BNL, Upton, New York, USA
The fast extraction kicker system at AGS to RHIC transport line uses Stanford Research DG535 delay generators to time, synchronize, and trigger charging power supplies and high-level thyratron trigger pulse generators. This timing system has been upgraded to use an SRS DG645 instrument due to reliability issues with the aforementioned model and slow response time of GPIB buses. The new model provides the relative timing of the separate kicker modules of the assembly from a synchronized external trigger with the RF system. Specifications of the timing scheme, an algorithm to load settings synchronized with RHIC real-time events, and performance analysis of the software will be presented in the paper.
BNL, Upton, New York, USA
In RHIC low energy bunched beam cooling experiment, LEReC, a 704 MHz fiber laser is modulated such that when striking a photocathode, it produces corresponding electron bunches which are accelerated and transported to overlap an ion beam bunched at 9 MHz RF frequency The need for precise timing is handled well by the existing infrastructure. A layer of software application called the timing manager has been created to track the LEReC beam concerning the RHIC beam and allow instruments to be fired in real-time units instead of bunch timing or RHIC turns. The manager also automates set-tings of different modes based on the RF frequency and maintains the timing of instrumentation with a beam. A detailed description of the bunch structure and scheme of synchronizing the RF and laser pulses will be discussed in the paper.
BNL, Upton, New York, USA
This paper reports on development of a general purpose image analysis application, tailored for beam profile monitor cameras of RHIC Collider-Accelerator complex. ImageViewer is pure Python application, based on PyQtGraph and SciPy packages. It accepts image stream from a RHIC image manager (optionally from an EPICS areaDetector driver, or from the file system). The standard analysis includes recognition of connected objects; for each object the parameters of a fitted ellipsoid (position, axes and tilt angle) are calculated using 2nd-order image moments, the parameters then corrected using gaussian fit of the object and a surrounding background. Other features supported: saving, image rotation, region of interest, projections, subtraction of a reference image, multi-frame averaging, pixel to millimeter calibration. Playback feature allows for fast browsing and cleanup of the saved images. User add-ons can be added dynamically as included modules. Each camera of the RHIC complex is equipped with a server (grahic-less) version of this application, providing the same analysis and publishing calculated parameters to RHIC Controls Architecture.
BNL, Upton, New York, USA
The BNL CA-D controls environment has recently been adopting modern programming languages such as Python. A new framework has been created to instantiate setting and measurement parameters in Python as an alternative to C++ and Java process-variable-like objects. With the help of automated testing tools such as pyTest and Coverage, a test suite is generated and executed before the release of Python-based accelerator device objects (ADO) to assure quality as well as compatibility. This suite allows developers to add custom tests, repeat failed tests, create random inputs, and log failures.
BNL, Upton, New York, USA
Modern instruments are often supplied with rich proprietary software tools, which makes it difficult to integrate them to an existing control systems. The liteServer is very lightweight, low latency, cross-platform network protocol for signal monitoring and control. It provides very basic functionality of popular channel access protocols like CA or pvAccess of EPICS. It supports request-reply patterns: ’info’, ’get’ and ’set’ requests and publish-subscribe pattern: ’monitor’ request. The main scope of the liteServer is: 1) provide control and monitoring for instruments supplied with proprietary software, 2) provide fastest possible Ethernet transactions, 3) make it possible to implement in FPGA without CPU core. The transport protocol is connection-less (UDP) and data serialization format is Universal Binary JSON (UBJSON). The UBJSON provides complete compatibility with the JSON specification, it is very efficient and fast. A liteServer-based system can be connected to existing control system using simple bridge program (bridges for EPICS and RHIC Ado are provided).
