J. McDonald

Ionization chambers for monitoring in high-intensity charged particle beams

Radiation-hard ionization chambers were tested using an intense electron beam from the accelerator test facility at the Brookhaven National Laboratory. The detectors were designed to be used as the basic element for monitoring muons in the Main Injector Neutrino beamline at the Fermi National Accelerator Laboratory. Measurements of linearity of response, voltage dependence, and the onset of ionization saturation as a function of gap voltage were performed.

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/sup 12/ particles/cm/sup 2//1.56 /spl mu/s. We studied potential space charge effects which could reduce signal collection from the chambers at large charged particle beam intensities.

Nuclear effects and the NuTeV sin2 θW measurement

Abstract NuTeV measures sin 2 θ W by comparing neutral and charged current cross-sections on a heavy nuclear target, and finds a value of sin 2 θ W (on-shell) = 0.2277 ± 0.0013(stat) ± 0.0009(syst), approximately 3σ from the predicted value. We discuss the possibility that nuclear effects on parton distribution functions or cross-sections may be responsible for the discrepancy.

High energy neutrino scattering results from NuTeV

The NuTeV experiment at Fermilab has obtained a unique high statistics sample of neutrino and antineutrino interactions using a novel high-energy sign-selected neutrino beam. Recent results from this sample are presented including a precision measurement of the electroweak parameter sin2≡W, which is observed to be three standard deviations above the standard model prediction.

Ion Chambers for Monitoring the NuMI Neutrino Beam at Fermilab

The Neutrinos at the Main Injector (NuMI) beamline will deliver an intense muon neutrino beam by focusing a beam of mesons into a long evacuated decay volume. The beam must be steered with 1‐mRad angular accuracy toward the Soudan Underground Laboratory in northern Minnesota. We have built 4 arrays of ionization chambers to monitor the neutrino beam direction and quality. The arrays are located at 4 stations downstream of the decay volume, and measure the remnant hadron beam and tertiary muons produced along with neutrinos in meson decays. We review how the monitors will be used to make beam quality measurements, and as well review chamber construction details, radiation damage testing, calibration, and test beam results.

Cross Section Measurements and Charm Production in the NuTeV Experiment

The NuTeV experiment at Fermilab obtained pure high statistics samples of neutrino and antineutrino interactions using its sign‐selected beam. Preliminary inclusive charged current differential cross sections of neutrino and antineutrino interactions on iron are presented, along with preliminary measurements of F2(x, Q2) and xF3(x, Q2). Preliminary results from the next‐to‐leading order QCD analysis of deep inelastic charged current dimuon data are also shown.

Operation of the NuMI Beam Monitoring System

The NuMI (Neutrinos at the Main Injector) facility produces an intense neutrino beam for experiments. The NuMI Beam Monitoring system consists of four arrays of ion chambers that measure the intensity and distribution of the remnant hadron and tertiary muon beams produced in association with the neutrinos. The ion chambers operate in an environment of high particle fluxes and high radiation.

Ion Chamber Arrays for the NuMI Beam at Fermilab

The Neutrinos at the Main Injector (NuMI) beamline will deliver an intense νμbeam by focusing a beam of mesons into a long evacuated decay volume. We have built 4 arrays of ionization chambers to monitor the ν beam direction and quality. The arrays are located at 4 stations downstream of the decay volume, and measure the remnant hadron beam and tertiary muons produced along with neutrinos in meson decays.