Resumen de Linear IFMIF prototype accelerator (LIPAc) control system: design and development
Julio Calvo Pinto
Distributed real time control systems in scientific instruments, such as particle accelerators or telescopes, have emerged as a solution to control multiple interconnected devices, which required constant attention and observation, along with a complete integration of each of its parts. This enhancement is provided by the intense technological development that control devices have suffered in recent years. With respect to the control software, libraries and applications have also emerged in recent times. These sets of tools have been developed collaboratively in various laboratories and research centers worldwide. Experimental Physics and Industrial Control System (EPICS), a set of open source tools capable of controlling most of the devices necessary to operate a particle accelerator, can be pointed as a prime example of this progress. This thesis presents the design and development of the EPICS based control system for Linear IFMIF1 Prototype Accelerator (LIPAc), which construction involves several countries and it is currently being carried out in Rokkasho, Japan. LIPAc comprises a succession of devices and systems that focus and accelerate deuteron beam to an energy of 9 MeV with a current of 125mA, developing a previously unobtainable power of 1.125MW for that given energy. Therefore, due to the spatial charge issues associated with those beam properties, the operational requirements of such magnitudes make a complex control system but fundamental to proper operation of the prototype accelerator. LIPAc should serve as a key to demonstrate the feasibility in the construction of the IFMIF, an indispensable tool on the way to the conquest of nuclear fusion as an alternative energy source, capable of evaluating possible materials that can be used in the first nuclear fusion reactor, to be erected in the near future. The paradigm of distributed control systems has been established within the engineering community control as a set of software and hardware technologies that provide the necessary elements for seamless integration of system components, in our case, a particle accelerator. This work presents the development of a distributed control system based on EPICS, using architectures, tools and applications that present the operation of the device as a robust set of data and variables, both accessible and understandable by engineers and operators. The first part of this document is dedicated to review the need for nuclear fusion, framing the work presented as one of the previous steps to achieve this complex milestone. Next, a review in control systems architectures for particle accelerators is exposed. Then, it is provided an overview of current control systems with special emphasis on installations whose control is based on EPICS. Due to the large extension of the existing works, this section is not intended to be a comprehensive review, but rather a framework for establishing the context of this work and a way to highlight the most outstanding ones. The second part provides a description of the proposal made, which involves the design and development of a distributed control system based on EPICS. Among all kinds of control architectures, the distributed multilayer has been chosen, wherein the control system is presented as a set of hierarchical layers ranging from the resource layer, closest to the devices, until the presentation layer, closest to the operator, through the application layer. The main contribution of this proposal is the use of technology-based distributed control system over an EPICS framework, giving specific solutions to each part of the accelerator but maintaining the multi-tiered architecture. Specifically, it proposes several solutions based on the same technology software for different local control systems with the advantage of achieving a complete integration of the system and a complete understanding between all components, highlighting the development of the low level radiofrequency control system, one of the most delicate and important parts of the accelerator. Some elements of the developed system have been tested experimentally, first instance at Ciemat facilities, using the necessary devices to simulate input data. On the other hand, the radio frequency system and its control have been tested also at high energy.
