arXiv subjects

E. A. Nanni

Publications and source records attributed to E. A. Nanni.

10 recordsLinked to original sources

arXiv2026

Sustainability Assessment of Future Accelerators

The Large Particle Physics Laboratory Directors Group (LDG) established the Working Group (WG) on the Sustainability Assessment of Future Accelerators in 2024 with the mandate to develop guidelines and a list of key parameters for the assessment of the sustainability of future accelerators in particle physics. While focused on accelerator projects, much of the work will also be relevant to other present and upcoming research infrastructures. The development and continuous update of such a framework aim to enable a coherent communication amongst scientists and adequately convey the information to a broader set of stakeholders. This document outlines the key findings and recommendations of the LDG Sustainability WG and provides a summary of current best practices aimed at enabling sustainable accelerator-based research infrastructures. Not all sustainability topics are addressed at the same level. The assessment process is complex, largely under development and a homogeneous evaluation of all the aspects requires a strategy to be developed and implemented over time.

physics.acc-ph↗

arXiv2025

Next generation direct RF sampling LLRF control and monitoring system for linear accelerators

The low-level RF (LLRF) systems for linear accelerating structures are typically based on heterodyne architectures. The linear accelerators normally have many RF stations and multiple RF inputs and outputs for each station, so the complexity and size of the LLRF system grows rapidly when scaling up. To meet the design goals of being compact and affordable for future accelerators, or upgrading existing ones, we have developed and characterized the next generation LLRF (NG-LLRF) platform based on the RF system-on-chip (RFSoC) for S-band and C-band accelerating structures. The integrated RF data converters in RFSoC sample and generate the RF signals directly without any analogue mixing circuits, which significantly simplified the architecture compared with the conventional LLRF systems. We have performed high-power tests for the NG-LLRF with the S-band accelerating structure in the Next Linear Collider Test Accelerator (NLCTA) test facility at SLAC National Accelerator Laboratory and a C-band structure prototyped for Cool Cooper Collider (CCC). The NG-LLRF platform demonstrated pulse-to-pulse fluctuation levels considerably better than the requirements of the targeted applications and high precision and flexibility in generating and measuring the RF pulses. In this paper, the characterization results of the platform with different system architectures will be summarized and a selection of high-power test results of the NG-LLRF will be presented and analyzed.

physics.acc-ph↗

arXiv2025

Sustainability Assessment of Future Accelerators

The Large Particle Physics Laboratory Directors Group (LDG) established the Working Group on the Sustainability Assessment of Future Accelerators in 2024 with the mandate to develop guidelines and a list of key parameters for the assessment of the sustainability of future accelerators in particle physics. While focused on accelerator projects, much of the work will also be relevant to other current and future Research Infrastructures. The development and continuous update of such a framework aim to enable a coherent communication amongst scientists and adequately convey the information to a broader set of stakeholders. This document outlines the major findings and recommendations from the LDG Sustainability WG report - a summary of current best practices recommended to be adopted by new Research Infrastructures. The full report will be available in June 2025 at: https://ldg.web.cern.ch/working-groups/sustainability-assessment-of-accelerators. Not all of sustainability topics are addressed at the same level. The assessment process is complex, largely under development and a homogeneous evaluation of all the aspects deserves a strategy to be pursued over time.

hep-ex↗

arXiv2024

Direct RF Sampling based LLRF Control System for C-band Linear Accelerator

Low Level RF (LLRF) control systems of linear accelerators (LINACs) are typically implemented with heterodyne based architectures, which have complex analog RF mixers for up and down conversion. The Gen 3 Radio Frequency System-on-Chip (RFSoC) device from AMD Xilinx integrates data converters with maximum RF frequency of 6~GHz. This enables direct RF sampling of C-band LLRF signal typically operated at 5.712 GHz without any analogue mixers, which can significantly simplify the system architecture. The data converters sample RF signals in higher order Nyquist zones and then up or down convert digitally by the integrated data path in RFSoC. The closed-loop feedback control firmware implemented in FPGA integrated in RFSoC can process the base-band signal from the ADC data path and calculate the updated phase and amplitude to be up-mixed by the DAC data path. We have developed a C-band LLRF control RFSoC platform with direct RF sampling, which targets Cool Copper Collider (C3) and other C or S band LINAC research and development projects. In this paper, the architecture of the platform will be described. We have optimized the configuration of the data converter and characterized performance of them with RF pulses. The test results for some of the key performance parameters for the LLRF platform with our custom solid-state amplifier, such as phase and amplitude stability, will be discussed in this paper.

physics.acc-ph↗

arXiv2022

U.S. National Accelerator R\&D Program on Future Colliders

Future colliders are an essential component of a strategic vision for particle physics. Conceptual studies and technical developments for several exciting future collider options are underway internationally. In order to realize a future collider, a concerted accelerator R\&D program is required. The U.S. HEP accelerator R\&D program currently has no direct effort in collider-specific R\&D area. This shortcoming greatly compromises the U.S. leadership role in accelerator and particle physics. In this white paper, we propose a new national accelerator R\&D program on future colliders and outline the important characteristics of such a program.

physics.acc-ph↗

arXiv2019

Femtosecond compression dynamics and timing jitter suppression in a terahertz-driven electron bunch compressor

We present the first demonstration of THz-driven bunch compression and timing stabilization of a few-fC relativistic electron beam with kinetic energy of 2.5 MeV using quasi-single-cycle strong field THz radiation in a shorted parallel-plate structure. Compression by nearly a factor of 3 produced a 39 fs rms bunch length and a reduction in timing jitter by more than a factor of 2, to 31 fs rms, offering a significant improvement to beam performance for applications like ultrafast electron diffraction. This THz-driven technique provides a critical step towards unprecedented timing resolution in ultrafast sciences and other accelerator applications using femtosecond-scale electron beams.

physics.acc-ph↗

arXiv2019

Nanopatterned electron beams for temporal coherence and deterministic phase control of x-ray free-electron lasers

We demonstrate the ability to create electron beams with high-contrast, nanometer-scale density modulations as a first step toward developing full control of the phase fronts of an x-ray free-electron laser. The nanopatterned electron beams are produced by diffracting electrons through thin single-crystal silicon membranes that are lithographically patterned to different thicknesses. For transform-limited x-ray production the desired pattern is a series of regularly spaced lines (i.e. a grating) that generate uniformly spaced nanobunches of electrons, however nearly any pattern can be etched in the silicon, such as frequency-chirps or multiple patterns of different colors or line spacings. When these patterns are transferred from the spatial to the temporal dimension by accelerator electromagnetic optics they will control the phase fronts of coherent x-rays, giving unprecedented deterministic control over the phase of ultrashort x-ray pulses. In short, this method allows the time-structure for a fully coherent x-ray beam to be generated from a pattern written on a semiconductor wafer by lithography.

physics.acc-ph↗

arXiv2019

Theoretical and experimental electron diffraction intensity maps for single crystal silicon from an ultrafast source

Electron diffraction through a thin patterned silicon membrane can be used to create complex spatial modulations in electron distributions by varying the intensity of different reflections using parameters such as crystallographic orientation and wafer thickness, then selecting specific spots in the diffraction plane using apertures. The patterned electron beams can be used to control phase and amplitude of subsequent x-ray emission, enabling novel coherent x-ray methods. The electrons themselves can also be used for femtosecond time resolved diffraction and microscopy. As a first step toward patterned beams, we demonstrate experimentally and through simulation the ability to accurately predict and control diffraction spot intensities. We simulate MeV transmission electron diffraction patterns using the multislice method for various crystallographic orientations of a single crystal Si(100) membrane near beam normal. The resulting intensity maps of the Bragg reflections are compared to experimental results obtained at the Accelerator Structure Test Area Ultrafast Electron Diffraction (ASTA UED) facility at SLAC. Furthermore, the fraction of inelastic and elastic scattering of the initial charge is estimated along with the absorption of the membrane to determine the contrast that would be seen in a patterned version of the Si(100) membrane.

physics.acc-ph↗

arXiv2018

Terahertz-based attosecond metrology of relativistic electron beams

Photons, electrons, and their interplay are at the heart of photonic devices and modern instruments for ultrafast science [1-10]. Nowadays, electron beams of the highest intensity and brightness are created by photoemission with short laser pulses, and then accelerated and manipulated using GHz radiofrequency electromagnetic fields. The electron beams are utilized to directly map photoinduced dynamics with ultrafast electron scattering techniques, or further engaged for coherent radiation production at up to hard X-ray wavelengths [11-13]. The push towards improved timing precision between the electron beams and pump optical pulses though, has been stalled at the few tens of femtosecond level, due to technical challenges with synchronizing the high power rf fields with optical sources. Here, we demonstrate attosecond electron metrology using laser-generated single-cycle THz radiation, which is intrinsically phase locked to the optical drive pulses, to manipulate multi-MeV relativistic electron beams. Control and single-shot characterization of bright electron beams at this unprecedented level open up many new opportunities for atomic visualization.

physics.acc-ph↗

arXiv2014

Compact x-ray source based on burst-mode inverse Compton scattering at 100 kHz

A design for a compact x-ray light source (CXLS) with flux and brilliance orders of magnitude beyond existing laboratory scale sources is presented. The source is based on inverse Compton scattering of a high brightness electron bunch on a picosecond laser pulse. The accelerator is a novel high-efficiency standing-wave linac and RF photoinjector powered by a single ultrastable RF transmitter at x-band RF frequency. The high efficiency permits operation at repetition rates up to 1 kHz, which is further boosted to 100 kHz by operating with trains of 100 bunches of 100 pC charge, each separated by 5 ns. The entire accelerator is approximately 1 meter long and produces hard x-rays tunable over a wide range of photon energies. The colliding laser is a Yb:YAG solid-state amplifier producing 1030 nm, 100 mJ pulses at the same 1 kHz repetition rate as the accelerator. The laser pulse is frequency-doubled and stored for many passes in a ringdown cavity to match the linac pulse structure. At a photon energy of 12.4 keV, the predicted x-ray flux is $5 \times 10^{11}$ photons/second in a 5% bandwidth and the brilliance is $2 \times 10^{12}\mathrm{photons/(sec\ mm^2\ mrad^2\ 0.1\%)}$ in pulses with RMS pulse length of 490 fs. The nominal electron beam parameters are 18 MeV kinetic energy, 10 microamp average current, 0.5 microsecond macropulse length, resulting in average electron beam power of 180 W. Optimization of the x-ray output is presented along with design of the accelerator, laser, and x-ray optic components that are specific to the particular characteristics of the Compton scattered x-ray pulses.

physics.acc-ph↗