Search NASA⌕ Search

SEARCH · Search NASA

Results for “Accelerators, Instrumentation”

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 127 records · Page 7

Pion contamination in the MICE muon beam

Here, the international Muon Ionization Cooling Experiment (MICE) will perform a systematic investigation of ionization cooling with muon beams of momentum between 140 and 240\,MeV/c at the Rutherford Appleton Laboratory ISIS facility. The measurement of ionization cooling in MICE relies on the selection of a pure sample of muons that traverse the experiment. To make this selection, the MICE Muon Beam is designed to deliver a beam of muons with less than $\sim$1% contamination. To make the final muon selection, MICE employs a particle-identification (PID) system upstream and downstream of the cooling cell. The PID system includes time-of-flight hodoscopes, threshold-Cherenkov counters and calorimetry. The upper limit for the pion contamination measured in this paper is $f_\pi < 1.4\%$ at 90% C.L., including systematic uncertainties. Therefore, the MICE Muon Beam is able to meet the stringent pion-contamination requirements of the study of ionization cooling.

43 PARTICLE ACCELERATORS↗

Preparing the MAX IV storage rings for timing-based experiments

Time-resolved experimental techniques are increasingly abundant at storage ring facilities. Recent developments in accelerator technology and beamline instrumentation allow for simultaneous operation of high-intensity and timing-based experiments. The MAX IV facility is a state-of-the-art synchrotron light source in Lund, Sweden, that will come into operation in 2016. As many storage ring facilities are pursuing upgrade programs employing strong-focusing multibend achromats and passive harmonic cavities (HCs) in high-current operation, it is of broad interest to study the accelerator and instrumentation developments required to enable timing-based experiments at such machines. In particular, the use of hybrid filling modes combined with pulse picking by resonant excitation or pseudo single bunch has shown promising results. These methods can be combined with novel beamline instrumentation, such as choppers and instrument gating. In this paper we discuss how these techniques can be implemented and employed at MAX IV.

43 PARTICLE ACCELERATORS↗

The conversion of CESR to operate as the Test Accelerator, CesrTA. Part 3: Electron cloud diagnostics

Cornell's electron/positron storage ring (CESR) was modified over a series of accelerator shutdowns beginning in May 2008, which substantially improves its capability for research and development for particle accelerators. CESR's energy span from 1.8 to 5.6 GeV with both electrons and positrons makes it ideal for the study of a wide spectrum of accelerator physics issues and instrumentation related to present light sources and future lepton damping rings. Additionally a number of these are also relevant for the beam physics of proton accelerators. This paper is the third in a series of four describing the conversion of CESR to the test accelerator, CESRTA. The first two papers discuss the overall plan for the conversion of the storage ring to an instrument capable of studying advanced accelerator physics issues [1] and the details of the vacuum system upgrades [2]. This paper focuses on the necessary development of new instrumentation, situated in four dedicated experimental regions, capable of studying such phenomena as electron clouds (ECs) and methods to mitigate EC effects. The fourth paper in this series describes the vacuum system modifications of the superconducting wigglers to accommodate the diagnostic instrumentation for the study of EC behavior within wigglers. Lastly, while the initial studies of CESRTA focused on questions related to the International Linear Collider damping ring design, CESRTA is a very versatile storage ring, capable of studying a wide range of accelerator physics and instrumentation questions.

43 PARTICLE ACCELERATORS↗

IOTA (Integrable Optics Test Accelerator): Facility and experimental beam physics program

The Integrable Optics Test Accelerator (IOTA) is a storage ring for advanced beam physics research currently being built and commissioned at Fermilab. It will operate with protons and electrons using injectors with momenta of 70 and 150 MeV/c, respectively. The research program includes the study of nonlinear focusing integrable optical beam lattices based on special magnets and electron lenses, beam dynamics of space-charge effects and their compensation, optical stochastic cooling, and several other experiments. In this article, we present the design and main parameters of the facility, outline progress to date and provide the timeline of the construction, commissioning and research. Finally, the physical principles, design, and hardware implementation plans for the major IOTA experiments are also discussed.

43 PARTICLE ACCELERATORS↗

An absolute recoil-carbon polarimeter for polarized light-ions at the BNL Booster

We describe a recoil-carbon polarimeter for the BNL Booster synchrotron capable of measuring the transverse polarization of both the polarized proton beam and the polarized 3 He ion beam throughout the acceleration cycle. The instrument addresses a critical gap in the BNL polarized beam program: no independent polarization measurement currently exists in the injector chain between the 200 MeV Linac polarimeter and the AGS. The proposed new polarimeter will provide continuous, absolute polarization measurements at the Booster stage, supplying additional anchor points for the polarization transmission through the accelerator chain. The polarimeter 9 is based on elastic pC and 3 He C scattering from a thin internal carbon target, with detection of the recoil 12 C nucleus in a fixed six-station silicon detector ring. A single detector geometry provides continuous kinematic coverage from injection to extraction for both beam species without mechanical adjustment. For pC scattering, the available data and the Bonin parametrization provide a well-established basis for estimating the analyzing power and figure of merit over the Booster energy range; for 3 He C the sole experimental anchor is a measurement at 443 MeV, and the Booster polarimeter itself is identified as the instrument to map the analyzing power across the remainder of the acceleration ramp by a ramp-and-return calibration that anchors the absolute 3 He polarization scale to a few percent. Provision for future deuteron polarimetry is incorporated in the chamber design without modification to the existing geometry. With appropriate detector upgrades, the same recoil-carbon technique can be extended to deuteron beams, for which analyzing power data are already available, and, with future analyzing-power measurements, also to 6 Li and 7 Li beams, making the polarimeter a versatile instrument for the full range of light polarized ion species anticipated at BNL.

43 PARTICLE ACCELERATORS↗

Characterisation of the PXIE Allison-type emittance scanner

An Allison-type emittance scanner has been designed for PXIE at FNAL with the goal of providing fast and accurate phase space reconstruction. The device has been modified from previous LBNL/SNS designs to operate in both pulsed and DC modes with the addition of water-cooled front slits. Extensive calibration techniques and error analysis allowed confinement of uncertainty to the <5% level (with known caveats). With a 16-bit, 1 MHz electronics scheme the device is able to analyse a pulse with a resolution of 1 μs, allowing for analysis of neutralisation effects. As a result, this paper describes a detailed breakdown of the R&D, as well as post-run analysis techniques.

43 PARTICLE ACCELERATORS↗

12 GeV detector technology at Jefferson Lab

The Thomas Jefferson National Accelerator Facility (JLab) is presently in the middle of an upgrade to increase the energy of its CW electron beam from 6 GeV to 12 GeV along with the addition of a fourth experimental hall. Driven both by necessity and availability, novel detectors and electronics modules have been used in the upgrade. One such sensor is the Silicon Photomultiplier (SiPM), specifically a Multi-Pixel Photon Counter (MPPC), which is an array of avalanche photodiode pixels operating in Geiger mode that are used to sense photons. The SiPMs replace conventional photomultiplier tubes and have several distinct advantages including the safe operation in a magnetic field and the lack of need for high voltage. Another key to 12 GeV success is advanced fast electronics. Jlab will use custom 250 MHz and 125 MHz 12-bit analog to digital converters (ADCs) and time to digital converters (TDCs) all of which take advantage of VME Switched Serial (VXS) bus with its GB/s high bandwidth readout capability. These new technologies will be used to readout drift chambers, calorimeters, spectrometers and other particle detectors at Jlab once the 12 GeV upgrade is complete. The largest experiment at Jlab utilizing these components is GlueX - an experiment in the newly constructed Hall D that will study the photoproduction of light mesons in the search for hybrid mesons. The performance of these components and their respective detectors will be presented.

43 PARTICLE ACCELERATORS↗

Accelerator Science: Circular vs. Linear

Particle accelerator are scientific instruments that allow scientists to collide particles together at incredible energies to study the secrets of the universe. However, there are many manners in which particle accelerators can be constructed. In this video, Fermilab’s Dr. Don Lincoln explains the pros and cons of circular and linear accelerators.

43 PARTICLE ACCELERATORS↗

Intial performance from the NOvA surface prototype detector

NOvA, the NuMI Off-Axis {nu}{sub e} Appearance experiment, will study {nu}{sub {mu}} {yields} {nu}{sub e} oscillations characterized by the mixing angle {Theta}{sub 13}. Provided {Theta}{sub 13} is large enough, NOvA may ultimately determine the ordering of the neutrino masses and measure CP violation in neutrino oscillations. A complementary pair of detectors will be constructed {approx}14 mrad off beam axis to optimize the energy profile of the neutrinos. This system consists of a surface based 14 kTon liquid scintillator tracking volume located 810 km from the main injector source (NuMI) in Ash River, Minnesota and a smaller underground 222 Ton near detector at the Fermilab. The first neutrino signals at the Ash River Site are expected prior to the 2012 accelerator shutdown. In the meantime, a near detector surface prototype has been completed and neutrinos from two Fermilab sources have been observed using the same highly segmented PVC and liquid scintillator detector system that will be deployed in the full scale experiment. Design and initial performance characteristics of this prototype system are being fed back into the design for the full NOvA program.

43 PARTICLE ACCELERATORS↗

Hydrostatic Level Sensors as High Precision Ground Motion Instrumentation for Tevatron and Other Energy Frontier Accelerators

Particle accelerators require very tight tolerances on the alignment and stability of their elements: magnets, accelerating cavities, vacuum chambers, etc. In this article we describe the Hydrostatic Level Sensors (HLS) for very low frequency measurements used in a variety of facilities at Fermilab. We present design features of the sensors, outline their technical parameters, describe their test and calibration procedures, discuss different regimes of operation and give few illustrative examples of the experimental data. Detail experimental results of the ground motion measurements with these detectors will be presented in subsequent papers.

43 PARTICLE ACCELERATORS↗

Dipole Magnets Above 20 Tesla: Research Needs for a Path via High-Temperature Superconducting REBCO Conductors

To enable the physics research that continues to deepen our understanding of the Universe, future circular colliders will require a critical and unique instrument—magnets that can generate a dipole field of 20 T and above. However, today’s maturing magnet technology for low-temperature superconductors (Nb-Ti and Nb 3 Sn) can lead to a maximum dipole field of around 16 T. High-temperature superconductors such as REBCO can, in principle, generate higher dipole fields but significant challenges exist for both conductor and magnet technology. To address these challenges, several critical research needs, including direct needs on instrumentation and measurements, are identified to push for the maximum dipole fields a REBCO accelerator magnet can generate. We discuss the research needs by reviewing the current results and outlining the perspectives for future technology development, followed by a brief update on the status of the technology development at Lawrence Berkeley National Laboratory. We present a roadmap for the next decade to develop 20 T-class REBCO accelerator magnets as an enabling instrument for future energy-frontier accelerator complex.

47 OTHER INSTRUMENTATION↗

High power targets: Challenges of next-generation high-intensity neutrino beams

High power target systems are crucial elements in enabling future neutrino and other rare particle beams. These systems transform intense source of protons into secondary particles of interest to enable new scientific discoveries. As primary beam intensities increase in next-generation multi-megawatt accelerator facilities, high power target systems face key challenges. Thermal shock and radiation damage effects in beam-intercepting devices were identified as the leading cross-cutting challenges of high-power target facilities. Target materials R&D to address these challenges are therefore essential to enable and ensure reliable operation of future accelerator target facilities. This paper provides an overview of the R&D activities underway to help support high power target systems development for next-generation multi-MW facilities.

43 PARTICLE ACCELERATORS↗

Emissivity measurements of CuCrZr alloy

The Facility for Rare Isotope Beams (FRIB) heavy-ion accelerator, in user operation since 2022, produces rare isotope beams via interactions of high-intensity stable ion beams with a graphite production target. Approximately 20–40% of the primary beam power is deposited in the target, while the remaining 60–80% is absorbed by the beam dump. The minichannel beam dump (MCBD), currently operated at 20 kW and designed for operation up to 50 kW, uses CuCrZr alloy absorber plates. Thermal validation and thermal cycling tests of the MCBD were conducted at the Applied Research Laboratory (ARL) at Pennsylvania State University. Temperature measurements were obtained from an infrared (IR) camera. Since accurate temperature determination requires reliable emissivity values, the emissivity of CuCrZr was measured using the IR camera validated against thermocouple reference temperatures up to approximately 650 °C. The measurements were conducted under a vacuum level of approximately 10 -5 torr to minimize emissivity variations due to surface oxidation. The emissivity of CuCrZr was determined to be 0.057 ± 0.009 using a constant fit to the measured data over the surface temperature range from 100–650 °C.

Accelerator Subsystems and Technologies↗

Recent T980 Crystal Collimation Studies at the Tevatron Exploiting a Pixel Detector System and a Multi-Strip Crystal Array

With the shutdown of the Tevatron, the T-980 crystal collimation experiment at Fermilab has been successfully completed. Results of dedicated beam studies in May 2011 are described in this paper. For these studies, two multi-strip crystals were installed in the vertical goniometer and an O-shaped crystal installed in a horizontal goniometer. A two-plane CMS pixel detector was also installed in order to enhance the experiment with the capability to image the profile of crystal channeled or multiple volume reflected beam. The experiment successfully imaged channeled beam from a crystal for 980-GeV protons for the first time. This new enhanced hardware yielded impressive results. The performance and characterization of the crystals studied have been very reproducible over time and consistent with simulations.

43 PARTICLE ACCELERATORS↗