arXiv subjects

G. Stancari

Publications and source records attributed to G. Stancari.

At least 19 recordsLinked to original sources

arXiv2025

Proton Dynamics Scenarios in the Integrable Optics Test Accelerator (IOTA) at Fermilab

The Integrable Optics Test Accelerator (IOTA) at Fermilab provides a versatile platform for studying the interplay of space-charge, impedance, and non-linear optics in high-intensity hadron beams within synchrotrons and storage rings. This report examines the parameters and dynamics of 2.5 MeV proton beam operations in two configurations of the bare IOTA lattice (dipoles, quadrupoles, sextupoles, and rf cavity only): one for demonstrating Non-linear Integrable Optics with the Danilov-Nagaitsev magnet, and the other for use with electron cooling. We offer order-of-magnitude estimates of the transverse emittance growth rate as a function of beam intensity, highlighting contributions from residual gas scattering, intra-beam scattering, and space-charge effects. Under nominal conditions, the beam lifetime is projected to be less than 7 minutes at low intensity with the current vacuum quality, and fewer than 100,000 turns at high intensity due to strong space-charge effects. The calculations presented here will guide strategies to mitigate emittance growth and inform future IOTA experiments.

physics.acc-ph↗

arXiv2023

Experiments On Electron Cooling and Intense Space-charge at IOTA

The Integrable Optics Test Accelerator at Fermilab will explore beam dynamics in a ring with intense space-charge using 2.5 MeV proton beams with an incoherent tune shift approaching -0.5. We will use this machine to explore the interplay between electron cooling, intense space-charge, and coherent instabilities. In this contribution, we describe the machine setup including the design of the electron cooler and the lattice, list specific experiments and discuss the results of numerical simulations which include the effects of electron cooling and transverse space-charge forces.

physics.acc-ph↗

arXiv2023

Experimental Single Electron 4D Tracking in IOTA

This paper presents the results of the first experiments on 4D tracking of a single electron using a linear multi-anode photomultiplier tube. The reported technology makes it is possible to fully track a single electron in a storage ring, which requires tracking of amplitudes and phases for both, slow synchrotron and fast betatron oscillations. Complete tracking of a point-like object enabled the first direct measurements of single-particle dynamical properties, including dynamical invariants, amplitude-dependent oscillation frequencies, and chaotic behavior.

physics.acc-ph↗

arXiv2023

Thermionic Sources for Electron Cooling at IOTA

We are designing and fabricating two new thermionic sources of magnetized electrons for use in the electron lens project in the Integrable Optics Test Accelerator (IOTA) at Fermilab. These electron sources will be used for cooling 2.5 MeV protons. One source will be used to compensate for emittance growth due to Intra Beam Scattering in experiments with weak space-charge, while the other source will be used to research the interplay between electron cooling and intense space charge. In this paper we present the progress made so far and the upcoming steps for the thermionic electron sources.

physics.acc-ph↗

arXiv2023

Commissioning of the Low Energy Electron Gun Test Stand at the University of Chicago

We built a test stand for evaluating the performance of the thermionic electron sources for the electron lens project at the Integrable Optics Test Accelerator (IOTA) in Fermilab. The lens will be used to study nonlinear dynamics and electron cooling of 2.5 MeV protons with strong space charge. The test stand will validate the characteristics of the thermionic sources and the main parameters of the generated beams. In this paper we present the results of the commissioning of the UChicago test stand and validation of the hollow beam source.

physics.acc-ph↗

arXiv2023

Improved Measurements of Nonlinear Integrable Optics Invariants at IOTA

Nonlinear integrable optics (NIO) are a promising novel approach at improving the stability of high intensity beams. Implementations of NIO based on specialized magnetic elements are being tested at the Integrable Optics Test Accelerator (IOTA) at Fermilab. One method of verifying proper implementation of these solutions is by measuring the analytic invariants predicted by theory. The initial measurements of nonlinear invariants were performed during IOTA run in 2019/20, however the covid-19 pandemic prevented the full-scale experimental program from being completed. Several important improvements were implemented in IOTA for the 2022/23 run, including the operation at higher beam energy of 150 MeV, improved optics control, and chromaticity correction. This report presents the results of improved measurements of nonlinear invariants.

physics.acc-ph↗

arXiv2022

Electron Cooling Experiment for Proton Beams with Intense Space-charge in IOTA

Electron cooling as a method of creating intense ion beams has a practical upper limit when it comes to the peak phase space density of ion beams which can be achieved in practice. We describe a new experiment to study electron cooling of 2.5 MeV protons at the intensity limit using the Integrable Optics Test Accelerator (IOTA), which is a storage ring dedicated to beam physics research at Fermilab. This system will enable the study of magnetized electron cooling of a proton beam with transverse incoherent tune shifts approaching -0.5 due to the presence of intense space-charge forces. We present an overview of the hardware design, simulations and specific experiments planned for this project.

physics.acc-ph↗

arXiv2022

Thermionic Sources For Electron Cooling At IOTA

We are designing and fabricating two new thermionic sources of magnetized electrons for use in the electron lens project at the Integrable Optics Test Accelerator (IOTA) at Fermilab. These electron sources will be used for cooling of 2.5 MeV protons in the presence of intense space-charge. Furthermore, we are constructing an electron source test stand at the University of Chicago which will validate the electrical, thermal, and vacuum characteristics of thermionic sources. In this paper we present the progress made so far and the upcoming steps for the thermionic electron sources for electron cooling and the test stand.

physics.acc-ph↗

arXiv2022

Symplectic Particle Tracking in a Thick Nonlinear McMillan Lens for the Fermilab Integrable Optics Test Accelerator (IOTA)

The McMillan system is a novel method to increase the tune spread of a beam without decreasing its dynamic aperture due to the systems integrability. While the ideal system is based on an infinitely thin kick, the physical design requires a thick electron lens, including a solenoid. Particle transport through the lens is difficult to simulate due to the nature of the force on the circulating beam. This paper demonstrates accurate simulation of a thick McMillan lens in a solenoid using symplectic integrators derived from Yoshidas method.

physics.acc-ph↗

arXiv2022

Experimental demonstration of OSC at IOTA: IOTA Run #3 Report

Optical Stochastic Cooling (OSC) is an optical-bandwidth extension of Stochastic Cooling that could advance the state-of-the-art cooling rate in beam cooling by three to four orders of magnitude [1-3]. The concept of OSC was first suggested in the early 1990s by Zolotorev, Zholents and Mikhailichenko, and replaced the microwave hardware of SC with optical analogs, such as wigglers and optical amplifiers. A number of variations on the original OSC concept have been proposed, and while a variety of proof-of-principle demonstrations and operational uses have been considered, the concept was not experimentally demonstrated up to now [4-9]. An OSC R&D program has been underway at IOTA for the past several years [4]. Run #3 of the IOTA ring, which began in Nov. 2020 and concluded in Aug. 2021, was focused on the worlds first experimental demonstration of OSC. The experimental program was successful in demonstrating and characterizing the OSC physics with the major outcomes including strong cooling in one, two and three dimensions, validation of the theoretical models of OSC and the demonstration of OSC with a single electron. This report briefly describes the activities and major milestones of the OSC program during Run #3. Detailed descriptions of the OSC theory, conceptual design and hardware elements can be found in reference [4].

physics.acc-ph↗

arXiv2022

First Experimental Demonstration of Optical Stochastic Cooling

Particle accelerators and storage rings have been transformative instruments of discovery, and, for many applications, innovations in particle-beam cooling have been a principal driver of that success1. Beam cooling reduces the spread in particle positions and momenta, while keeping the number of particles constant, and combats diffusive effects, thereby enabling particle accumulation and the production and preservation of intense beams. In the case of particle colliders, cooling increases the likelihood of observing rare physics events. One of the most important conceptual and technological advances in this area was stochastic cooling (SC), which was instrumental in the discovery of the W and Z bosons at CERN and the top quark at Fermilab2-6. SC reduces the random motion of the beam particles through granular sampling and correction of the beams phase-space structure, thus bearing resemblance to a Maxwells demon. The extension of SC from the microwave regime up to optical frequencies and bandwidths has long been pursued as it could increase the achievable cooling rates by three to four orders of magnitude and provide a powerful new tool for future accelerators. First proposed nearly thirty years ago, Optical Stochastic Cooling (OSC) replaces the conventional microwave elements of SC with optical-frequency analogs and is, in principle, compatible with any species of charged-particle beam7,8. Here we describe the first experimental demonstration of OSC in a proof-of-principle experiment9 at the Fermi National Accelerator Laboratorys Integrable Optics Test Accelerator10.

physics.acc-ph↗

arXiv2022

Ion Coulomb Crystals in Storage Rings for Quantum Information Science

Quantum information science is a growing field that promises to take computing into a new age of higher performance and larger scale computing as well as being capable of solving problems classical computers are incapable of solving. The outstanding issue in practical quantum computing today is scaling up the system while maintaining interconnectivity of the qubits and low error rates in qubit operations to be able to implement error correction and fault-tolerant operations. Trapped ion qubits offer long coherence times that allow error correction. However, error correction algorithms require large numbers of qubits to work properly. We can potentially create many thousands (or more) of qubits with long coherence states in a storage ring. For example, a circular radio-frequency quadrupole, which acts as a large circular ion trap and could enable larger scale quantum computing. Such a Storage Ring Quantum Computer (SRQC) would be a scalable and fault tolerant quantum information system, composed of qubits with very long coherence lifetimes. With computing demands potentially outpacing the supply of high-performance systems, quantum computing could bring innovation and scientific advances to particle physics and other DOE supported programs. Increased support of R$\&$D in large scale ion trap quantum computers would allow the timely exploration of this exciting new scalable quantum computer. The R$\&$D program could start immediately at existing facilities and would include the design and construction of a prototype SRQC. We invite feedback from and collaboration with the particle physics and quantum information science communities.

physics.acc-ph↗

arXiv2022

Electron Cooling with Space-Charge Dominated Proton Beams at Iota

We describe a new electron cooler being developed for 2.5 MeV protons at the Integrable Optics Test Accelerator (IOTA), which is a highly re-configurable storage ring at Fermilab. This system would enable the study of magnetized electron cooling in the presence of intense space-charge with transverse tune shifts approaching -0.5 as well as highly nonlinear focusing optics in the IOTA ring. We present an overview of the design, simulations and hardware to be used for this project.

physics.acc-ph↗

arXiv2018

Commissioning and Operation of FAST Electron Linac at Fermilab

We report results of the beam commissioning and first operation of the 1.3 GHz superconducting RF electron linear accelerator at Fermilab Accelerator Science and Technology (FAST) facility. Construction of the linac was completed and the machine was commissioned with beam in 2017. The maximum total beam energy of about 300 MeV was achieved with the record energy gain of 250 MeV in the ILC-type SRF cryomodule. The photoinjector was tuned to produce trains of 200 pC bunches with a frequency of 3 MHz at a repetition rate of 1 Hz. This report describes the aspects of machine commissioning such as tuning of the SRF cryomodule and beam optics optimization. We also present highlights of an experimental program carried out parasitically during the two-month run, including studies of wake-fields, and advanced beam phase space manipulation.

physics.acc-ph↗

arXiv2018

Novel MCP-Based Electron Source Studies

Microchannel plates (MCPs) were recently proposed as novel type of cathodes for electron guns, suitable for applications in design of electron lenses. We report results of the first systematic study of microchannel plate based photomultiplier time response and maximum current density tests using different sources of light pulses. The Burle 85011-501 MCP-PMT is found to have good time response properties being capable of producing nanosecond long pulses with modest maximum current density and performance strongly dependent on magnetic field strength.

physics.acc-ph↗

arXiv2017

Collimation System

Chapter 5 in High-Luminosity Large Hadron Collider (HL-LHC) : Preliminary Design Report. The Large Hadron Collider (LHC) is one of the largest scientific instruments ever built. Since opening up a new energy frontier for exploration in 2010, it has gathered a global user community of about 7,000 scientists working in fundamental particle physics and the physics of hadronic matter at extreme temperature and density. To sustain and extend its discovery potential, the LHC will need a major upgrade in the 2020s. This will increase its luminosity (rate of collisions) by a factor of five beyond the original design value and the integrated luminosity (total collisions created) by a factor ten. The LHC is already a highly complex and exquisitely optimised machine so this upgrade must be carefully conceived and will require about ten years to implement. The new configuration, known as High Luminosity LHC (HL-LHC), will rely on a number of key innovations that push accelerator technology beyond its present limits. Among these are cutting-edge 11-12 tesla superconducting magnets, compact superconducting cavities for beam rotation with ultra-precise phase control, new technology and physical processes for beam collimation and 300 metre-long high-power superconducting links with negligible energy dissipation. The present document describes the technologies and components that will be used to realise the project and is intended to serve as the basis for the detailed engineering design of HL-LHC.

physics.acc-ph↗

arXiv2015

Electron lenses and cooling for the Fermilab Integrable Optics Test Accelerator

Recently, the study of integrable Hamiltonian systems has led to nonlinear accelerator lattices with one or two transverse invariants and wide stable tune spreads. These lattices may drastically improve the performance of high-intensity machines, providing Landau damping to protect the beam from instabilities, while preserving dynamic aperture. The Integrable Optics Test Accelerator (IOTA) is being built at Fermilab to study these concepts with 150-MeV pencil electron beams (single-particle dynamics) and 2.5-MeV protons (dynamics with self fields). One way to obtain a nonlinear integrable lattice is by using the fields generated by a magnetically confined electron beam (electron lens) overlapping with the circulating beam. The required parameters are similar to the ones of existing devices. In addition, the electron lens will be used in cooling mode to control the brightness of the proton beam and to measure transverse profiles through recombination. More generally, it is of great interest to investigate whether nonlinear integrable optics allows electron coolers to exceed limitations set by both coherent or incoherent instabilities excited by space charge.

physics.acc-ph↗

arXiv2015

Electron Lens as Beam-Beam Wire Compensator in HL-LHC

Current wires are considered for compensation of long-range beam-beam interactions for the High Luminosity upgrade (HL-LHC) of the Large Hadron Collider at CERN. In this note, we demonstrate the advantage of using Electron Lens for this purpose instead of a conventional current-bearing wire.

physics.acc-ph↗