Related papers: Analysis and Synthesis of the SNS Superconducting …
Convolution neural networks have achieved remarkable performance in many tasks of computing vision. However, CNN tends to bias to low frequency components. They prioritize capturing low frequency patterns which lead them fail when suffering…
We present a design and implementation of frequency-tunable superconducting resonator. The resonance frequency tunability is achieved by flux-coupling a superconducting LC-loop to a current-biased feedline; the resulting screening current…
Using the China Spallation Neutron Source (CSNS) linac as the injector, a 500 MeV proton synchrotron is proposed for multidisciplinary application, such as biology, material and proton therapy. The synchrotron will deliver proton beam with…
In niobium superconducting radio frequency (SRF) accelerating cavities a decrease of the quality factor at lower fields - a so called \emph{low field Q slope or LFQS} - has been a long-standing unexplained effect. By extending the high $Q$…
In recent years, spiking neural networks (SNNs) have been used in reinforcement learning (RL) due to their low power consumption and event-driven features. However, spiking reinforcement learning (SRL), which suffers from fixed coding…
European Spallation Source will be the brightest neutron source in the world. It is being built in Lund, Sweden. Over 120 superconducting cavities will be installed in the facility, each regulated by an individual LLRF control system. To…
This document describes a new package to compute high performance simulations of a module of superconducting accelerating cavities from the LLRF controller perspective. The reason to make a dedicated C++/Python package is to simulate all…
CSNS/RCS accelerates a high-intensity proton beam from 80 MeV to 1.6 GeV. Since the beam current and beam power is high, the beam loading is a severe problem for the stability of the circulating beam in the RCS. To study the beam loading…
The thermionic gridded gun is described which generates short electron bunches for further acceleration in a Nb3Sn conduction cooled SRF linac. The gun is built into the first cavity of the 250 keV injector [1] for the 20 kW, 10 MeV, 1.3…
Quantum sensing and computation can be realized with superconducting microwave circuits. Qubits are engineered quantum systems of capacitors and inductors with non-linear Josephson junctions. They operate in the single-excitation quantum…
At the end of the Large Hadron Collider's Run 2, CERN's Proton Injector Linac 2, commissioned in 1978, delivered its final beam in December 2018. For Run 3, from March 2021, a new H$^{-}$ will take over the role: Linac4. The machine has…
Material disorders are one of the major sources of noise and loss in solid-state quantum devices, whose behaviors are often modeled as two-level systems (TLSs) formed by charge tunneling between neighboring sites. However, the role of their…
In the framework of the Compact Light XLS project, a short ultra-high gradient linearizer working on the third harmonic of the main LINAC frequency is requested. Increasing gradients and reducing dimensions are requirements for XLS and all…
Reinforcement learning (RL) has shown great potential in training agile and adaptable controllers for legged robots, enabling them to learn complex locomotion behaviors directly from experience. However, policies trained in simulation often…
Although the main loss channel of planar microwave superconducting resonators has been identified to be related to an external coupling to a two-level system (TLS) bath, the behavior of such a cavity in the presence of an off-resonant pump…
This paper addresses the robust ${\cal H}_2$ synthesis problem for linear fractional transformation (LFT) systems subject to structured uncertainty (parameter) and white-noise disturbances. By introducing an intermediate matrix variable, we…
The main `bottleneck' limiting the beam power in circular machines is caused by space charge effects that produce beam instabilities. To increase maximally the beam power of a `proton driver', it is proposed to build a facility consisting…
This paper presents a robust control synthesis and analysis framework for nonlinear systems with uncertain initial conditions. First, a deep learning-based lifting approach is proposed to approximate nonlinear dynamical systems with linear…
The Self-Excited Loop (SEL) architecture, used in some continuous-wave (CW) superconducting linacs, relies on a positive feedback mechanism that requires carefully defined operating limits to ensure stable operation. These limits are…
Lipschitz continuous sliding-mode controllers (LCSMC) are developed as the integral of discontinuous SMC, producing control signals of finite slope. Nevertheless, LCSMC still generate chattering in the presence of fast parasitic dynamics.…