Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “BEAM PROFILES”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 records

Evaluation of accuracy and resolution of the electron beam profile scanner at the Fermilab Main Injector

The objective of this work is to assess the accuracy of measurements made by the Electron Beam Profile Scanner (EBPS), which captures the trajectory of an electron beam with and without a proton beam present. The proton beam induces deflection in the electron beam, which is influenced by proton charges.For high-resolution images, the probe beam needs to be of high intensity, small diameter, and small divergence, evaluated using a YAG screen and an optical transition radiation (OTR) screen. Additionally, the point spread function (PSF) will be calculated to characterize the optical system's properties using ZEMAX software. The capabilities of the Hamamatsu Charge-Injection Device (CID) camera and Kimball Physics electron gun (e-gun) will be considered for accuracy.

Mwaniki, Matilda [IIT, Chicago; Fermilab]↗

Mirascope Luminescent Beam Profile Monitor

Advanced beam diagnostics are essential for reliable operation of high-performance accelerators and the intense beams produced by them. Non-invasive diagnostics can be used continuously with intense beams, while invasive techniques interfere with the beams and distort the beam profiles. In addition, traditional solid-based beam monitoring instrumentation produces unacceptable levels of radiation operating in high power beam environments. Noninvasive determination of accelerated particle distributions and profiles is the most difficult task of bunch diagnostics. Muons, Inc. proposed to develop non-interfering residual-gas beam profile monitors for transfer lines with pulse-to-pulse precision of better than 0.1 mm in position and size that will operate over a wide range of proton beam intensities including those needed for multi-MW beams of future facilities. The approach was to develop a low mass residual-gas profile monitor, where beam induced fluorescence (BIF) will be used to monitor the beam profile. An original scheme of light collection using a mirascope, an optical device invented in the 16th century, is proposed. The gas composition and pressure in the beam pipe are locally controlled to minimize unwanted radiation and to improve resolution.

43 PARTICLE ACCELERATORS↗

An online, energy-resolving beam profile detector for laser-driven proton beams

In this paper, a scintillator-based online beam profile detector for the characterization of laser-driven proton beams is presented. Using a pixelated matrix with varying absorber thicknesses, the proton beam is spatially resolved in two dimensions and simultaneously energy-resolved. A thin plastic scintillator placed behind the absorber and read out by a CCD camera is used as the active detector material. The spatial detector resolution reaches down to ∼4 mm and the detector can resolve proton beam profiles for up to 9 proton threshold energies. With these detector design parameters, the spatial characteristics of the proton distribution and its cut-off energy can be analyzed online and on-shot under vacuum conditions. The paper discusses the detector design, its characterization and calibration at a conventional proton source, as well as the first detector application at a laser-driven proton source.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

Ion beam profiling system and related methods

An ion beam profiling system include a beam profiling element, an ion sensitive element electrically isolated from the beam profiling element, an ion source configured to emit an ion beam at the beam profiling element and the ion sensitive element, and a current measuring device coupled to the ion sensitive element. The beam profiling element includes a plate of material having two parallel major surfaces, a first slit aperture extending through the plate of material and having a first longitudinal length extending in a direction parallel to the two parallel major surfaces, and a second slit aperture extending through the plate of material and having a second longitudinal length extending in a direction parallel to the two parallel major surfaces, wherein the first longitudinal length of the first slit aperture is perpendicular to the second longitudinal length of the second slit aperture.

Taylor, Chase N.↗

R & D of a Gas-Filled RF Beam Profile Monitor for Intense Neutrino Beam Experiments

We report the R&D of a novel radiation-robust hadron beam profile monitor based on a gas-filled RF cavity for intense neutrino beam experiments. An equivalent RF circuit model was made and simulated to optimize the RF parameter in a wide beam intensity range. As a result, the maximum acceptable beam intensity in the monitor is significantly increased by using a low-quality factor RF cavity. The plan for the demonstration test is set up to prepare for future neutrino beam experiments.

43 PARTICLE ACCELERATORS↗

Measurement techniques using the electron beam profile scanner at the Fermilab Main Injector

This work presents techniques for non-invasive transverse profile measurements of high-intensity proton beams using an Electron Beam Profile Scanner (EBPS). The EBPS utilizes low-energy electrons as a probe to analyze the transverse size of proton beams, allowing for potential analysis on a single-bunch basis. Recent upgrades to the Fermilab Main Injector have enhanced beam power on target to 1 MW, with future developments targeting 2 MW. The higher beam power has increased the demand for non-invasive diagnostics, as invasive methods can disrupt operations.The techniques presented include 1) the slow scan technique, which serves as a proof of concept for the probe beam, 2) the one-shot scan technique for measuring horizontal beam profiles, and 3) the raster scan technique for analyzing horizontal beam profiles as a function of the longitudinal distribution of the beam. The profiles obtained will be crucial for studying and understanding instabilities in high-power, high-intensity proton beams. This will contribute to optimizing the operation of high-power proton accelerators by minimizing beam loss, activation, and damage to both the diagnostics and the accelerator components.

Mwaniki, Matilda [IIT, Chicago]↗

New x-ray pink-beam profile monitor system for the SPring-8 beamline front-end

A new beam profile monitoring system for the small X-ray beam exiting from the SPring-8 front-end was developed and tested at BL13XU. This system is intended as a screen monitor and also as a position monitor even at beam currents of 100 mA by using photoluminescence of a chemical vapor deposition-grown diamond film. To cope with the challenge that the spatial distribution of the photoluminescence in the vertical direction is too flat to detect the beam centroid within a limited narrow aperture, a filter was installed that absorbs the fundamental harmonic concentrated in the beam center, which resulted in “de-flattening” of the vertical distribution. For the measurement, the filter crossed the photon beam vertically at high speed to withstand the intense heat flux of the undulator pink-beam. A transient thermal analysis, which can simulate the movement of the irradiation position with time, was conducted to determine the appropriate configuration and the required moving speed of the filter to avoid accidental melting. In a demonstration experiment, the vertically separated beam profile could be successfully observed for a 0.8 × 0.8 mm{sup 2} beam shaped by an XY slit and with a fundamental energy of 18.48 keV. The vertical beam centroid could be detected with a resolution of less than 0.1 mm.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

Fast Scanning Diamond Detector for Electron Beam Profile Monitoring

The first prototype of a fast scanning diamond beam profile detector (DBPD) suitable for invasive high power CW electron beam core profile measurements in transmittance mode was developed. It consists of a multi-strip solid state diamond detector to scan with high speed (up to 1 m/s) and precision (about 5 μm) through the core of an electron beam. The diamond sensor was made from a thin polycrystalline diamond (PCD) plate with highly B-doped diamond conductive strips both grown by CVD. Transient currents from the multi-strip detector were measured with fast digitizing electrometers. Successful operation of the DBPD was demonstrated for pulsed (5 Hz) and CW (78 kHz) CeC beams, including the detector’s ability to withstand a 20 sec insertion into the CW CeC beam core. The X-Y beam spatial profile was measured in one scan. Thermal modelling demonstrated a manageable thermal impact even from a relatively long insertion of the diamond sensor into the CW CeC core and very short (0.2 s) insertion into the CW LEReC beam core. Electrical impedance modelling of the detector and vacuum chamber assembly demonstrated minimal impact on beam line impedance with diamond sensor insertion.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

On the Bandwidth and Beam Profile Characteristics of a Simple Low-Frequency Collimated Ultrasound Beam Source

We numerically investigate the bandwidth and collimation characteristics of ultrasound beams generated by a simple collimated ultrasound beam source that consists of a piezoelectric disk operated near its radial mode resonances. We simulate the ultrasound beam generated in a fluid medium as a function of the excitation frequency for two cases: (1) free piezoelectric disk that corresponds to zero-traction along the lateral edge and (2) fixed piezoelectric disk that corresponds to zero-displacement along the lateral edge. We present and discuss the physical mechanism underpinning the frequency-dependent collimation and bandwidth properties of the ultrasound beams. We observe that the collimated beam generated by the free disk repeatedly lengthens/shortens and also extends/retracts sidelobes with increasing frequency. Alternatively, fixing the piezoelectric disk results in a consistent beam profile shape across a broad range of frequencies. This facilitates generating broadband signals such as a Gaussian pulse or chirp, which are common in ultrasound imaging. Thus, the fixed piezoelectric disk finds application as a collimated ultrasound beam source in a wide range of applications including medical ultrasound imaging, scanning acoustic microscopy, sonar detection, and other nondestructive ultrasound inspection techniques.

47 OTHER INSTRUMENTATION↗

Development of a Gas Sheet Beam Profile Monitor for IOTA

A nitrogen gas sheet will measure the two dimensional transverse profile of the 2.5 MeV proton beam in IOTA. The beam lifetime is limited by the interaction with the gas, thus a minimally invasive instrument is required. To produce a gas sheet with the desired density and thickness, various nozzle types are being investigated, including rectangular capillary tubes for gas injection and skimmers for final shaping of the gas. It is essential to meet vacuum requirements in the interaction chamber while maintaining the precise thickness and density of the gas, without significantly affecting the beam lifetime. The current design of a gas sheet beam profile monitor and present status will be discussed.

43 PARTICLE ACCELERATORS↗

Beam Profile Measurements Utilizing an Amplitude Modulated Pulsed Fiber Laser at PIP2IT

Fermilab is undertaking the development of a new 800 MeV superconducting RF linac to replace its present normal conducting 400 MeV linac. The PIP-II linac consists of a warm front-end generating 2 mA of 2.1 MeV H⁻ followed immediately by a series of superconducting RF cryomodules to 800 MeV. To limit the potential damage to the superconducting RF cavities, PIP-II will utilize laser-based monitors to obtain beam profiles via photoionization. This paper will present the results of transverse and longitudinal beam profile measurements using a prototype profile monitor that was tested with 2.1 MeV H⁻ beam at the PIP-II Injector Test (PIP2IT) accelerator. This prototype profile monitor utilizes a high repetition rate fiber laser and fiber optic transport into the PIP2IT enclosure. In addition, results will be shown of narrow-band electron detection from amplitude modulated laser pulses.

43 PARTICLE ACCELERATORS↗

Transverse beam profile measurement system for the Duke storage ring

The transverse beam emittance is a crucial parameter determining the brightness of an electron storage ring based synchrotron radiation source. The beam emittance is typically determined using the transverse electron beam size and the beta function at a particular location. For a low energy storage ring, the direct imaging method using visible/UV light has many advantages, including being simple, straightforward, and cost-effective. The resolution of such a system can be quite adequate for measuring electron beams with a reasonably large transverse beam size. In this work, we present the development of a new transverse beam profile measurement system for the Duke storage ring. This new system has been characterized to allow absolute measurements of the electron beam size while achieving better system resolution than previously thought possible for the direct imaging technique. The preliminary measurement results show that this system is capable of measuring the horizontal beam size over a wide range of the electron beam energies and currents. The system has also been demonstrated as a useful tool to study the intra-beam scattering related emittance increase in the storage ring.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

Beam Profile Measurements at the DARHT II Accelerator Exit

Measurements of the beam profile at the exit of the DARHT II accelerator have been made. The 1.65-kA, 17-MeV DARHT-II linear induction accelerator [1] is unique in that its beam pulse has a long, 1.6-ns flattop during which the kinetic energy varies by less than ±2%. Four short pulses are selected out of this long pulse in the downstream transport [2], and these are converted to bremsstrahlung for multi-pulse flash radiography of high explosive driven hydrodynamic experiments. The objective of the measurements was to demonstrate the capability to make these measurements with a long beam pulse of high intensity. Many observations can be made on the basis of these measurements. These are described herein.

43 PARTICLE ACCELERATORS↗

Single-shot measurement of longitudinal phase space beam profile in an electron storage ring

A novel scheme to measure the longitudinal emittance and phase space profile in an electron storage ring by using correlations between time and the vertical coordinate, and between energy and the horizontal coordinate, is proposed. This longitudinal profile measurement scheme will help to demonstrate recent results of advanced studies for manipulating the longitudinal beam profile and for investigating beam instability in an electron storage ring.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

Analytical & Experimental Study of Radio Frequency Cavity Beam Profile Monitor

The purpose of this analytical and experimental study is multifold: 1) To explore a new, radiation-robust, hadron beam profile monitor for intense neutrino beam applications; 2) To test, demonstrate, and develop a novel gas-filled Radio-Frequency (RF) cavity to use in this monitoring system. Within this context, the first section of the study analyzes the beam distribution across the hadron monitor as well as the ion-production rate inside the RF cavity. Furthermore a more effecient pixel configuration across the hadron monitor is proposed to provide higher sensitivity to changes in beam displacement. Finally, the results of a benchtop test of the tunable quality factor RF cavity will be presented. The proposed hadron monitor configuration consists of a circular array of RF cavities located at a radial distance of 7cm { corresponding to the standard deviation of the beam due to scatering { and a gas-filled RF cavity with a quality factor in the range 400 - 800.

43 PARTICLE ACCELERATORS↗

Accuracy and Resolution Evaluation of the E-Beam Profile Scanner at the Fermilab Main Injector

The objective of this work is to assess the accuracy of measurements made by the Electron Beam Profile Scanner (EBPS), which captures the trajectory of an electron beam with and without a proton beam present. The proton beam induces deflection in the electron beam, which is influenced by proton charges. For high-resolution images, the probe beam needs to be of high intensity, small diameter, and small divergence, evaluated using a phosphor screen and an optical transition radiation (OTR) screen. The capabilities of the Kimball Physics electron gun (eGun) will be considered for accuracy. Additionally, the Zemax software will be utilized to characterize the optical elements.

Mwaniki, M. W. [IIT, Chicago] (ORCID:0000000169057↗

WIRE SCANNER FOR HIGH INTENSITY BEAM PROFILE DIAGNOSITICS

A control and data acquisition system of a high speed wire scanner is developed for high intensity beam profile diagnostics. The control system of the wire scanner includes two IOCs, a Soft IOC and a VME IOC. The Soft IOC connects with an Aerotech Ensemble motor drive through EPCIS motor record and controls the movement of the wire scanner. An Electrical Input card samples the real-time position of the wire through an incremental encoder, and generates a pulse to synchronize a VME ADC data acquisition card, which digitizes and samples the beam-induced signal after pre-amplification. A VME Relay Output card is installed to control the Brake Solenoid and Actuator Solenoid. All the VME I/O cards are installed on one VME crate and controlled by the VME IOC. The system configuration and software of the wire scanner are under development.

Yan, J.↗