628 research outputs found
Beam Test of a Segmented Foil SEM Grid
A prototype Secondary-electron Emission Monitor (SEM) was installed in the 8
GeV proton transport line for the MiniBooNE experiment at Fermilab. The SEM is
a segmented grid made with 5 um Ti foils, intended for use in the 120 GeV NuMI
beam at Fermilab. Similar to previous workers, we found that the full
collection of the secondary electron signal requires a bias voltage to draw the
ejected electrons cleanly off the foils, and this effect is more pronounced at
larger beam intensity. The beam centroid and width resolutions of the SEM were
measured at beam widths of 3, 7, and 8 mm, and compared to calculations.
Extrapolating the data from this beam test, we expect a centroid and width
resolutions of 20um and 25 um, respectively, in the NuMI beam which has 1 mm
spot size.Comment: submitted to Nucl. Instr. Meth.
Secondary Electron Yield Measurements of Fermilab's Main Injector Vacuum Vessel
We discuss the progress made on a new installation in Fermilab's Main
Injector that will help investigate the electron cloud phenomenon by making
direct measurements of the secondary electron yield (SEY) of samples irradiated
in the accelerator. In the Project X upgrade the Main Injector will have its
beam intensity increased by a factor of three compared to current operations.
This may result in the beam being subject to instabilities from the electron
cloud. Measured SEY values can be used to further constrain simulations and aid
our extrapolation to Project X intensities. The SEY test-stand, developed in
conjunction with Cornell and SLAC, is capable of measuring the SEY from samples
using an incident electron beam when the samples are biased at different
voltages. We present the design and manufacture of the test-stand and the
results of initial laboratory tests on samples prior to installation.Comment: 3 pp. 3rd International Particle Accelerator Conference (IPAC 2012)
20-25 May 2012, New Orleans, Louisian
Beam Tests of Ionization Chambers for the NuMI Neutrino Beam
We have conducted tests at the Fermilab Booster of ionization chambers to be
used as monitors of the NuMI neutrino beamline. The chambers were exposed to
proton fluxes of up to 10 particles/cm/1.56s. We studied space
charge effects which can reduce signal collection from the chambers at large
charged particle beam intensities.Comment: submitted to IEEE Trans Nucl. Sc
Beam-Based Alignment of the NuMI Target Station Components at FNAL
The Neutrinos at the Main Injector (NuMI) facility is a conventional
horn-focused neutrino beam which produces muon neutrinos from a beam of mesons
directed into a long evacuated decay volume. The relative alignment of the
primary proton beam, target, and focusing horns affects the neutrino energy
spectrum delivered to experiments. This paper describes a check of the
alignment of these components using the proton beam.Comment: higher resolution figures available on Fermilab Preprint Server (see
SPIRES entry), accepted for publication in Nucl. Instr. and Meth.
Secondary Beam Monitors for the NuMI Facility at FNAL
The Neutrinos at the Main Injector (NuMI) facility is a conventional neutrino
beam which produces muon neutrinos by focusing a beam of mesons into a long
evacuated decay volume. We have built four arrays of ionization chambers to
monitor the position and intensity of the hadron and muon beams associated with
neutrino production at locations downstream of the decay volume. This article
describes the chambers' construction, calibration, and commissioning in the
beam.Comment: Accepted for publication in Nucl. Instr. Meth.
The NuMI Neutrino Beam and Potential for an Off-Axis Experiment
The Neutrinos at the Main Injector (NuMI) facility at Fermilab is under
construction and due to begin operations in late 2004. NuMI will deliver an
intense beam of variable energy 2-20 GeV directed into the Earth at
58 mrad. Several aspects of the design are reviewed, and potential limitations
to the ultimate neutrino flux are described. In addition, potential
measurements of neutrino mixing properties are described.Comment: talk given at NuFact '02, Imperial College London, proceedings to
appear in J. Phys. G, revised to add a referenc
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