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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.

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At least 127 records · Page 7
All sourcesNASA NTRSDOE OSTI
NASA NTRS2006

UWB Technology and Applications on Space Exploration

Ultra-wideband (UWB), also known as impulse or carrier-free radio technology, is one promising new technology. In February 2002, the Federal Communications Commission (FCC) approved the deployment of this technology. It is increasingly recognized that UWB technology holds great potential to provide significant benefits in many terrestrial and space applications such as precise positioning/tracking and high data rate mobile wireless communications. This talk presents an introduction to UWB technology and some applications on space exploration. UWB is characterized by several uniquely attractive features, such as low impact on other RF systems due to its extremely low power spectral densities, immunity to interference from narrow band RF systems due to its ultra-wide bandwidth, multipath immunity to fading due to ample multipath diversity, capable of precise positioning due to fine time resolution, capable of high data rate multi-channel performance. The related FCC regulations, IEEE standardization efforts and industry activities also will be addressed in this talk. For space applications, some projects currently under development at NASA Johnson Space Center will be introduced. These include the UWB integrated communication and tracking system for Lunar/Mars rover and astronauts, UWB-RFID ISS inventory tracking, and UWB-TDOA close-in high resolution tracking for potential applications on robonaut.

Ngo, Phong↗
NASA NTRS2004

RF Telemetry System for an Implantable Bio-MEMS Sensor

In this paper, a novel miniature inductor and a pick-up antenna for contact less powering and RF telemetry from implantable bio-MEMS sensors are presented. The design of the inductor and the pick-up antenna are discussed. In addition, the measured characteristics at the design frequency of 330 MHz have been shown.

Simons, Rainee N.↗
DOE OSTI2019

Data Acquisition System for RF Cavity Hadron Monitor

As Fermilab pursues intensity frontier physics, the conventional detectors are not up to the challenge of higher radiation exposure. The detectors in the NuMI beamline rely on knowing the angular distribution of the secondary hadrons in order to infer properties of the resultant neutrino beam. A novel gas-filled RF cavity beam detector is proposed that will be simple and radiation robust in high-radiation environments. Charged particles passing through the cavity produce ionized plasma, which changes the permittivity of the gas and modulate the stored RF field in the cavity. The preliminary beam test of an RF cavity demonstrates the proof of principle of the beam detector. In an effort to acquire a large amount of data for various cavity parameters, an automatic data acquisition (DAQ) system is designed in LabVIEW. The DAQ system utilizes a Real-Time Power meter from Boonton to acquire RF power data from the cavity.

43 PARTICLE ACCELERATORS↗
DOE OSTI2018

JLEIC HOM Damping Study

The JLab Electron-Ion Collider (JLEIC) proposed by Jefferson Lab is a high luminosity collider consists of a few high current sub-complexes, including a 3-12 GeV electron collider ring with up to 3 A beam current, a 20-100 GeV ion collider ring of up to 1 A, and a 20-55 MeV circulation bunched electron cooler ring with up to 1.5 A. Beam induced HOM problems are prevalent in the RF systems of all these accelerator sub-complexes. In this talk, we will present our preliminary HOM damping study in these RF systems.

Guo, Jiquan↗
DOE OSTI2019

Data Acquisition System for RF Cavity Hadron Monitor

As Fermilab pursues intensity frontier physics, the conventional detectors are not up to the challenge of higher radiation exposure. The detectors in the NuMI beamline rely on knowing the beam composition in order to infer properties of the resultant neutrino beam. Anovel gas-filled RF cavity beam detector is proposed that will be simple and radiation robust in high-radiation environments. Charged particles passing through the cavity produce ionized plasma, which changes the permittivity of the gas and modulate the stored RF field in the cavity. The recent preliminary beam result demonstrates the proof of principle of the beam detector. In an effort to acquire a large amount of data for various cavity parameters, an automatic data acquisition(DAQ)system is designed in LabVIEW. The DAQ system utilizes a Real-Time Power meter from Boonton to acquire RF power data from the cavity.

43 PARTICLE ACCELERATORS↗
DOE OSTI2014

Operational experience with CW high gradient and high QL cryomodules

The Continuous Electron Beam Accelerator Facility (CEBAF) energy upgrade from 6 GeV to 12 GeV includes the installation of ten new 100 MV cryomodules (80 cavities). The superconducting RF cavities are designed to operate CW at an accelerating gradient of 19.3 MV/m with a QL of 3×107. The RF system employs single cavity control using new digital LLRF controls and 13 kW klystrons. Recently, all of the new cryomodules and associated RF hardware and software have been commissioned and operated in the CEBAF accelerator. Electrons at linac currents up to 10 ?A have been successfully accelerated and used for nuclear physics experiments. This paper reports on the commissioning and operation of the cryomodules and RF system.

Hovater, J. Curt↗
DOE OSTI2017

A compact linear accelerator based on a scalable microelectromechanical-system RF-structure

Here, a new approach for a compact radio-frequency (RF) accelerator structure is presented. The new accelerator architecture is based on the Multiple Electrostatic Quadrupole Array Linear Accelerator (MEQALAC) structure that was first developed in the 1980s. The MEQALAC utilized RF resonators producing the accelerating fields and providing for higher beam currents through parallel beamlets focused using arrays of electrostatic quadrupoles (ESQs). While the early work obtained ESQs with lateral dimensions on the order of a few centimeters, using a printed circuit board (PCB), we reduce the characteristic dimension to the millimeter regime, while massively scaling up the potential number of parallel beamlets. Using Microelectromechanical systems scalable fabrication approaches, we are working on further red ucing the characteristic dimension to the sub-millimeter regime. The technology is based on RF-acceleration components and ESQs implemented in the PCB or silicon wafers where each beamlet passes through beam apertures in the wafer. The complete accelerator is then assembled by stacking these wafers. This approach has the potential for fast and inexpensive batch fabrication of the components and flexibility in system design for application specific beam energies and currents. For prototyping the accelerator architecture, the components have been fabricated using the PCB. In this paper, we present proof of concept results of the principal components using the PCB: RF acceleration and ESQ focusing. Finally, ongoing developments on implementing components in silicon and scaling of the accelerator technology to high currents and beam energies are discussed.

43 PARTICLE ACCELERATORS↗
DOE OSTI2021

Simulations of RHIC Spin Flipper

The extensive APEX studies of the RHIC Spin Flipper were performed during FY17 achieving up to 97 % spin flip efficiency at both injection (23.8 GeV) and store (255 GeV) energy, using 9 MHz and 197 MHz RF system. The Zgoubi simulations were setup to reproduce the experimental conditions. The results of the APEX measurements and the numerical simulations are compared here, showing a good agreement especially at injection energy. The additional simulations of the spin flip efficiency, with the 28 MHz and 197 MHz RF system, show that a stronger Spin Flipper is needed in order to achieve good (|P f /P i | > 99 %) spin flip efficiency during the nominal physics store running conditions at 255 GeV.

43 PARTICLE ACCELERATORS↗
DOE OSTI2025

Two-Frequency RF Fields Induced Multipactor in Coaxial Transmission Lines

Multipactor is a nonlinear discharge phenomenon that occurs in vacuum RF systems, potentially leading to signal distortion, power loss, and even permanent damage to high-power components. This study presents a detailed investigation of two-surface multipactor in coaxial transmission lines under two-frequency excitation, using one-dimensional (1D) Monte Carlo simulations validated by three-dimensional (3D) Particle-in-Cell (PIC) results and experimental data. Introducing a second carrier mode is shown to suppress multipactor by reshaping and shrinking the susceptibility region, with the extent and location of suppression strongly dependent on the device aspect ratio and the relative phase of the second mode. Distinct suppression patterns emerge across different frequency–gap distance (fd) regimes, and in certain cases, susceptibility expansion is also observed. The study identifies and distinguishes pure and mixed multipactor modes in coaxial geometry, where analytical mode boundaries are not readily defined. Unlike planar systems, pure-mode regions in coaxial structures overlap with mixed-mode domains, complicating classification. Image charge forces are found to have minimal effect on susceptibility thresholds but do influence electron growth rates. These findings provide new insights into waveform-driven control of multipactor in high-power RF systems.

43 PARTICLE ACCELERATORS↗
DOE OSTI2019

A 100-kW 1300-MHz Magnetron With Amplitude and Phase Control for Accelerators

Calabazas Creek Research, Inc. (CCR), in collaboration with Fermilab and Communications and Power Industries, LLC (CPI), developed a 100-kW peak, 10-kW average, 1300-MHz, magnetron-based, RF system with amplitude and phase control for driving accelerators. Phase locking was achieved using an approach originated at Fermilab that uses phase modulation of the locking signal to control the amplitude and phase into a superconducting cavity on a fast time scale. Experimental results, including demonstration of phase locking and amplitude control, are reported.

43 PARTICLE ACCELERATORS↗
DOE OSTI2023

Progress and R/D challenges for FCC-ee SRF

The FCC-ee machines present a huge challenge for the RF systems, which need to be adapted to very diverse beam conditions going from moderate energy and high current for the Z machine to high energy and low beam current for the ttbar. This inverse scaling results naturally from a fixed budget for the synchrotron radiation, which the SRF cavities need to compensate. A global solution was elaborated for the FCC Conceptual Design Report (Abada in Eur Phys J Spec Top 228):261–623, 2019), and is referred here as the baseline. Recently, further studies have led to a new optimized baseline, still based on traditional elliptical cavities. In parallel, a novel concept, named the Slotted Waveguide ELLiptical (SWELL), was proposed with the potential of greatly simplified logistics and reduced costs. Under several aspects, all these changes call for enhanced performance of the RF systems. A vigorous R&D program has therefore continued since the publication of the CDR, with the aim of pushing the performance and demonstrating the feasibility of a more advanced baseline and, more recently, of the SWELL option. The progress and challenges of this ambitious program were presented in the dedicated SRF sessions at FCC week 2022 and are summarized in this paper.

47 OTHER INSTRUMENTATION↗
DOE OSTI2019

Longitudinal Phase Space Dynamics in ERLs

Both the dynamics and the architecture of an energy recovery linac are primarily determined by the longitudinal match. This match can be manipulated by both the magnetic lattice and the RF systems. Here we will present a few examples of systems and the longitudinal solutions found for each. The first application is a free-electron laser application where a short bunch and high peak current are required. The laser increases the energy spread and lowers the energy and this must be compensated in the ERL design. The second application is for an internal target experiment where the need was for small energy spread rather than a short bunch. The third example is for an electron cooler where the bunch must be very long with extremely small energy spread. The beam disruption due to cooling is small but CSR and microbunching effects are a real challenge. In the FEL, the longitudinal matching is mainly accomplished via lattice matching while in the cooler application the RF system is the dominant method to control the phase space. The internal target can be addressed either way.

Benson, Stephen↗
DOE OSTI2014

Beam Pipe HOM Absorber for 750 MHz RF Cavity Systems

This joint project of Muons, Inc., Cornell University and SLAC was supported by a Phase I and Phase II grant monitored by the SBIR Office of Science of the DOE. Beam line HOM absorbers are a critical part of future linear colliders. The use of lossy materials at cryogenic temperatures has been incorporated in several systems. The design in beam pipes requires cylinders of lossy material mechanically confined in such a way as to absorb the microwave energy from the higher-order modes and remove the heat generated in the lossy material. Furthermore, the potential for charge build-up on the surface of the lossy material requires the conductivity of the material to remain consistent from room temperature to cryogenic temperatures. In this program a mechanical design was developed that solved several design constraints: a) fitting into the existing Cornell load vacuum component, b) allowing the use of different material compositions, c) a thermal design that relied upon the compression of the lossy ceramic material without adding stress. Coating experiments were performed that indicated the design constraints needed to fully implement this approach for solving the charge build-up problem inherent in using lossy ceramics. In addition, the ACE3P program, used to calculate the performance of lossy cylinders in beam pipes in general, was supported by this project. Code development and documentation to allow for the more wide spread use of the program was a direct result of this project was well.

43 PARTICLE ACCELERATORS↗
DOE OSTI2016

Residual stress and bending strength of ZnO films deposited on polyimide sheet by RF sputtering system

Zinc oxide (ZnO) films were deposited on a soft polyimide sheet substrate by radio frequency sputtering with a ZnO powder target, and the films' crystal orientations and residual stress were investigated using x-ray diffraction as a function of substrate temperature. C-axis oriented ZnO films were achieved using this ZnO powder target method. The ZnO films exhibited high compressive residual stresses between −0.7 and −1.4 GPa. Finally, the authors examined the strength of the obtained film by applying tensile bending loads. No cracks were observed on the surfaces of the ZnO films after a bending test using cylinders with diameters >25 mm. After a bending test using a cylinder with a diameter of 19 mm, large cracks were formed on the films. Therefore, the authors concluded that the tensile bending strength of the obtained films was greater than ∼420 MPa.

42 ENGINEERING↗
DOE OSTI2024

Control System for RF OPM

SAND2025-01910O This software built in LabVIEW FPGA provides experimental control of the RF OPM prototype via a reconfigurable NI I/O card. It samples the analog input, processes it on the FPGA in real time, and generates control and feedback outputs to control and optimize the operation of the device. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.

Bainbridge, Jonathan↗
DOE OSTI2015

Muon Beam Emittance Evolution in the Helical Ionization Cooling Channel for Bright Muon Sources

The six-dimensional ionization cooling is essential to design a bright muon source. A geometry constraint is a challenge issue in a compact helical cooling channel (HCC). Especially, the HCC requires a large bore helical magnet and a compact helical RF system to incorporate the RF into the magnet chamber. A new emittance evolution has been designed to mitigate the geometry constraint. The HCC was functionally separated into three parts sections. The lattice at the initial section provides a large transverse acceptance by using a strong helical focus magnet. Once the transverse beam size is small enough to get into the compact RF the HCC lattice in the middle section generates a large longitudinal beta tune to dominate the longitudinal cooling. Consequently, the longitudinal emittance becomes smaller than the transverse one at the end of middle section. In the final section, the magnetic field strength is gradually reduced to match out the helical channel to the straight solenoid. As a result, the emittance exchange takes place and the final transverse emittance becomes smaller than the longitudinal one. The new emittance evolution scenario will be discussed in this presentation.

Derbenev, Yaroslav↗
NASA NTRS1968

Diversity RF receiving system with improved phase-lock characteristics

Improved diversity receiving system automatically utilizes the combined output from its two independent receiving channels /with cross- polarized receiving antennas/ to increase the reliability of maintaining the requisite phase lock for optimum signal reception. It is adapted for use with AM, PM, or narrow band FM signals.

Di Losa, V. J.↗