Optimizing RF Accelerator Klystron Modulator Design at the (RF Power) System-Level
The 2016 IPMHVC will be holding a mini-workshop on the afternoon of Thursday, July 7. This workshop will take place in the Pacific Heights room on the second floor of the Palace hotel. The workshop is free for registered attendees of the IPMHVC and no extra registration is required. The workshop is co-chaired by Dr. Davide Aguglia (CERN, Davide.Aguglia@cern.ch) and Dr. Craig Burkhart (SLAC,burkhart@slac.stanford.edu). As further details become available, they will be posted here. In the mean time, questions can be directed to either Dr. Burkhart or Dr. Aguglia.
Outline and objectives
When developing small research or industrial accelerator facilities employing Radio Frequency (RF) power sources, the design cost can be considerable compared to the total project cost. Therefore limiting the design effort to a meticulous selection of standard off the shelf products may be a cost effective solution. In contrast, in large facilities where the RF power system has a significant impact on the global technical performance and cost, the design of the electrical to RF power conversion system should be addressed differently. When industrial standards do not exist, or the project scale is sufficient to develop “project standards,” it becomes important to adopt an organized and integrated design optimization process. For instance if both the klystron and modulator are new designs, the interface voltage becomes a free parameter. However, there are typically design team, and other organizational boundaries, at the technology interface between the RF and power converter engineers that can impede integrated optimization of these sub-systems.
The workshop aims at:
- Analyzing these interfaces, the design constraints that they introduce, impediments to integrated design optimization, and strategies to transcend these limitations;
- Introducing optimization methods suitable for integrated design;
- Share experiences and create links between people from different organizations and countries who are facing similar design challenges.
The workshop will begin with talks on the optimization of the CLIC RF power system and swarm optimization. This will be followed by a working-group discussion, analyzing system interfaces for a strawman accelerator RF power system and discuss participant experience; design constraints, impediments to integrated design optimization, and strategies to transcend these limitations.
Workshop Schedule
Thursday 7th July 15h30 – 17-30
15h30 – 16h00 (20’+10’) - Workshop talk 1
Using an Integrated Design Approach for the Compact Linear Collider (CLIC) Klystron Modulators
Presenter – D. Aguglia, CERN
Abstract: The Compact Linear Collider is a 50 km long linear accelerator aiming at colliding electrons and positrons in the TeV range for fundamental physics research. Due to the high technical and financial impacts, an integrated design optimization, which balances total cost versus global performance, is required for the RF power system; encompassing civil engineering impacts, electrical distribution, modulator, and klystron. Design compromises such as modulator output voltage regulation versus low level RF control capabilities or global electrical efficiency versus AC distribution voltage are presented to highlight the importance and needs for an integrated design optimization. We present the optimized CLIC RF power system (electrical distribution and modulators) parameters and the system sensitivity to parametric variations.
16h00 – 16h30 (20’+10’) - Workshop talk 2
Particle Swarm Optimization Techniques for Pulsed Power Systems
Presenter – A. Jensen, SLAC
Abstract: Finding an optimal solution for a power system design becomes difficult when multiple components, several simulation tools, and often-competing goals are involved. A common pitfall is to fall into local optimization minima while bypassing a more advantageous global optimum. These challenges are not unique to accelerator power systems. Optimization algorithms implemented in fields as diverse as internet traffic management, efficient building design, and handwriting analysis can be applied. We discuss implementation of a class of computational intelligence algorithms, Particle Swarm Optimization, as applied to power system optimization.
16h30 – 17h30 - Workshop discussion
Optimizing Power Converter Design at the (RF Power) System-Level
Moderators: Davide and Craig
Secretary: TBD (notes, record)
Abstract: Power converter designs are optimized (performance, cost) to constraints defined by interfacing systems; e.g. local power grid (available power, voltage and cost) and the RF source (perveance, output power, input voltage, and pulse duration). Often this leads to both inefficient converters and RF power systems, due to challenges presented by the interface constraints. The discussion session will address the optimization process for a strawman accelerator design; examining the interface constraints and their impact on the klystron modulator design. The discussion will draw on the experience of workshop participants; what typically defines your design constraints, what are the impacts of these constraints, and how might these limitations be transcended. The ultimate goal of this effort is to empower designers to impact their system interface constraints to achieve designs that enhance the performance of the power converter and the overall system they support.