Showing 80 results for Author: Alexander V. Aleksandrov
Sep, 2026
Conference Paper
We report a novel particle-beam diagnostic technique that employs a customized pulsed laser source with a user-defined macropulse structure. This approach enables nonintrusive, single-bunch diagnostics of an operational hydrogen ion beam in a high-power particle accelerator.
Mar, 2026
Conference Paper
The SNS beam test facility is a model of the SNS front end (source through medium-energy transport). On-going work at the BTF focuses on accurate modeling of the beam distribution to enable the prediction of halo losses (>100 parts per million). This presentation will discuss the latest progress towards this goal, including recent results after a reconfiguration of the tes…
Mar, 2026
Conference Paper
This paper presents the method and results for measuring the full six-dimensional phase space of a low energy, high intensity hadron beam. This was done by combining four-dimensional emittance measurement techniques along with dispersion measurement and a beam shape monitor to provide the energy and arrival time components. The measurements were performed on the new Beam T…
Mar, 2026
Conference Paper
Ongoing studies at the Spallation Neutron Source (SNS) Beam Test Facility (BTF) seek to understand and model bunch dynamics in a high-power LINAC front-end. The BTF has recently been upgraded with a reconfiguration from a U-shaped line to a Straight line. We report the current state of model benchmarking, with a focus on RMS beam sizes within the FODO line. The beam measur…
Mar, 2026
Conference Paper
Laser wire has been used for nonintrusive profile and emittance measurements of operational hydrogen ion (H-) beam at the SNS linac. In this talk, we will describe the following recent developments in the laser wire system. 1) An upgraded light source and laser transport line which enables novel measurement capabilities including longitudinal profile measurement and high-e…
Mar, 2026
Conference Paper
Hadron beams develop intensity-dependent transverse-longitudinal correlations within radio-frequency quadrupole (RFQ) accelerating structures. These correlations are only visible in six-dimensional phase space and are destroyed by reconstructions from low-dimensional projections. In this work, we estimate the effect of artificial decorrelation on the beam dynamics in the S…
Mar, 2026
Conference Paper
We demonstrate a novel technique to measure the longitudinal profile of an operational hydrogen ion (Hâ») beam in a non intrusive, real-time fashion. The measurement is conducted based on the photo-ionization of the ion beam with a phase modulated laser comb pico-second laser pulses with controllable temporal structure. The measurement technique has been applied to a 1-Ge…
Mar, 2026
Conference Paper
No simulation of intense beam transport has accurately reproduced measurements at the level of beam halo. One potential explanation of this discrepancy is a lack of knowledge of the initial distribution of particles in six-dimensional (6D) phase space. A direct 6D measurement of an ion beam was recently performed at the Spallation Neutron Source (SNS) Beam Test Facility (B…
Mar, 2026
Conference Paper
Work at the SNS beam test facility has focused on high dimensional and high dynamic range measurements of the medium energy (2.5 Mev) beam distribution. This is motivated by the need to understand and predict beam losses down to one-part-per-million. The initial demonstration of full-and-direct 6D phase space measurement was done at a current of 40 mA transported through t…
Sep, 2025
Journal
We propose and demonstrate a nonintrusive diagnostic technique for measuring longitudinal bunch profiles of an operational high-power hydrogen ion (H−) beam in the Spallation Neutron Source (SNS) linear accelerator at Oak Ridge National Laboratory (ORNL). The technique consists of a laser wire formed by a picosecond pulsed laser beam and a virtual slit created by controlli…
Nov, 2024
Conference Paper
The Beam Test Facility (BTF) is a functional duplicate of the Spallation Neutron Source (SNS) frontend with a 2.5 MeV beam on which the first six-dimensional phase space measurement has been completed. This presentation will show the technical underpinnings involved in performing the 6D scan with the BTF. The first part will examine the diagnostic setup involving apertures…
Nov, 2024
Conference Paper
The goal of this experiment is to measure the full 6D phase space of a low energy, high intensity hadron beam. We use 4D emittance measurement techniques for the transverse plane combined with dispersion measurement and a beam shape monitor to provide the longitudinal phase space. The Beam Testing Facility (BTF) at the Spallation Neutron Source (SNS), a 2.5 MeV functional…