Experimental Physics And Industrial Control System Research Articles

Development of vertical test stand for SRF cavities at PAPS

The vertical test stand (VTS) plays a crucial role in evaluating the performance of superconducting radio-frequency (SRF) cavities. The VTS at the Platform of Advanced Photon Source Technology R&D (PAPS) has been developed by the Institute of High Energy Physics, Chinese Academy of Sciences (IHEP). In this paper, the digitalization (based on Field Programmable Gate Array, FPGA) and integration functionalities of VTS was carried out, which simplified the vertical test and improved efficiency greatly. Several vertical tests have been conducted at this upgraded VTS successfully, which adopted digital self-excited loop (SEL) and Experimental Physics and Industrial Control System (EPICS).

Design and Implementation of Chopper Control System for HIAF

The chopper control system which is synchronized by the White Rabbit timing network is designed and implemented to meet the requirements of the chopper of ion source for the High-Intensity Heavy Ion Accelerator Facility (HIAF). The hardware system consists of timing modulation controller, waveform acquisition, parameter setting, and remote control of the chopper power supply. The software includes low-level drivers and top-level applications which are based on Experimental Physics and Industrial Control System (EPICS). The combination of hardware and software completes the interaction of timing messages with the White Rabbit network, waveform acquisition, the setting of timing modulation parameters in several running modes, and remote control of the chopper power supply, etc. The test results show that the system can achieve timing modulation with a resolution of 8 ns and waveform acquisition of embedded EPICS IOC (input/output controller) at a 125 MHz sample rate. The design, implementation, and test of the chopper control system are described in this paper.

Design and Implementation of Chopper Control System for HIAF

The chopper control system which is synchronized by the White Rabbit timing network is designed and implemented to meet the requirements of the chopper of ion source for the High-Intensity Heavy Ion Accelerator Facility (HIAF). The hardware system consists of timing modulation controller, waveform acquisition, parameter setting, and remote control of the chopper power supply. The software includes low-level drivers and top-level applications which are based on Experimental Physics and Industrial Control System (EPICS). The combination of hardware and software completes the interaction of timing messages with the White Rabbit network, waveform acquisition, the setting of timing modulation parameters in several running modes, and remote control of the chopper power supply, etc. The test results show that the system can achieve timing modulation with a resolution of 8 ns and waveform acquisition of embedded EPICS IOC (input/output controller) at a 125 MHz sample rate. The design, implementation, and test of the chopper control system are described in this paper.

TLS Fast Orbit Feedback Upgrade

The Orbit Feedback System (OFB) at the Taiwan Light Source (TLS) was implemented two decades ago and has undergone multiple upgrades to enhance its performance. The loop bandwidth was constrained by the available hardware. The system is unable to eliminate perturbations from a fast source. In order to enhance the performance of orbit feedback, the system underwent an upgrade in 2008. The upgrade involved the replacement of the analog-type BPM electronics with digital BPM electronics, as well as the replacement of the corrector power supply with a high-performance switching-type power supply that has a wide bandwidth. Following the commissioning of the Taiwan Photon Source (TPS) in 2015, a decision was made to gradually migrate the control system of the Taiwan Light Source to the Experimental Physics and Industrial Control System (EPICS). This decision was made in order to facilitate resource sharing between the two facilities since EPICS had already been adopted by TPS. The Orbit Feedback System is a revitalized subsystem that now benefits from EPICS support. Additionally, the feedback computation unit has been upgraded to a Field Programmable Gate Array (FPGA), resulting in an increase in the calculating cycle from 2.5 kHz to 10 kHz. This report presents a concise overview of the integration of fast orbit feedback and the outcomes of the orbit stability enhancement following the upgrade.

SuperKEKB personnel protection system

The Super-KEKB[1] personnel protection system (PPS) takes care of not only Super-KEKB accelerator, but also Photon Factory - Advanced Ring (PF-AR), Positron Damping Ring (PDR)[2] and their beam transport lines (BT)[3]. The logic of the PPS has been changed to adapt the new accelerator operation scheme. The Experimental Physics and Industrial Control System (EPICS) was introduced into the PPS. Many tools developed under EPICS environment are used.

The advanced motion control system in HEPS beamline

In synchrotron radiation facilities such as the High Energy Photon Source (HEPS), numerous motorized actuators are equipped on the optics devices of HEPS beamline to manipulate the orientation of crystals and mirrors, thereby altering the position and characteristics of X-rays. The motion control system (MCS) plays an important role in the optics devices of HEPS beamlines, such as monochromator, K-B mirror and sample plants. In order to acquire the specify properties of X-ray and satisfy the complex experimental requirements, MCS must have the ability to handle the complicated control demands. Therefore, HEPS has developed a standardized motion control system for synchrotron radiation applications, which is a distributed system based on EtherCAT fieldbus. The hardware of this system consists of the control unit and driver unit, which has the flexibility to suit for different applications. The software of MCS is designed under the Experimental Physics and Industrial Control System (EPICS), which is very popular in synchrotron radiation facilities all over the world. In this paper, the performance tests of IOC software were demonstrated, and a few flyscan applications were given, which include spiral scan, raster scan and position event trigger, to demonstrate the feasibility and effectiveness of this system.

Real-time radiation monitoring of high energy 1.2-GeV synchrotron accelerator using experimental physics and industrial control system

The high energy 1.2-GeV electron accelerator facility’s radiation detection and monitoring system (RDMS) has greatly evolved to be the effective backbone of real-time radiation monitoring for the new light source 3-GeV synchrotron facility. Experimental Physics and Industrial Control System (EPICS), ethernet hardware connections (Optic fibers), and Web-based software interfaces make up the new RDMS framework, built on well-liked network technology. The problems of monitoring i.e., a lot of manpower, poor monitoring accuracy, and inability to monitor continuously in the high radiation dose are eliminated. EPICS, composed of an Input/Output Controller (IOC) and Client Workstations which can communicate with a Local Area Network (LAN), were applied for remote control and radiation measurement. EPICS has been able to transport and store massive amounts of data for large-scale systems with a wide range and high accuracy. The monitoring data were sent to the server through the optic fibers network system, which is more advantages such as no distance restrictions, low attenuation of the signal, faster responding times, and particularly electromagnetic resistance. The data can be accessed anywhere from client monitors with graphical user interfaces. This system is successfully developed and tested for the high energy 1.2-GeV electron accelerator. The RDMS is useful for radiation safety to monitor the radiation dose level during machine operation to protect occupational workers and the public from radiation hazards.

A study of performance comparison of databases for HALF data archiving system

The Hefei Advanced Light Facility (HALF) is a 2.2 GeV fourth-generation synchrotron radiation light source. The HALF control system is a distributed control system based on Experimental Physics and Industrial Control System (EPICS). As the essential part of the HALF control system, the Historical Data Archiving System (HDAS) is responsible to store operational data for the entire facility including the accelerator and beamlines, and provides the functions for data query and analysis. According to the estimation based on the HALF scale, approximately 25,000 EPICS PVs will be stored in HDAS, and these accumulated massive data require a dedicated database for persistent storage and management. Under the EPICS PV data scenario of HALF, a fair database test platform is designed and built to test the read-write performance of databases commonly used in the particle accelerator field. The tested objects include EPICS Archiver Appliance and the five databases MongoDB, HBase, InfluxDB, TimescaleDB, and Cassandra. Additionally, research on the five databases software ecosystem is conducted for the development and extension of HDAS. The test results indicate that TimescaleDB has the fastest read performance, and 1.4×10^6 items of data can be read per second. TimescaleDB also has superior write performance. 1.2 × 105 items of data can be written per second, which can fully meet the writing requirements of HDAS. Regarding the software ecosystem, TimescaleDB is compatible with a larger number of data visualization software and big data processing frameworks. Therefore, TimescaleDB is more suitable as the HDAS database. In the future, a TimescaleDB distributed cluster will be designed and deployed, and an HDAS prototype system will be developed based on this cluster.

Development of Allison scanner to measure transverse emittance at low energy beam transport of rare-isotope accelerator complex for ON-line experiments

The Rare-isotope Accelerator complex for ON-line experiments is a heavy-ion accelerator facility that accelerates a stable or rare isotope beam up to 400 kW with an energy of 200 MeV/u. Various heavy-ion beams are generated from the Electron Cyclotron Resonance Ion Source, with an energy of 10 keV/u and separated according to A/Q at the first dipole magnet (DM). To measure beam transverse emittance at the Low Energy Beam Transport section, two Allison scanners are installed behind the DM for the X and Y directions. It consist of a servo motor for driving, a Faraday cup for current measurement, deflection plates, and electronic device. The measurable range of beam angle in of the Allison scanner is determined by the structure of the deflection plate and designed based on mathematical calculations. Experimental Physics and Industrial Control System (EPICS) is adopted to integrate and control a variety of devices. To control the complex measurement sequence of the Allison scanner, an EPICS sequencer module was used. Normalized emittance is calculated by python code with Pyepics module using phase space distribution data. In this paper, we present the detailed design of the Allison scanner, the configuration of the control system, and the experimental results using an Ar9+ 30 μA beam.

Using FPGA-Based AMC Carrier Boards for FMC to Implement Intelligent Data Acquisition Applications in MTCA Systems Using OpenCL

The Micro Telecommunications Computing Architecture (MTCA) standard is widely used in developing advanced data acquisition and processing solutions in the big physics community. The number of applications implemented using commercial Advanced Mezzanine Cards (AMC) using AMD-Xilinx and Intel® Field Programmable Gate Array (FPGA) systems on chips is growing due to the flexibility and scalability of these reconfigurable hardware devices and their suitability to implement intelligent applications using artificial intelligence and machine learning techniques. The paper presents the specific design methodologies for hardware acceleration proposed by both FPGA manufacturers. Comparative results are obtained from two different software/hardware setups using two different AMCs, one based on Intel® FPGA Arria 10 and another based on Xilinx ZynqMP. The paper illustrates the process of how to modify the board support package, required by the hardware acceleration methodology, to implement the JESD204B and Low-Voltage Differential Signaling (LVDS) interfaces with the FPGA Mezzanine Card (FMC) modules containing the ADCs, to prepare the AMC cards to implement such kind of applications. The data acquisition and processing implementation inside these reference designs, with both languages OpenCL and High-Level Synthesis (HLS), is described. An important feature, needed for many applications in the big physics field, is the interface with the Experimental Physics and Industrial Control System (EPICS) software framework using the ITER Nominal Device Support framework, which is briefly described.

RACS2: a framework of a remote autonomous control system for telescope observation and its application

With the increasing demand for astronomical observations, telescope systems are becoming increasingly complex. Thus, the observatory control software needs to be more intelligent. It has to control each instrument inside the observatory, finish the observational tasks autonomously, and report the information to users if needed. We developed a distributed autonomous observatory control framework named the Remote Autonomous Control System 2nd (RACS2) to meet these requirements. Rich features are integrated into the RACS2 framework. The RACS2 is a modular framework, in which each device control software and system services are implemented as different components. Furthermore, the RACS2 framework assimilates new techniques, such as a lightweight message and serialization mechanism. RACS2 also has good compatibility with other frameworks or ecosystems such as Python and the EPICS (Experimental Physics and Industrial Control System). The RACS2 framework can communicate with EPICS-based and Python-based software. With the help of these features, key system components like executor, scheduler are developed. The executor component can support sophisticated tasks. Autonomous observation can be achieved by the scheduler component. A set of web-based graphical user interface (GUI) is designed to help control and manage the framework remotely. Based on the RACS2 framework, we have implemented the Dome A Twins (DATs) telescope’s observation system and the space object observation system. The systems have been operated for more than 1 year. The RACS2 framework also has been used in our other projects like camera control system of Wide Field Survey Telescope (WFST) and its observatory control system, and the design can be a useful reference for the development of other frameworks.

Optimization of Automatic Control and Measurement for the HEPS Large-Scale High-Power RF Conditioning Test

High power radio frequency (RF) conditioning is a key step for the RF components to gain full performance. In the construction of high energy photon source (HEPS), upgrading Beijing Electron-Positron Collider (BEPCII), preresearch of circular electron positron collider (CEPC), and other projects at Institute of High Energy Physics (IHEP), there will be a lot of RF conditioning tasks within a very tight schedule. To improve the conditioning efficiency, an optimized automatic control has been developed. The automatic control system is developed based on the Experimental Physics and Industrial Control System (EPICS). The control hardware platform adopts a combination of the Micro Telecom Computing Architecture (MTCA) based low-level control and programmable logic controller (PLC) interlocking unit, which integrates a variety of measurements to ensure safe and reliable unattended operations during high-power (up to 160 MW) and high gradient (up to 33 MV/m) testing. The finite state transfer based on multiple event-triggered interrupt processes is used to improve conditioning efficiency. Taking the conditioning of the HEPS 3-m-long acceleration structure as an example, the breakdown rate (BDR) at high power is less than one out of 180 000 pulses. The time consumed for each accelerating structure is reduced by a factor of nearly 2/3. Experiments show that the system realizes the unattended operation of whole process, and improves conditioning efficiency.

Design of a beam automatic recovery system for the CAFe

The Chinese Accelerator Facility for Super-heavy Elements (CAFe) was designed by the Linear Accelerator Center, Institute of Modern Physics, Chinese Academy of Sciences (IMP), and is currently in regular operation. As a national science facility, it plays a significant role in the development of accelerator technology in China. This paper presents a detailed description of a new beam automatic recovery control system that was proposed, designed, and implemented by our team for CAFe. The entire project, including hardware and software construction, was completed in January 2021. The hardware consists of a field-programmable gate array (FPGA) based master–slave control board, while the software implementation was carried out using a combination of Python and Experimental Physics and Industrial Control System (EPICS). The system can effectively and reliably perform required actions based on different beam situations, and also enables automatic machine protection.

An integrated system for user-friendly X-ray intensity attenuation in a wide energy range

For undulator hard X-ray beamlines of a wide energy range, the beam intensity control is often needed to regulate the photon flux impinging on delicate detectors. Despite the capability of state-of-the-art X-ray pixel detectors being greatly advanced recently, the frontier undulator beamlines in synchrotron facilities often carry outstanding photon fluxes that are sometimes too high for certain measurements. Here, we report a developed protocol that allows intensity attenuation of an X-ray beam in the 4-23 keV energy range with flexible attenuation factors; a prototype is installed and tested on the 13A biological small-angle X-ray scattering beamline of the 3 GeV Taiwan Photon Source (TPS) of the National Synchrotron Radiation Research Center, Hsinchu, Taiwan. The intensity attenuation system is modified from a commercially available pneumatically actuated, vacuum-type precision X-ray attenuator of ADC ABS-300; the system provides beam attenuation factors covering 8 orders of intensity attenuation for an X-ray beam in 4-23 keV. This was achieved with selected combinations of 10 sets of metal foils comprising different thicknesses of Al, Ti, Cu, and Ta foils. A user-friendly protocol is established to automatically compare a subscribed attenuation factor with all the possible attenuation factors from the 1024 combinations of the 10 sets of foils in the X-ray energy used, and determine a set of the metal foils having a best-matched attenuation factor. Calculation of beam intensity attenuations with the selected foils is coded with Python and integrated into the Experimental Physics and Industrial Control System (EPICS). The input of an attenuation factor is done through a graphical display of the attenuator system based on the Control System Studio (CSS). The developed X-ray beam attenuation system provides a convenient and intuitive beam intensity control and has the potential to be adopted in future beamlines.

Design and implementation of superconducting cavity coupler RF conditioning platform control system for CSNS-II

According to the upgrade plan of CSNS-II (China Spallation Neutron Source Phase II), the beam power on target of CSNS needs to be increased to 400 kW in the future. In order to achieve this goal, a superconducting acceleration section will be added behind the LINAC (Linear Accelerator) section of CSNS-I. The superconducting acceleration section includes two superconducting cavity types operating at 324 MHz and 648 MHz. At present, the 324 MHz superconducting cavity couplers have been produced. In order to perform the RF conditioning and test the power transmission capability of the coupler, we designed and built a corresponding automatic RF conditioning control platform in the gallery of CSNS LINAC. The control system hardware is based on Micro TCA (Micro Telecommunications Computing Architecture, MTCA) LLRF (low-level radio frequency) control system, and the software development is based on EPICS (Experimental Physics and Industrial Control System). PLC (Programmable Logic Controller) based data acquisition and monitoring slow protection system, in-house developed interlocking fast protection system and some general equipment constitute the main hardware facilities, while EPICS IOC (input and output controller) and CSS (Control System Studio) OPI (Operator Interface) constitute a main pillar of control software. The control logic of the RF conditioning program mainly uses the vacuum pressure readings collected from the coupler as the judgment standard, and controls the power autonomously according to the real-time vacuum data, which can largely avoid human misoperation and greatly reduce the operator’s workload. At present, the system has started to run, and the actual work results show that its hardware and software performance are excellent, which ensures the safe and smooth progress of the RF condition process. In this article, we will first introduce the hardware architecture of the entire system, secondly introduce the software architecture and control logic of RF conditioning, and finally give the actual working results of the control system.

Design of the vacuum-centralized control system for the space plasma environment research facility based on the Experimental Physics and Industrial Control System

The Space Plasma Environment Research Facility (SPERF) is a ground-simulation facility, which is under construction, for studying space plasma. It includes a terrestrial space plasma environment simulation system (T-S system) and near-space plasma environment simulation system (N-S system). Plasma experiments performed on the SPERF require the functional cooperation of each subsystem. Therefore, the Experimental Physics and Industrial Control System (EPICS) was selected as the middleware in the engineering phase. Currently, the architecture of a vacuum-centralized control system is almost complete, and it is in the process of debugging. The application of EPICS in the SPERF vacuum-centralized control system has laid a structural foundation for the integration of other control systems and provides a test bed. In this study, we describe the implementation of EPICS for the SPERF vacuum-centralized control system, a procedure from hardware drivers realizing operation panels.

The development of the alarm system for HLS-II

Hefei Light Source II (HLS-II) is a vacuum ultraviolet synchrotron light source. The control system of HLS-II is a distributed system based on the experimental physics and industrial control system (EPICS). The alarm system of HLS-II is responsible for monitoring the alarm state of the facility and distributing the alarm message in time. It facilitates the operator to troubleshoot problem efficiently, so as to improve the availability of HLS-II. Phoebus/Alarms (Alarms) is the latest alarm software released in EPICS community. Based on Alarms, the alarm system of HLS-II is designed, developed and deployed. The alarm distribution strategy is designed from the perspective of the HLS-II operation mode, alarm severity and alarm representative to overcome alarm floods. The 3 ways to distribute the alarm message are added to the HLS-II alarm system, which include WeChat, SMS and web-based GUI. In order to configure alarm options efficiently and conveniently, an alarm configuration management tool is developed based on the MySQL database and Browser/Server architecture. The alarm system of HLS-II has been deployed since November 2021. The result indicates that the alarm system is effective and convenient to operate.

Archiving System for EAST PF Power Supply

The poloidal field (PF) power supply is an important subsystem of the Experimental Advanced Superconducting Tokamak (EAST). The monitor system of the PF power supply is based on the Experimental Physics and Industrial Control System (EPICS), using Control System Studio (CSS) as the human-machine interface. Archive, which is for data archiving, is a plugin of CSS. This paper creates an archiving system, including archive engine, client, and relational database (RDB). The process variables that need to be archived are configured so that they can be stored to RDB when changed. Real-time archiving for all input signals is realized, and history data can be browsed at any time through CSS. The archiving system provides a data basis for analyzing the EAST PF power supply, applied to the EAST experiment for more than 5 years, showing stable performance.

Mu2e DAQ and slow control systems

The Mu2e experiment at the Fermilab Muon Campus will search for the coherent neutrinoless conversion of a muon into an electron in the field of an aluminum nucleus with a sensitivity improvement by a factor of 10,000 over existing limits. The Mu2e Trigger and Data Acquisition System (TDAQ) uses otsdaq as the online Data Acquisition System (DAQ) solution. Developed at Fermilab, otsdaq integrates both the artdaq DAQ and the art analysis frameworks for event transfer, filtering, and processing. otsdaq is an online DAQ software suite with a focus on flexibility and scalability and provides a multiuser, web-based, interface accessible through a web browser. The data stream from the detector subsystems is read by a software filter algorithm that selects events which are combined with the data flux coming from a Cosmic Ray Veto System. The Detector Control System (DCS) has been developed using the Experimental Physics and Industrial Control System (EPICS) open source platform for monitoring, controlling, alarming, and archiving. The DCS System has been integrated into otsdaq. A prototype of the TDAQ and the DCS systems has been built at Fermilab’s Feynman Computing Center. In this paper, we report on the progress of the integration of this prototype in the online otsdaq software.

Design and development of the S-band high power test stand for multi-purpose applications at IHEP

A multipurpose S-band high-power test stand (HPTS) developed at the Institute of High Energy Physics (IHEP) of China is routinely used for radio-frequency (RF) conditioning of couplers and resonant structures, as well as other high-power experiments in the S-band frequency regime. The HPTS with a peak power of 230 MW was developed to meet requirements of various applications with multiple frequencies (2856 MHz/2998 MHz) and power levels (45 MW/50 MW/65 MW/80 MW) for different accelerator projects at the IHEP, e.g. the High Energy Photon Source (HEPS), Beijing Electron Positron Collider (BEPCII), Circular Electron Positron Collider (CEPC). This paper describes the design and implementation of the system in detail. The highlight of the HPTS is the impedance-matched design to accommodate different impedances, allowing a single pulse modulator to supply different types of klystron loads. The control system, developed under the Experimental Physics and Industrial Control System (EPICS), adopts a combination of Micro Telecommunications Computing Architecture (MTCA) based low-level RF system (LLRF) and programmable logic controller (PLC) based interlock unit controllers, and enables a real-time data acquisition and visualization. To ensure a high reliability and high-gradient RF power conditioning, the interlock unit integrates various protection features, like the short circuit load, high standing wave ratio, low vacuum, arcing detector, and abnormal dark current. It is worth mentioning that the entire conditioning procedure can be performed unattended automatically controlled. The test stand has been operated stably for more than 7,000 hours for many rounds of high-power RF conditioning with different power/frequency requirements, which indicates that the HPTS can provide a stable, reliable, and automatic high-power testing for the development of S-band related devices.