Production Of Neutrino Beams Research Articles

Latest results of OPERA

OPERA is a long baseline neutrino experiment which took data between 2008 and 2012 having for goal the observation of the νμ→ντ transition in appearance mode i.e. detecting the τ lepton. The detector was located in the underground Gran Sasso laboratory, 730 km away from the CNGS neutrino beam production at CERN. The collaboration observed 5 ντ candidates which, considering the very low expected background of 0.25 events, allowed for a discovery claim of neutrino oscillation in appearance mode at the level of 5.1 σ. Additional analyses were performed aiming at the possible observation of the νμ→νe transition, and at the search for anomalies related to the possible existence of a sterile neutrino. In this paper, after a short introduction describing the detector, the different results are presented on both oscillation channels including standard 3 flavour scenario and possible new physics.

NuSTORM and a Path to a Muon Collider

This article reviews the current status of the nuSTORM facility and shows how it can be utilized to perform the next step on the path toward the realization of a μ+μ−collider. This review includes the physics motivation behind nuSTORM, a detailed description of the facility and the neutrino beams it can produce, and a summary of the short-baseline neutrino oscillation physics program that can be carried out at the facility. The basic idea for nuSTORM (the production of neutrino beams from the decay of muons in a racetrack-like decay ring) was discussed in the literature more than 30 years ago in the context of searching for noninteracting (sterile) neutrinos. However, only in the past 5 years has the concept been fully developed, motivated in large part by the facility's unmatched reach in addressing the evolving data on oscillations involving sterile neutrinos. Finally, this article reviews the basics of the μ+μ−collider concept and describes how nuSTORM provides a platform to test advanced concepts for six-dimensional muon ionization cooling.

A method for measuring coherent elastic neutrino-nucleus scattering at a far off-axis high-energy neutrino beam target

We present an experimental method for measuring the process of coherent elastic neutrino-nucleus scattering (CENNS). This method uses a detector situated transverse to a high-energy neutrino beam production target. This detector would be sensitive to the low-energy neutrinos arising from decay-at-rest pions in the target. We discuss the physics motivation for making this measurement and outline the predicted backgrounds and sensitivities using this approach. We report a measurement of neutron backgrounds as found in an off-axis surface location of the Fermilab Booster Neutrino Beam (BNB) target. The results indicate that the Fermilab BNB target is a favorable location for a CENNS experiment.

Fermilab main injector: High intensity operation and beam loss control

From 2005 through 2012, the Fermilab Main Injector provided intense beams of 120 GeV protons to produce neutrino beams and antiprotons. Hardware improvements in conjunction with improved diagnostics allowed the system to reach sustained operation at ~400 kW beam power. Transmission was very high except for beam lost at or near the 8 GeV injection energy where 95% beam transmission results in about 1.5 kW of beam loss. By minimizing and localizing loss, residual radiation levels fell while beam power was doubled. Lost beam was directed to either the collimation system or to the beam abort. Critical apertures were increased while improved instrumentation allowed optimal use of available apertures. We will summarize the improvements required to achieve high intensity, the impact of various loss control tools and the status and trends in residual radiation in the Main Injector.

Beta Beams for Neutrino Production

To use accelerated beta active radioactive ions to produce collimated high energy neutrino beams was proposed by P. Zuchelli in 2002. Since then, several ideas related to how to design Beta Beam facilities have been studied. Design studies of an accelerator complex, based on CERN accelerators, have been supported by research programs within the European Commisison FP6 and FP7 frameworks (EURISOL Design Study and EUROnu). In these studies 6He and 18Ne are used as beta emitters to produce antineutrinos and neutrinos respectively. Alternative isotopes for neutrino beam production, 8Li and 8B, are investigated in the now ongoing study, EUROnu. Due to the higher reaction Q-value of these ions, the resulting neutrino energies are higher. The isotopes we need for neutrino beams have to be produced in large quantities using non conventional methods. Latest research on production of isotopes that are presently considered for Beta Beams will be discussed.The work achieved gives a good ground to propose the Beta Beam, which is based on known technology, for neutrino production. In this status review we concentrate on technical issues related to a possible Beta Beam facility using the CERN infrastructure.

Beta Beams for Neutrino Production

To use accelerated beta active ions to produce collimated high energy neutrino beams was proposed by P. Zuchelli in 2002 and studies of a suitable accelerator complex, based on CERN accelerators, have been supported by research programs within the European Commisison FP6 and FP7 frameworks (EURISOL Design Study and EUROnu). In these studies 6He and 18Ne are used as beta emitters to produce antineutrinos and neutrinos respectively. Alternative isotopes for neutrino beam production, giving higher neutrino energies, 8Li and 8B, are investigated in the now ongoing study, EUROnu. The isotopes for neutrino beams have to be produced in large quantities using non conventional methods. The work achieved gives a good ground to propose the Beta Beam, for neutrino production. Technical issues related to a Beta Beam facility using the CERN infrastructure are reviewed.

Short-pulse ECR: A source of multiply charged ions

Extensive investigation is now under way in CERN (European Organization for Nuclear Research) in the framework of the Beta Beam project with the aim of gaining insight into neutrino oscillations. It is suggested that the decay of 6He nuclei produce neutrino beams accelerated to an energy on the order of 100 GeV/nucleon. To this end, it is necessary to generate short-pulse (30–100 μs) beams of multiply charged ions of this isotope. Conventional ECR-based ion sources seem to be inappropriate for this purpose, since the plasma density grows slowly (for more than a millisecond) in this case compared with the desired pulse duration. A design concept of a short-pulse ECR-based source of multiply charged ions is proposed. In experiments with pumping at frequencies of 37.5 and 75.0 GHz, pulses as short as ∼50 μs were obtained. Good agreement between theory and experiments is demonstrated.

Radiation Shielding of a Beta-Beam Rapid Cycling Synchrotron

In a future beta-beam facility, radioactive ions (namely, 6He and 18Ne) are produced, accelerated, and then stored in a large decay ring, where they eventually produce neutrino beams through beta decay. Radiation protection is of great concern for this facility because decay products are present at all energies along the accelerator chain.Experimental data on radioactivity produced by ion accelerators are still poor, and few Monte Carlo codes can transport ions. All present calculations are performed with the Monte Carlo code FLUKA. The radiation environment generated by ion beam losses is compared with the available experimental data. The attenuation length of radiation in concrete is calculated for 6He and 18Ne at four different energies, from 100 to 1650 MeV/u.A preliminary shielding design for the Rapid Cycling Synchrotron, purpose-designed for a beta-beam accelerator chain at CERN, is proposed.

Low-energy neutrino factory design

The design of a low-energy (4 GeV) neutrino factory (NF) is described, along with its expected performance. The neutrino factory uses a high-energy proton beam to produce charged pions. The ${\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}$ decay to produce muons (${\ensuremath{\mu}}^{\ifmmode\pm\else\textpm\fi{}}$), which are collected, accelerated, and stored in a ring with long straight sections. Muons decaying in the straight sections produce neutrino beams. The scheme is based on previous designs for higher energy neutrino factories, but has an improved bunching and phase rotation system, and new acceleration, storage ring, and detector schemes tailored to the needs of the lower energy facility. Our simulations suggest that the NF scheme we describe can produce neutrino beams generated by $\ensuremath{\sim}1.4\ifmmode\times\else\texttimes\fi{}{10}^{21}$ ${\ensuremath{\mu}}^{+}$ per year decaying in a long straight section of the storage ring, and a similar number of ${\ensuremath{\mu}}^{\ensuremath{-}}$ decays.

Physics potential of beta-beams

Beta-beams is a novel concept for the production of neutrino beams exploiting boosted radioactive ions which decay through beta-decay. Here we describe a project, currently under investigation, where such beams are used to address the issue of CP violation in the lepton sector. We also mention the interest of having low-energy beta-beams. The connection to projects for the production of very intense exotic ion beams, like EURISOL, is emphasized.

Large acceptance 30 GeV muon storage rings for neutrino production: lattice design

Two competing goals control the lattice design of a muon storage ring for a neutrino factory [1]. One goal is achieving large transverse and longitudinal acceptances in order to minimize the degree of muon-beam cooling required. (This condition presumes large-emittance muon beams can be effectively accelerated.) The second is provision of a long insertion in which a significant fraction of the stored muons decay and produce a relatively colinear beam of neutrinos. In this work, a 30 GeV muon storage ring is presented which is optimized for acceptance and maximal neutrino-beam production.

Hadronic models and experimental data for the neutrino beam production

The predictions of meson production by 450 GeV/c protons on Be using the Monte Carlo FLUKA standalone and GEANT-FLUKA and GEANT-GHEISHA in GEANT are compared with available experimental measurements. The comparison enlightens the improvements of the hadronic generator models of the present standalone code FLUKA with respect to the 1992 version which is embedded into GEANT-FLUKA. Worse results were obtained with the GHEISHA package. A complete simulation of the SPS neutrino beam line at CERN showed significant variations in the intensity and composition of the neutrino beam when FLUKA standalone instead of the GEANT-FLUKA package is used to simulate particle production in the Be target.

Perspectives for neutrino physics at CERN

The experimental status of neutrino oscillation searches at accelerators is presented, and the future medium and long baseline projects at CERN are discussed, including the knowledge on the neutrino beam production. Perspectives on future neutrino factories based on muon storage rings are also presented.

A high-band neutrino beam

A simple device for producing a high-band neutrino beam is proposed; it consists of a quasi-parabolic profile magnetic horn followed by a narrow circular slit. As an example evaluations are carried out for the West Hall neutrino beam proposed at the CERN SPS, for a primary proton energy E 0 = 400 GeV. The collimation of the resulting parent hadron beam is excellent, giving a spot of ≈ 40 cm maximum radius at the hadron filter, with a very tenuous halo. The overall attenuation of the event rate with respect to the ideally focussed neutrino beam production is ≈ 65%, entirely due to the partial suppression of the low energy neutrinos (E ν ≲ 1 3 E 0) .