A Wire-Based Methodology to Analyse the Nanometric Resolution of an RF Cavity BPM

Resonant Cavity Beam Position Monitors (RF-BPMs) are diagnostic instruments capable of achieving beam position resolutions down to the nanometre scale. To date, their nanometric resolution capabilities have been predicted by simulation and verified through beam-based measurements with particle beams. In the frame of the PACMAN project at CERN, an innovative methodology has been developed to directly observe signal variations corresponding to nanometric displacements of the BPM cavity with respect to a conductive stretched wire. The cavity BPM of this R&D study operates at the TM110 dipole mode frequency of 15GHz. The concepts and details of the RF stretched wire BPM testbench to achieve the best resolution results are presented, along with the required control hardware and software

Millikelvin measurements of permittivity and loss tangent of lithium niobate

Lithium Niobate is an electro-optic material with many applications in microwave signal processing, communication, quantum sensing, and quantum computing. In this letter, we present findings on evaluating the complex electromagnetic permittivity of lithium niobate at millikelvin temperatures. Measurements are carried out using a resonant-type method with a superconducting radio-frequency (SRF) cavity operating at 7 GHz and designed to characterize anisotropic dielectrics. The relative permittivity tensor and loss tangent are measured at 50 mK with unprecedented accuracy.Comment: 5 pages, 4 figure

Quantum Simulation for High Energy Physics

It is for the first time that Quantum Simulation for High Energy Physics (HEP) is studied in the U.S. decadal particle-physics community planning, and in fact until recently, this was not considered a mainstream topic in the community. This fact speaks of a remarkable rate of growth of this subfield over the past few years, stimulated by the impressive advancements in Quantum Information Sciences (QIS) and associated technologies over the past decade, and the significant investment in this area by the government and private sectors in the U.S. and other countries. High-energy physicists have quickly identified problems of importance to our understanding of nature at the most fundamental level, from tiniest distances to cosmological extents, that are intractable with classical computers but may benefit from quantum advantage. They have initiated, and continue to carry out, a vigorous program in theory, algorithm, and hardware co-design for simulations of relevance to the HEP mission. This community whitepaper is an attempt to bring this exciting and yet challenging area of research to the spotlight, and to elaborate on what the promises, requirements, challenges, and potential solutions are over the next decade and beyond.Comment: This is a whitepaper prepared for the topical groups CompF6 (Quantum computing), TF05 (Lattice Gauge Theory), and TF10 (Quantum Information Science) within the Computational Frontier and Theory Frontier of the U.S. Community Study on the Future of Particle Physics (Snowmass 2021). 103 pages and 1 figur

Charged Particle Tracking in Real-Time Using a Full-Mesh Data Delivery Architecture and Associative Memory Techniques

We present a flexible and scalable approach to address the challenges of charged particle track reconstruction in real-time event filters (Level-1 triggers) in collider physics experiments. The method described here is based on a full-mesh architecture for data distribution and relies on the Associative Memory approach to implement a pattern recognition algorithm that quickly identifies and organizes hits associated to trajectories of particles originating from particle collisions. We describe a successful implementation of a demonstration system composed of several innovative hardware and algorithmic elements. The implementation of a full-size system relies on the assumption that an Associative Memory device with the sufficient pattern density becomes available in the future, either through a dedicated ASIC or a modern FPGA. We demonstrate excellent performance in terms of track reconstruction efficiency, purity, momentum resolution, and processing time measured with data from a simulated LHC-like tracking detector

Radio Frequency Characterization and Alignment to the Nanometer Scale of a Beam Position Monitor for Particle Accelerators

The Compact LInear Collider (CLIC) study at CERN requires low emittance beam transportation and preservation, thus a precise control of the transverse beam orbit along two separate 20 km-long linacs in the micrometric regime is crucial to achieve high luminosity collisions. A series of resonant cavity Beam Position Monitors (BPMs) is located along the beam line, each near a focusing beam quadrupole. While the BPMs are used to precisely monitor the beam trajectory along the evacuated beam pipe, the quadrupole magnets are essential to focus the particle beam. The two devices are attached in such a way that beam drifts from the magnetic center of the quadrupole will be monitored by the BPM and consequently controlled to avoid emittance blow up. The PACMAN project aims to pre-align the BPM and the Main Beam Quadrupole (MBQ) on a common support in a laboratory environment with micrometric accuracy, this is a mandatory first step to meet the CLIC luminosity and emittance specifications. A dedicated standalone test bench for observing mechanical and electromagnetic misalignments was designed, including nano-positioning stages for beam trajectory adjustments. The electromagnetic offset between the two devices is characterized through stretched and vibrating wire measurements techniques. This doctoral dissertation focuses on the study and the analysis of the cavity BPM designed for the CLIC Test Facility (CTF3). Measurements, RF characterization and final fiducialization of the BPM-MBQ electromagnetic offset are treated with details. Initial studies through EM simulations of the cavity BPM are covered, along with a discussion on the implementation of state-of-the-art RF measurements methods. The RF stretched-wire characterization is implemented on both the Final PACMAN Alignment Bench (FPAB) and the single BPM. The presented experimental results prove the feasibility of the innovative alignment methodology established by the PACMAN team, locating the electromagnetic displacement between the quadrupole and the attached BPM in a micrometric range. As a supplementary challenge, the verification of the nanometric resolution of the position cavity BPM was undertaken through an innovative, wire-based, approach

Digital Signal Processing and Generation for a DC Current Transformer for Particle Accelerators

Lo scopo della tesi è quello di realizzare un sistema di misura completo della corrente indotta dal beam di particelle in un acceleratore, tale strumento è chiamato DCCT (Direct Current Current Transformer). In particolare è stata curata la parte relativa al signal processing

High-fidelity quantum transduction with long coherence time superconducting resonators

We propose a novel quantum transduction hybrid system based on the coupling of long-coherence time superconducting cavities with electro-optic resonators to achieve high-efficiency and high-fidelity in quantum communication protocols and quantum sensing. \copyright 2022 The Author(s)Comment: 2 pages, 3 figure

Study of the Electrical Center of a Resonant Cavity Beam Position Monitor (RF-BPM) and Its Integration with the Main Beam Quadrupole for Alignment Purposes

To achieve the luminosity goals in a next generation linear collider, acceleration and preservation of ultra-low emittance particle beams is mission critical and requires a precise alignment between the main accelerator components. PACMAN is an innovative doctoral training program, hosted by CERN, with the goal of developing high accuracy metrology and alignment methods and tools to integrate those components in a standalone, automatic test bench. The method will be validated on CLIC components, a proposed Compact Linear Collider currently studied at CERN. The alignment between the electrical center of the Beam Position Monitor (BPM) and the magnetic center of the associated Main Beam Quadrupole (MBQ) is of particular importance to minimize the emittance blow-up, and therefore in the focus of the PACMAN project. On a first stage the two components have been independently characterized on separated test benches by stretched and vibrating wire techniques. Preliminary conclusions are presented in this paper, with emphasis on the characterization of the electrical center of the BPM