M. Proga

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.

CHerenkov detectors In mine PitS (CHIPS) Letter of Intent to FNAL

This Letter of Intent outlines a proposal to build a large, yet cost-effective, 100 kton fiducial mass water Cherenkov detector that will initially run in the NuMI beam line. The CHIPS detector (CHerenkov detector In Mine PitS) will be deployed in a flooded mine pit, removing the necessity and expense of a substantial external structure capable of supporting a large detector mass. There are a number of mine pits in northern Minnesota along the NuMI beam that could be used to deploy such a detector. In particular, the Wentworth Pit 2W is at the ideal off-axis angle to contribute to the measurement of the CP violating phase. The detector is designed so that it can be moved to a mine pit in the LBNE beam line once that becomes operational.

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

Profile Monitor SEM's for the NuMI Beam at FNAL

The Neutrinos at the Main Injector (NuMI) project will extract 120 GeV protons from the FNAL Main Injector in 8.56usec spills of 4E13 protons every 1.9 sec. We have designed secondary emission monitor (SEM) detectors to measure beam profile and halo along the proton beam transport line. The SEM?s are Ti foils 5um in thickness segmented in either 1?mm or 0.5?mm pitch strips, resulting in beam loss ~5E-6. We discuss aspects of the mechanical design, calculations of expected beam heating, and results of a beam test at the 8 GeV transport line to MiniBoone at FNAL.The Neutrinos at the Main Injector (NuMI) project will extract 120‐GeV protons from the FNAL Main Injector in 8.56‐μsec spills of 4 × 1013 protons every 1.9 sec. We have designed secondary emission monitor (SEM) detectors to measure beam profile and halo along the proton beam transport line. The SEMs are Ti foils 5 μm in thickness segmented in either 1‐mm or 0.5‐mm pitch strips, resulting in beam loss ∼5 × 10−6. We discuss aspects of the mechanical design, calculations of expected beam heating, and results of a beam test at the 8‐GeV transport line to MiniBoone at FNAL.

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.

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 (

Operation of the NuMI Beam Monitoring System

E_n=1-10

Ion Chamber Arrays for the NuMI Beam at Fermilab

MeV). The sources emit about 10