R. Zwaska

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.

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.

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.

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 µm 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

Segmented Foil SEM Grids at Fermilab

We present recent beam data from a new design of a profile monitor for proton beams at Fermilab. The monitors, consisting of grids of segmented Ti foils 5μm thick, are secondary-electron emission monitors (SEM’s). We review data on the device’s precision on beam centroid position, beam width, and on beam loss associated with the SEM material placed in the beam.

Cycle-to-Cycle Extraction Synchronization of the Fermilab Booster for Multiple Batch Injection to the Main Injector

We report on a system to ensure cycle-to-cycle synchronization of beam extraction from the Fermilab Booster accelerator to the Main Injector. Such synchronization is necessary for multiple batch operation of the Main Injector for the Run II upgrade of anti-proton production using slip-stacking in the Main Injector, and for the NuMI (Neutrinos at the Main Injector) neutrino beam. To perform this task a system of fast measurements and feedback controls the longitudinal progress of the Booster beam throughout its acceleration period by manipulation of the transverse position maintained by the LLRF (Low-level Radio Frequency) system.

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.

Study of neutron-induced ionization in helium and argon chamber gases

Ion chambers used to monitor the secondary hadron and tertiary muon beam in the NuMI neutrino beamline will be exposed to background particles, including low energy neutrons produced in the beam dump. To understand these backgrounds, we have studied Helium- and Argon-filled ionization chambers exposed to intense neutron fluxes from PuBe neutron sources (

Enhanced dynamical stability with harmonic slip stacking

E_n=1-10

Beam Tests of Beampipe Coatings for Electron Cloud Mitigation in Fermilab Main Injector

MeV). The sources emit about 10