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Title: Secondary Beam Monitors for the NuMI Facility at FNAL

Abstract

The Neutrinos at the Main Injector (NuMI) beam principally supplies high energy neutrinos to the Main Injector Neutrino Oscillation Search (MINOS) experiment, which is investigating neutrino oscillations. The NuMI beamline accepts 120 GeV protons from the Fermilab Main Injector and steers them toward a graphite target to produce a secondary meson beam that decays to neutrinos and muons. Due to the constraints placed on beam quality, ionization chamber arrays are developed to measure the primary beam and tertiary charged particles to monitor beam quality, beam direction, and the operational integrity of the upstream beamline components. This thesis describes the research and development of these beam monitors and their demonstrated utility for MINOS and NuMI.

Authors:
 [1]
  1. Texas U.
Publication Date:
Research Org.:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org.:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
OSTI Identifier:
1418800
Report Number(s):
FERMILAB-MASTERS-2006-11
1649183
DOE Contract Number:
AC02-07CH11359
Resource Type:
Thesis/Dissertation
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS

Citation Formats

Indurthy, Dharmaraj. Secondary Beam Monitors for the NuMI Facility at FNAL. United States: N. p., 2006. Web. doi:10.2172/1418800.
Indurthy, Dharmaraj. Secondary Beam Monitors for the NuMI Facility at FNAL. United States. doi:10.2172/1418800.
Indurthy, Dharmaraj. Sun . "Secondary Beam Monitors for the NuMI Facility at FNAL". United States. doi:10.2172/1418800. https://www.osti.gov/servlets/purl/1418800.
@article{osti_1418800,
title = {Secondary Beam Monitors for the NuMI Facility at FNAL},
author = {Indurthy, Dharmaraj},
abstractNote = {The Neutrinos at the Main Injector (NuMI) beam principally supplies high energy neutrinos to the Main Injector Neutrino Oscillation Search (MINOS) experiment, which is investigating neutrino oscillations. The NuMI beamline accepts 120 GeV protons from the Fermilab Main Injector and steers them toward a graphite target to produce a secondary meson beam that decays to neutrinos and muons. Due to the constraints placed on beam quality, ionization chamber arrays are developed to measure the primary beam and tertiary charged particles to monitor beam quality, beam direction, and the operational integrity of the upstream beamline components. This thesis describes the research and development of these beam monitors and their demonstrated utility for MINOS and NuMI.},
doi = {10.2172/1418800},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Sun Jan 01 00:00:00 EST 2006},
month = {Sun Jan 01 00:00:00 EST 2006}
}

Thesis/Dissertation:
Other availability
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  • 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.
  • The neutrinos at the main injector (NuMI) neutrino beam facility began operating at the Fermi National Accelerator Laboratory in 2005. NuMI produces an intense, muon-neutrino beam to a number of experiments. Foremost of these experiments is MINOS-the Main Injector Neutrino Oscillation Search-that uses two neutrino detectors in the beam, one at Fermilab and one in northern Minnesota, to investigate the phenomenon of neutrino oscillations.
  • This thesis presents the results of an analysis of v μ disappearance with the MINOS experiment, which studies the neutrino beam produced by the NuMI facility at Fermi National Accelerator Laboratory. The rates and energy spectra of charged current v μ interactions are measured in two similar detectors, located at distances of 1 km and 735 km along the NuMI beamline. The Near Detector provides accurate measurements of the initial beam composition and energy, while the Far Detector is sensitive to the effects of neutrino oscillations. The analysis uses data collected between May 2005 and March 2007, corresponding to an exposure of 2.5 x 10 20 protons on target. As part of the analysis, sophisticated software was developed to identify muon tracks in the detectors and to reconstruct muon kinematics. Events with reconstructed tracks were then analyzed using a multivariate technique to efficiently isolate a pure sample of charged current v μ events. An extrapolation method was also developed, which produces accurate predictions of the Far Detector neutrino energy spectrum, based on data collected at the Near Detector. Finally, several techniques to improve the sensitivity of an oscillation measurement were implemented, and a full study of the systematic uncertainties was performed. Extrapolating from observations at the Near Detector, 733 ± 29 Far Detector events were expected in the absence of oscillations, but only 563 events were observed. This deficit in event rate corresponds to a significance of 4.3 standard deviations. The deficit is energy dependent and clear distortion of the Far Detector energy spectrum is observed. A maximum likelihood analysis, which fully accounts for systematic uncertainties, is used to determine the allowed regions for the oscillation parameters and identifies the best fit values as Δmmore » $$2\atop{32}$$ = 2.29$$+0.14\atop{-0.14}$$ x 10 -3 eV 2 and sin 223 > 0.953 (68% confidence level). The models of neutrino decoherence and decay are disfavored at the 5.0σ and 3.2σ levels respectively, while the no oscillation model is excluded at the 9.4σ level.« less
  • The Main Injector Neutrino Oscillation Search (MINOS) is a two detector long-baseline neutrino experiment designed to study the disappearance of muon neutrinos. MINOS will test the v μ → v τ oscillation hypothesis and measure precisely Δm 23 2 and sin 223 oscillation parameters. The source of neutrinos for MINOS experiment is Fermilab's Neutrinos at the Main Injector (NuMI) beamline. The energy spectrum and the composition of the beam is measured at two locations, one close to the source and the other 735 km down-stream in the Soudan Mine Underground Laboratory in northern Minnesota. The precision measurement of the oscillation parameters requires an accurate prediction of the neutrino flux at the Far Detector. This thesis discusses the calculation of the neutrino flux at the Far Detector and its uncertainties. A technique that uses the Near Detector data to constrain the uncertainties in the calculation of the flux is described. The data corresponding to an exposure of 2.5 x 10 20 protons on the NuMI target is presented and an energy dependent disappearance pattern predicted by neutrino oscillation hypotheses is observed in the Far Detector data. The fit to MINOS data, for given exposure, yields the best fit values for Δmmore » $$2\atop{23}$$ and sin 223 to be (2.38$$+0.20\atop{-0.16}$$) x 10 -3 eV 2/c 4and 1.00 -0.08, respectively.« less
  • There is now substantial evidence that the proper description of neutrino involves two representations related by the 3 x 3 PMNS matrix characterized by either distinct mass or flavor. The parameters of this mixing matrix, three angles and a phase, as well as the mass differences between the three mass eigenstates must be determined experimentally. The Main Injector Neutrino Oscillation Search experiment is designed to study the flavor composition of a beam of muon neutrinos as it travels between the Near Detector at Fermi National Accelerator Laboratory at 1 km from the target, and the Far Detector in the Soudanmore » iron mine in Minnesota at 735 km from the target. From the comparison of reconstructed neutrino energy spectra at the near and far location, precise measurements of neutrino oscillation parameters from muon neutrino disappearance and electron neutrino appearance are expected. It is very important to know the neutrino flux coming from the source in order to achieve the main goal of the MINOS experiment: precise measurements of the atmospheric mass splitting |Δm 23 2|, sin 2 θ 23. The goal of my thesis is to accurately predict the neutrino flux for the MINOS experiment and measure the neutrino mixing angle and atmospheric mass splitting.« less