How to Build a Superbeam

A discussion of design issues for future conventional neutrino beam-lines with proton beam power above a megawatt.Comment: 5 pp. 11th International Workshop on Neutrino Factories, Superbeams and Betabeams: NuFact09. 20-25 Jul 2009. Chicago, Illinoi

How to Build a Superbeam

A discussion of design issues for future conventional neutrino beam-lines with proton beam power above a megawatt. There are several conventional neutrino beam-lines currently in operation that are designed to handle proton beam power of a fraction of a mega-watt. By conventional neutrino beam-line is meant one where accelerated protons strike a target to produce charged pions, which are magnetically focused and allowed to decay to neutrinos. Several laboratories are considering accelerator upgrades over the next decade that could provide proton beam power above a mega-watt for neutrino beam-lines (see Table 1); conventional neutrino beams at such high power have been labeled Superbeams. Based on current experience, the most significant technical issues for this next generation of high-power neutrino beam-lines are radiation protection, target survivability, and reliability/reparability. A few examples are given of extrapolating from NuMI to LBNE (the proposed beam-line from FNAL to DUSEL in South Dakota using protons from the Project X accelerator upgrade)

Upgrades to the Fermilab Numi Beamline

The NuMI beamline at Fermilab has been delivering high-intensity muon neutrino beams to the MINOS experiment since the spring of 2005. A total of 3.4 x 10{sup 20} protons has been delivered to the NuMI target and a maximum beam power of 320 kW has been achieved. An upgrade of the NuMI facility increasing the beam power capability to 700 kW is planned as part of the NOvA experiment. The plans for this upgrade are presented and the possibility of upgrading the NuMI beamline to handle 1.2 MW is considered

Overview of the LBNE Neutrino Beam

The Long Baseline Neutrino Experiment (LBNE) will utilize a neutrino beamline facility located at Fermilab. The facility is designed to aim a beam of neutrinos toward a detector placed at the Deep Underground Science and Engineering Laboratory (DUSEL) in South Dakota. The neutrinos are produced in a three-step process. First, protons from the Main Injector hit a solid target and produce mesons. Then, the charged mesons are focused by a set of focusing horns into the decay pipe, towards the far detector. Finally, the mesons that enter the decay pipe decay into neutrinos. The parameters of the facility were determined by an amalgam of the physics goals, the Monte Carlo modeling of the facility, and the experience gained by operating the NuMI facility at Fermilab. The initial beam power is expected to be {approx}700 kW, however some of the parameters were chosen to be able to deal with a beam power of 2.3 MW

An improved measurement of muon antineutrino disappearance in MINOS

We report an improved measurement of muon anti-neutrino disappearance over a distance of 735km using the MINOS detectors and the Fermilab Main Injector neutrino beam in a muon anti-neutrino enhanced configuration. From a total exposure of 2.95e20 protons on target, of which 42% have not been previously analyzed, we make the most precise measurement of the anti-neutrino "atmospheric" delta-m squared = 2.62 +0.31/-0.28 (stat.) +/- 0.09 (syst.) and constrain the anti-neutrino atmospheric mixing angle >0.75 (90%CL). These values are in agreement with those measured for muon neutrinos, removing the tension reported previously.Comment: 5 pages, 4 figures. In submission to Phys.Rev.Let

Improved Search for Muon-Neutrino to Electron-Neutrino Oscillations in MINOS

We report the results of a search for ν_e appearance in a ν_μ beam in the MINOS long-baseline neutrino experiment. With an improved analysis and an increased exposure of 8.2×10^(20) protons on the NuMI target at Fermilab, we find 2sin^2(θ_(23))sin^2(2θ_(13))<0.12(0.20) at 90% confidence level for δ=0 and the normal (inverted) neutrino mass hierarchy, with a best-fit of 2sin^2(θ_(23))sin^2(2θ_(13))=0.041^(+0.047)_(-0.031)(0.079^(+0.071)_(-0.053). The θ_(13)= 0 hypothesis is disfavored by the MINOS data at the 89% confidence level

Search for the disappearance of muon antineutrinos in the NuMI neutrino beam

We report constraints on antineutrino oscillation parameters that were obtained by using the two MINOS detectors to measure the 7% muon antineutrino component of the NuMI neutrino beam. In the Far Detector, we select 130 events in the charged-current muon antineutrino sample, compared to a prediction of 136.4 ± 11.7(stat)^(+10.2)_(-8.9)(syst) events under the assumption │Δm^2│ = 2.32 X 10^(-3) eV^2, sin^2(2θ) = 1.0