Due to radiation emitting from beam and high voltage; a remote control system which is capable of producing/adjusting beam parameters, carrying out related measurements and taking safety measures is mandatory.
This remote system should form a workbench for operator to carry out all-scale beam control as well as additional features like data storing for offline analysis and debugging/maintenance for whole system, temporary safe data and privilege transfer for additional sources, monitor and control of auxiliary systems like water or helium, form an interlock mechanism for human and machine safety and to prevent predefined possible operator errors like collisions of feed-troughs or mistimed state changes of vacuum valves .
Apart form the features sampled above, in order to achieve maximum performance control system must also satisfy some conditions like real-time data communication and time tagging, being fail-safe, being expandable and flexible, being distributed and having minimum downtime.
System Design and development is divided into five segments as follows and studies are ongoing among all in a parallel manner.
- Architectural and Conceptual Design (finished)
- Hardware requirements and hardware standardization
- Software structure design (finished)
- Network design
- Raw code and device support development
TARLA control system development is ongoing and aimed to follow a time-line parallel to beamline installation.
TARLA e-gun test stand is a 250 kV dc gun which is the exact replica of the main gun. This replica combined with a prototype beamline structure gives the opportunity to study beam properties and beamline technologies like vacuum, cooling, data collection etc. Despite being very low compared to actual machine, radiation levels and high voltage risk does not allow local operation. For this reason a smaller control system for test stand which satisfies all the requirements listed for actual machine is developed.
Test stand control system is developed in Labview environment and has the following capabilities;
– remote control of 3 programmable power supplies, a master oscillator(homemade), three remote controlled potentiometer (homemade) where all of these devices are operated under high voltage, therefore no direct connection is possible
– remote control of three step motors
– remote control of two pneumatic valves
– remote control of 7 programmable power supplies including one 350kV device
– Image acquisition via 3 GigE cameras
– vacuum measurement from 3 pumps as analog voltage with resolution of 50 uV
– vacuum measurement by a gauge controller
– image processing for transverse beam size and emmittance measurements
– GUI design suited for a single 23” screen for single operator with full functionality
– a soft interlock for human protection regarding HV level, radiation level and physical access
– save/load parameters option
– data logging and online/offline graphical data viewer up to 5 different sets of data
– alarm handling
– a dedicated camera control module for exposure, rate, brightness etc. control and hysteresis measurements
– independent, parallel layered structure for debugging mode and reduced feature operations
This Labview based system also serves as a multi-faced model for a EPICS based system providing valuable feedback for data communication, operator demands, possible point of failures, speed requirements, operation/downtime ratios etc.
By the help of experience gained from Labview based one which is in operation since February 2013, the alpha version of EPICS based test stand control is released in March 2014 that is capable of producing CW beam in full scale range but lacking the additional features like camera control or data logging.