# Presentation: 769832

## SNS VACUUM INSTRUMENTATION AND CONTROL SYSTEMS*

- _J. Y. Tang_, L.A. Smart and H.C. Hseuh, Brookhaven National Laboratory, Upton, NY, USA
- P. S. Marroquin and L. R. Dalesio, Los Alamos National Laboratory, Los Alamos, NM, USA
- S. A. Lewis and C. A. Lionberger, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- K. Kishiyama, Lawrence Livermore National Laboratory, Livermore, CA, USA
- D. P. Gurd and M. Hechler, Oak Ridge National Laboratory, Oak Ridge, TN, USA
- W. Schneider, Thomas Jefferson National Accelerator Facility, Newport News, VA, USA

_***Abstract***_* **The Spallation Neutron Source (SNS) vacuum instrumentation and control systems are being designed at Lawrence Berkeley National Laboratory (LBNL), Brookhaven National Laboratory (BNL), Thomas Jefferson National Accelerator facility (TJNAF) and Los Alamos National Laboratory (LANL). Each participating lab is responsible for a different section of the machine: LBNL for the Front-End section, LANL for the warm LINAC section, TJNAF for the cold LINAC section and BNL for the Ring and transfer line sections. The vacuum instrumentation and control systems are scheduled to be installed and be in operation at Oak Ridge National Laboratory in 2004 or 2005. Although the requirements vary for different sections of the machine, a collaborative effort has been made to standardize vacuum instrumentation components and the global control system interfaces. This paper summarizes the design of each sub-section of vacuum instrumentation and control system and discusses SNS standards for Ion Pump and Gauge controllers, Programmable Logic Controller (PLC) interfaces, Ladder Logic programming and the SNS global control system interfaces.*

_***Summary  ***_The SNS vacuum instrumentation and control system is a cooperative endeavor among six DOE Labs. A major effort on standardization among SNS vacuum subsystems has been made with the aim of easing commissioning, maintenance and upgrade work. The following areas of standardization have be turned out to be successful among the major sections of the machine:
- Instrumentation components
- Control system architecture
-  Naming conventions
- As of now, the Front-End vacuum subsystem has been completed while the rest is still under development, with hardware procurements in progress for Warm Linac and the Ring subsystems. The collaborative effort is still critical to the final success of SNS vacuum instrumentation and controls for commissioning in 2005.

_***SNS Vacuum Level Requirements***_
**Front End (FE)****	****	****	****	****	****	****	****1********10****-4  ****to  4x10****-7 ****Torr**** **
**Drift Tube Linac (DTL)****	****	****	****	****	****2x10****-7 ****Torr**** **
**Coupled Cavity Linac (CCL)****	**			**5x10****-8 ****Torr**** **
**Superconducting Linac****	****	****	****	****	****	****<1x10****-9 ****Torr**** **
**High-Energy Beam Transport line (HEBT)****	****5x10****-8 ****Torr**
**Ring****	****	****	****	****	****	****	****	****	****1x10****-8 ****Torr**** **
**Ring to Target Beam Transport line (RTBT)****	****1x10****-7 ****Torr**** **

_***References***_
- [1] H.C. Hseuh, C. J. Liaw and M. Mapes, “Design of the SNS Accumulator Ring Vacuum Systems”, PAC’99, New York, p1345 (1999)
- [2] S. A. Lewis and C. A. Lionberger., “Status of the Control System for the Front-End of the Spallation Neutron Source”, this conference
- [3] J.Y. Tang, et al., “A Distributed and Collaborative PLC Lab for SNS”, ICALEPCS’99, Trieste, Italy, p370 (1999)
- [4] http://www.controlnet.org/
- [5] H. C. Hseuh, L. A. Smart and J. Y. Tang, “Design and Development of the SNS Ring Vacuum Instrumentation and Control Systems”, PAC’01, Chicago, (2001)
- [6] K. U. Kasemir and L. R. Dalesio, “Interfacing the ControlLogix PLC over EtherNet/IP”, this conference

-  The principal function of the PLC is to provide control of the sector gate valves that sectionalize the vacuum system. The vacuum PLCs will also provide interlock outputs to MPS and RF systems and receive inputs from target system. Data exchange between PLCs is accomplished through a real-time, redundant-media ControlNet network [4]. The high-speed, deterministic ControlNet network is ideal for transmitting time-critical vacuum interlock information and real-time control.
-  The primary function of the IOC is to provide the gateway between the SNS global control system and vacuum instrumentation system. The PLCs will communicate with the IOCs through Ethernet [6].
-  The gauge controllers and ion pump controllers are linked via the serial 485 bus. Configuration of the controllers or monitoring non-time-critical information will be done through IOCs via the 485 serial lines.
-  The ion pump controllers and the gauge controllers are standardized through out the Warm Linac, the Ring and the beam transfer lines.