- AC POWER IN I COIL ACQUISITION SYSTEM [DAQJ] IS0 AMP POWER SUPPLIES RS-232 :OM PORT POWER IN RC POWER AC t- DUT TRIPP-LITE UPS SYSTEM 450VA LOAD CAPACITY NOTE 1 7-15 MINUTE FULL- : LOAD I Note 1: This model ups communicates status to a linux “poweralert” client on DAQ3. The client will shut down the workstation OS in an orderly way if power is lost to the ups input side (ie thermostat trips or facility power outage). The orderly shutdown will complete by the time the ups shuts off loads (approx 7-15 min). I *-.---, DIII-D TIMING AND CLOCKS CLOCK CL-ICOIL-F CLOCK CL-ICOIL-S NOT CONNECTED MECHANICAL THERMOSTAT 25AMP CONTACTS MANUAL RESET OPEN * 92F AC POWER FROM CABINET ISOLATION XFMR ALARM INDICATOR Fig. 4. I-Coil acquisition cabinet over-temperature protection interlock. GENERAL ATOMICS REPORT GA-A24464 3 DATA ACQUISITION AND PROTECTION FOR NEW DIII-D IN-VESSEL COILS OUTLET COPPER TEMP 88C OPENS (NOTE 1) G.L. CAMPBELL, et al. REQUIREMENT 3 (NOTE 5) )C /I OPS ABORT ~ .................... ~ /I 2 /I 2 .P FLOW SWITCHES > 3.0GPM (1 PER COIL) 5KV ISOLATION COIL PROTECTION REQUIREMENT 1 CABINETS ~____--____----------I. 112 (NOTE 4) DOWNSTREAM REQUIREMENT 2 c. - - _ _ _  - - - - - -_ - - - - - - - OUTLET WATER /I 2 TEMP I (NOTE 3) RESET 11 INHIBIT RESET 11 INHIBIT INTERSPACE N2 PRESSURE XMTR >5PSI, <SOPSI (NOTE 6) /6 c VACUUM CONTROL PLC 180 ONLY FLOW METERS 180 ONLY ABORT EPSSIC 1) USING ELMWOOD PART OPENS >88C; CLOSES t77C 2) ELMWOOD TSTATS OPEN >43C; CLOSE t32C 3) EPSSIC WILL NOT RESET IF ABORT IS BAD 4) FLOW AND WATER TEMP SWITCHES SUFFICIENTLY FAR FROM MACHINE THAT 5KV ISOLATION NOT NEEDED 5) REQUIREMENT NUMBERS REFER TO MEMO “PROTOTYPE AND PRODUCTION ICC INTERLOCKS” REV 8/26/02 6) PRESSURE XDCR IS 0-100 PSlA Fig. 5. I-Coil protection interlocks block diagram The equipment protection interlocks are traditional hardwired systems with off-shelf components. The reliability of such a system is easy to define and quantify. The system is also maintainable by a much wider range of personnel with diverse technical training. [2] ACKNOWLEDGMENT Work supported by U.S. Department of Energy Contract NO. DE-AC03-99ER54463. REFERENCES [ l ]  G.L. Jackson, et nl., “Initial results from the new internal magnetic field coils for resistive wall mode stabilization in the DIII-D tokamak,” Proc. of the 30th [4] European Physical Society on Controlled Fusion and Plasma Physics, St Petersburg, Russia, (2003), to be published in the proceedings. D.H. Kellman, et al., “Recent developments in alternatives to CAMAC for data acquisition at DIII-D, these proceedings. D.A. Piglowski, et al., “Advances in distributed data acquisition at DIII-D, proc. of the 4th IAEA Tech. Meeting on Control, Data Acquisition, and Remote Participation for Fusion Research, San Diego, California (2003), to be published in Fusion Eng. and Design. P.M. Anderson, et al.,, Design, fabrication, installation, testing and initial results of in-vessel control coils for DIII-D,” these proceedings. 4 GENERAL ATOMICS REPORT GA-A24464 

DATA ACQUISITION AND PROTECTION FOR NEW DII-D IN-VESSEL COILS

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DATA ACQUISITION AND PROTECTION FOR NEW DII-D IN-VESSEL COILS

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