Search NASA⌕ Search

SEARCH · Search NASA

Results for “INJECTOR”

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 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

A Mechanically Tuned Superconducting Main Injector Cavity

Radio Frequency (RF) superconductivity has been a mainstay of accelerator science for decades. However, its benefits have yet to be applied to proton synchrotrons with demanding tuning requirements. For example, the Main Injector (MI), Fermilab's high-energy proton synchrotron, currently utilizes 20+ ferrite-loaded cavities for a targeted 1.2 s acceleration cycle. Harnessing the extremely high gradients associated with superconductivity, the required number of cavities could be reduced by an order of magnitude, dramatically lowering operational power requirements even with cryogenic considerations. Additionally, the current plans for the Fermilab Accelerator Complex Evolution (ACE) initiative involve almost doubling the number of cavities in MI if the same designs are to be used, further highlighting the potential benefits of superconductivity. These advantages are attractive, but to date, no tunable superconducting cavity suitable for MI has been proposed due to the incompatibility of conventional broadband tuning methods with superconductivity. Here, we present a tunable superconducting cavity concept capable of record-breaking performance. Tuning will be accomplished by using high-speed linear actuators to vary the insertion depth of metallic plungers into the cavity volume. This tuning concept is theoretically viable with currently available technology and will be fully compatible with a superconducting cavity.

43 PARTICLE ACCELERATORS↗
DOE OSTI2024

Interface Box for Dual Power Amplifier Modulators in Main Injector

The Proton Improvement Plan II (PIP-II) aims to enhance the current Fermilab particle accelerator complex to intensify and accelerate more beam. To achieve this, a second power amplifier will be added to the Main Injector (MI) cavities. However, the control unit could only read signals coming from the previous power supplies, so the interface box was designed to facilitate the issue.

Ayala, Diana↗
DOE OSTI2024

Performance of the Fermilab Linac Injector

The Fermilab Linac injection line consists of a 35 keV magnetron-type H- ion source, two-solenoid Low Energy Beam Transport (LEBT), 201 MHz 4-rod 750 keV Radio Frequency Quadrupole (RFQ), and a Medium Energy Transport (MEBT) containing 4 quadrupoles and a bunching cavity. The injector delivers 25 mA, 48 s pulses to drift-tube Linac at a repetition rate of 15Hz. The transmission efficiency has been lower than expected since commissioning. Recent beam current measurements suggest that the beam is primarily lost upstream of the RFQ exit. Numerical simulations indicate that ions passing through the non-linear field region of the solenoids could produce a beam with an increased emittance resulting in up to 50 % of the LEBT beam current failing to meet the RFQ acceptance. An aperture restriction was installed upstream of the first solenoid to remove these ions. This report describes the results of measurements and simulations as well as the LEBT tuning.

Jones, Daniel C.↗
DOE OSTI2024

Development and Evaluation of a Novel Fuel Injector Design Method using Hybrid-Additive Manufacturing (Final Report)

The widespread application of metal additive manufacturing (AM) technologies has enabled exploration of complex design spaces to achieve optimally performing components. Current optimization techniques make use of several advanced methods to provide designs that are superior to existing versions. However, they seldom discuss the manufacturability of the optimal designs. The objective of this project was to develop a design optimization tool that simultaneously optimizes fuel injector hardware and the combustor flow field with optimization functions and constraints that consider both combustor performance and manufacturability using advanced AM methods and post-processing. In this way, the resultant hardware design is inherently imbued with our most advanced knowledge of combustion physics and AM methods from its conception.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Evaluating a Transition-Jump System for the Fermilab Main Injector Using Xsuite

We describe an Xsuite simulation framework for the Fermilab Main Injector (MI) along with an evaluation of transition-crossing behaviors in the accelerator. In particular, we studied the introduction of quadrupole magnets into the lattice as part of a transition-jump system that will be implemented through the $2^{nd}$ Proton Improvement Plan (PIP-II). Simulated beam losses spurred by transition-induced instabilities were assessed under several systematic effects, including MI quad errors, magnet-to-magnet variability in the jump magnets, power-supply errors, and timing jitter.

Schreckenberger, Adam Paul [Fermilab] (ORCID:00000↗
DOE OSTI2025

A Simulation of the Fermilab Main Injector Cavities

The Fermilab Main Injector accelerating cavities have sparking issues when they are run at voltages higher than those required by the PIP-II project. This is a problem Fermilab is working on as planning begins for the next upgrade to the accelerator complex. One of the methods being used to address the issue is the development of a CST Microwave Studio simulation to accurately model the PIP-II dual power amplifier cavities and identify which part(s) of the cavity is causing sparking to develop. The model will also be used to determine if changes to the cavity geometry may allow the cavity to be used at higher voltages before sparking occurs

Stevenson, Susanna M. [Fermilab] (ORCID:0009000891↗
DOE OSTI2024

Interface Box for Dual Power Amplifier Modulators in Main Injector

The Proton Improvement Plan II (PIP-II) aims to enhance the current Fermilab particle accelerator complex to intensify and accelerate more beam. To achieve this, a second power amplifier will be added to the Main Injector (MI) cavities. However, the control unit could only read signals coming from the previous power supplies, so the interface box was designed to facilitate the issue.

Ayala, Diana↗
DOE OSTI2024

Interface Box for Dual Power Amplifier Modulators in Main Injector

The Proton Improvement Plan II (PIP-II) aims to enhance the current Fermilab particle accelerator complex to intensify and accelerate more beam. The project will power the beam as it heads from Illinois to the Deep Underground Neutrino Experiment (DUNE) in South Dakota by providing them with neutrinos. To intensify the beam, one of the PIP-II upgrades is to add a second power amplifier (PA) to the existing Main Injector cavities. In turn, this boosts the maximum output power to 400kW per station even though the PIP-II requirement is only 240kW. With more output power, more protons can be accelerated through the particle accelerator and in the case of the DUNE project, this is ideal given that the chance of a neutrino interacting with a proton or a neutron is one in ten billion. The power amplifier is added to the cavity and driven by the modulator. Within the modulator, the control unit receives input signals from the power supplies, moderates they are working properly, and controls the timing of the power up sequence. However, a challenge imposed by an additional PA was that the control unit could only read signals coming from the previous power supplies but not the additional second set. For this reason, the interface box was designed to facilitate the issue.

Ayala, Diana↗
DOE OSTI2024

Performance of the Fermilab Linac Injector

The Fermilab Linac injection line consists of a 35 keV magnetron-type H- ion source, two-solenoid Low Energy Beam Transport (LEBT), 201 MHz 4-rod 750 keV Radio Frequency Quadrupole (RFQ), and a Medium Energy Transport (MEBT) containing 4 quadrupoles and a bunching cavity. The injector delivers 25 mA, 48 s pulses to drift-tube Linac at a repetition rate of 15Hz. The transmission efficiency has been lower than expected since commissioning. Recent beam current measurements suggest that the beam is primarily lost upstream of the RFQ exit. Numerical simulations indicate that ions passing through the non-linear field region of the solenoids could produce a beam with an increased emittance resulting in up to 50 % of the LEBT beam current failing to meet the RFQ acceptance. An aperture restriction was installed upstream of the first solenoid to remove these ions. This report describes the results of measurements and simulations as well as the LEBT tuning.

Jones, Daniel C.↗
DOE OSTI2024

Controlled molecule injector for cold, dense, and pure molecular beams at the European x-ray free-electron laser

A permanently available molecular-beam injection setup for controlled molecules (COMO) was installed and commissioned at the small quantum systems (SQS) instrument at the European x-ray free-electron laser (EuXFEL). A b-type electrostatic deflector allows for pure state-, size-, and isomer-selected samples of polar molecules and clusters. The source provides a rotationally cold (T ≈ 1 K) and dense (ρ ≈ 10 8 cm −3 ) molecular beam with pulse durations up to 100 µs generated by a new version of the Even-Lavie valve. Here, a performance overview of the COMO setup is presented along with characterization experiments performed both with an optical laser at the Center for Free-Electron-Laser Science and with x rays at EuXFEL under burst-mode operation. COMO was designed to be attached to different instruments at the EuXFEL, in particular, the SQS and single particles, clusters, and biomolecules (SPB) instruments. This advanced controlled-molecules injection setup enables x-ray free-electron laser studies using highly defined samples with soft and hard x-ray FEL radiation for applications ranging from atomic, molecular, and cluster physics to elementary processes in chemistry and biology.

He, Lanhai↗
DOE OSTI2024

Properties of V-defect injectors in long wavelength GaN LEDs studied by near-field electro- and photoluminescence

The efficiency of multiple quantum well (QW) light emitting diodes (LEDs) to a large degree depends on uniformity of hole distribution between the QWs. Typically, transport between the QWs takes place via carrier capture into and thermionic emission out of the QWs. In InGaN/GaN QWs, the thermionic hole transport is hindered by the high quantum confinement and polarization barriers. To overcome this drawback, hole injection through semipolar QWs located at sidewalls of V-defects had been proposed. However, in the case of the V-defect injection, strong lateral emission variations take place. In this work, we explore the nature of these variations and the impact of the V-defects on the emission spectra and carrier dynamics. The study was performed by mapping electroluminescence (EL) and photoluminescence (PL) with a scanning near-field optical microscope in LEDs that contain a deeper well that can only be populated by holes through the V-defects. Applying different excitation schemes (electrical injection and optical excitation in the far- and near-field), we have shown that the EL intensity variations are caused by the lateral nonuniformity of the hole injection. We have also found that, in biased structures, the PL intensity and decay time in the V-defect regions are only moderately lower that in the V-defect-free regions thus showing no evidence of an efficient Shockley-–Read–Hall recombination. In the V-defect regions, the emission spectra experience a red shift and increased broadening, which suggests an increase of the In content and well width in the polar QWs close to the V-defects.

Electroluminescence↗
DOE OSTI2026

AMAROK: A Radio Frequency Development Platform for High-Power, Full-Scale Positive Ion Sources for DIII-D Neutral Beam Injectors

Next-generation neutral beam injection (NBI) systems demand RF ion sources capable of efficiently coupling >120 kW at 2–4-MHz frequencies, yet existing designs face voltage standoff and impedance-matching challenges. To address this, the advanced multicoil antenna for RF operations at kilowatts (AMAROK) was developed as a high-power RF inductively coupled plasma (ICP) source delivering up to 200 kW in the 2–4-MHz range via four phase-controlled generators for flexible power sharing. Two antenna designs—a single-strap multiturn (MT) and a multistrap single-turn (ST) design—were evaluated to optimize resonance, impedance matching, and power coupling across plasma loads. Here, a semi-analytical self-resonant frequency (SRF) model, validated experimentally, predicts resonance trends for arbitrary turn counts and tubing diameters, enabling rapid antenna optimization. Strap-to-strap mutual inductance in the ST configuration showed strong spatial dependence, guiding generator operation and total load inductance. These insights informed a custom π -topology matching network, achieving stable impedance matching over a wide range of plasma-driven loads. Collectively, these results position AMAROK as a versatile testbed for advancing high-power RF source technology in fusion NBI applications.

DIII-D↗
DOE OSTI2024

Development of a Method for Shape Optimization for a Gas Turbine Fuel Injector Design Using Metal-Additive Manufacturing

Adjoint shape optimization has enabled physics-based optimal designs for aerodynamic surfaces. Additive manufacturing (AM) makes it possible to manufacture complex shapes. However, there has been a gap between optimal and manufacturable surfaces due to the inherent limitations of commercial computational fluid dynamics (CFD) codes to implement geometric constraints during adjoint computation. In such cases, the design sensitivities are exported and used to perform constrained shape modifications using parametric information stored in computer aided design (CAD) files to satisfy manufacturability constraints. However, modifying the design using adjoint methods in CFD solvers and performing constrained shape modification in CAD can lead to inconsistencies due to different shape parameterization schemes. This paper describes a method to enable the simultaneous optimization of the fluid domain and impose AM manufacturability constraints, resolving one of the key issues of geometry definition for isogeometric analysis. Similar to a grid convergence study, the proposed method verifies the consistencies between shape parameterization techniques present within commercial CAD and CFD software during mesh movement as a part of the adjoint shape optimization routine. By identifying the appropriate parameters essential to a shape optimization study, the error metric between the different parameterization techniques converges to demonstrate sufficient consistencies for justifiable exchange of data between CAD and CFD. For the identified shape optimization parameters, the error metric to measure the deviation between the two parameterization schemes lies within the AM laser-powder bed fusion (L-PBF) process tolerance. Additionally, comparison for subsequent objective function calculations between iterations of the optimization loop showed acceptable differences within 1% variation between the modified geometries obtained using the two parameterization schemes. This method provides justification for the use of multiphysics guided adjoint design sensitivities computed in CFD software to perform shape modifications in CAD to incorporate AM manufacturability constraints during the shape optimization loop such that optimal designs are also additively manufacturable.

33 ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2025

Analog Signal Multiplexing System for the IOTA Proton Injector

he Fermilab Accelerator Science and Technology (FAST) Facility at FNAL is a dedicated research and development center focused on advancing particle accelerator technologies for future applications worldwide. Currently, a key objective of FAST Opera-tions is to commission the 2.5 MeV IOTA Proton Injec-tor (IPI) and enable proton injection into the Integrable Optics Test Accelerator (IOTA) storage ring. The low and medium-energy sections of the IPI include four frame-style dipole trims and two multi-function cor-rectors with independently controlled coils, requiring readout of 32 analog channels for current and voltage monitoring in total. To reduce cost and optimize rack space within the PLC-based control system, a 32-to-4 analog signal multiplexing system was designed and implemented. This system enables real-time readback of excitation parameters from all magnetic correctors. This paper presents the design, construction, implementation, and performance of the multiplexing system.

MacLean, Daniel R. [Fermilab] (ORCID:0000000210103↗
DOE OSTI2026

Spin Diagnostics Using Mott Polarimeter for the EIC Pre-Injector

Polarization measurement and front-end commissioning are critical steps in the EIC preinjector program. We designed a spin-diagnostics beamline at around 4 MeV for front-end commissioning. This paper describes a high-energy Mott polarimeter, including Mott scattering, the Sherman function, and extrapolation toward single elastic scattering in finite-thickness foils. We summarize the key equations used to calculate essential design parameters, including detection time, effective Sherman function, differential cross section, and Mott polarimeter figure of merit. We also present the diagnostics beamline lattice design and kicker design for continuous spin-polarization monitoring. These notes provide concepts, formulas, and methods for diagnostic-beamline design and commissioning measurements.

43 PARTICLE ACCELERATORS↗