High Power Proton Beam Shocks and Magnetohydrodynamics in a Mercury Jet Target for a Neutrino Factory

The feasibility of liquid metal jet targets for secondary particle production with high power proton beams has been studied. The main aspects of the thesis were benchmark experiments covering the behaviour of liquid targets under thermal shock waves induced by high power proton beams, and also magnetohydrodynamic effects. Severe challenges were imposed by safety issues and the restricted beam time to the tests in ISOLDE at CERN and at the High Magnetic Field Laboratory at Grenoble. Restricted access times in high radiation level areas were of the order of minutes and in this short time span, the complete experimental setup had to be performed and verified. The involvement of mercury as liquid target material and its activation during beam tests demanded special confinement precautions. The setup for both experiments was based on the use of a high speed camera system for observation of the mercury target. The presence of high radiation or high magnetic field required the installation of the sensitive camera system at distances up to 15 m. The method of shadow photography had to be used because of the highly reflective surface of mercury. During proton beam tests at the CERN ISOLDE facility and at Brookhaven AGS, the behaviour of a mercury target as a function of various proton beam parameters was analysed. The experimental results allow for extrapolation from the present data by one order of magnitude to the final design of a high power jet target foreseen for a neutrino factory. Observed velocities of the mercury splash were up to 45 m/s. The experimental setup used at the High Magnetic Field Laboratory allowed a successful demonstration of injecting a 12 m/s mercury jet with a diameter d=4 mm into a 20 T solenoidal field. The results of this experiment revealed the magnetohydrodynamic effects, which occur in the free jet and in the supplying mercury circuit, and serve as benchmark for numerical codes. The extrapolation to the nominal parameters of a neutrino factory shows that the concept of a jet target is a valid option

Comparison of Options for the Injector of PS2

In its report, the SPC Review Panel has highlighted that the construction of a 4 MW SPL has to be motivated by the needs of a well-defined and approved physics programme, and that it should be compared with a Rapid Cycling Synchrotron (RCS) when considering only the needs of LHC. This report is meant to answer these remarks by describing the version of the SPL that would be built for the needs of LHC alone (the Low Power SPL or LP-SPL) and by making a preliminary comparison with an RCS

Optimization of Neutrino Rates from the EURISOL Beta-Beam Accelerator Complex

The beta beam concept for the production of intense (anti-)neutrino beams is now well established. A baseline design has recently been published for a beta-beam facility at CERN. It has the virtue of respecting the known limitations of the CERN PS and SPS synchrotrons, but falls short of delivering the requested annual rate of neutrinos. We report on a first analysis to increase the rate using the baseline ions of 6He and 18 Ne. A powerful method to understand the functional dependence of the many parameters that influence the figure of merit for a given facility is available with modern analytical calculation software. The method requires that a symbolic analytical description is produced of the full accelerator chain. Such a description has been made using Mathematica for the proposed beta beam facility at CERN. The direct access from Mathematica to an ORACLE database for reading basic design parameters and re-injecting derived parameters for completion of the parameter list is both convenient and efficient

Proton induced thermal stress-wave measurements using a Laser Doppler Vibrometer

Abstract.: Thermal stress-waves are generated in the solid target material when the proton beam interacts. These stress waves excite natural oscillations of the target or cause plastic deformations. Hence, an experimental setup with a laser Doppler vibrometer [CITE] was developed to investigate free surface vibrations of cylindrical targets. The target configurations for RIB and conventional neutrino beams (CNGS project) were investigated to analyze proton induced thermal stress-wave generation and propagatio

Devotional Biology: A Young-age Creationist, College-level, Conceptual Biology Textbook

Devotional Biology is being developed as a one-semester college-level conceptual biology textbook for non-science majors. Except for presenting a survey of organisms and an introduction to organismal anatomy and physiology (typically reserved for a second-semester course), Devotional Biology covers all the major topics of biology presented in secular texts as well as a few others not usually covered at all. Student surveys indicate students believe they learn biology through the Devotional Biology text. At the same time, Devotional Biology presents biology from the perspective of a distinctly biblical worldview—and on surveys, Devotional Biology students believe they improved their appreciation of biology as well. Devotional Biology also focuses on God, and how His attributes are evident in the biological world—and on surveys, Devotional Biology students believe they improved their recognition of God in the creation, their understanding of God, their relationship to God, and their use of the creation in witness to others. Devotional Biology also assumes a young-age creationist interpretation of biology, critiquing the naturalistic perspective of the field in the process—and on surveys, Devotional Biology students believe they grew in their faith and learned to defend their faith. Devotional Biology also includes responsibilities of believers as priests and kings in God’s creation—and on surveys, Devotional Biology students believe they grew in their understanding of their ethical responsibilities, in their worship of God, and in better ruling over the creation

θ13\theta_{13}, δ\delta and the neutrino mass hierarchy at a γ=350\gamma=350 double baseline Li/B β\beta-Beam

We consider a $\beta$-Beam facility where $^8$Li and $^8$B ions are accelerated at $\gamma = 350$, accumulated in a 10 Km storage ring and let decay, so as to produce intense $\bar \nu_e$ and $\nu_e$ beams. These beams illuminate two iron detectors located at $L \simeq 2000$ Km and $L \simeq 7000$ Km, respectively. The physics potential of this setup is analysed in full detail as a function of the flux. We find that, for the highest flux ($10 \times 10^{18}$ ion decays per year per baseline), the sensitivity to $\theta_{13}$ reaches $\sin^2 2 \theta_{13} \geq 2 \times10^{-4}$; the sign of the atmospheric mass difference can be identified, regardless of the true hierarchy, for $\sin^2 2 \theta_{13} \geq 4\times10^{-4}$; and, CP-violation can be discovered in 70% of the $\delta$-parameter space for $\sin^2 2 \theta_{13} \geq 10^{-3}$, having some sensitivity to CP-violation down to $\sin^2 2 \theta_{13} \geq 10^{-4}$ for $|\delta| \sim 90^\circ$.Comment: 35 pages, 20 figures. Minor changes, matches the published versio

Search for invisible decays of sub-GeV dark photons in missing-energy events at the CERN SPS

We report on a direct search for sub-GeV dark photons (A') which might be produced in the reaction e^- Z \to e^- Z A' via kinetic mixing with photons by 100 GeV electrons incident on an active target in the NA64 experiment at the CERN SPS. The A's would decay invisibly into dark matter particles resulting in events with large missing energy. No evidence for such decays was found with 2.75\cdot 10^{9} electrons on target. We set new limits on the \gamma-A' mixing strength and exclude the invisible A' with a mass < 100 MeV as an explanation of the muon g_\mu-2 anomaly.Comment: 6 pages, 3 figures; Typos corrected, references adde

A Feasibility Experiment of a W-powder Target

The development of high‐powertargetsremains a key R&D actvity for future facilities presently under study like the Neutrino Factory, Muon Collider or upgraded high‐power super beams for long‐baseline neutrino experiments. The choice of materials to sustain the beam power ranging up to MW levels is not trivial.Granular solid targets have been proposed and are being studied as a candidate for such high-power target systems. In the recently commissioned HiRadMat facility at CERN, a feasibility experiment of a tungsten powder target was performed. The experiment was designed to explore for first time the impact of a high‐power proton beam on a static W powder target in a thimble configuration. The diagnostics of the experiment were based on remote high‐speed photography as well as on laser‐doppler vibration measurements of the target containers. Results from the experimental findings are presented in this poster

A 15-T Pulsed Solenoid for a High-Power Target Experiment

The MERIT experiment, which ran at CERN in 2007, is a proof-of-principle test for a target system that converts a 4-MW proton beam into a high-intensity muon beam for either a neutrino factory complex or a muon collider. The target system is based on a free mercury jet that intercepts an intense proton beam inside a 15-T solenoidal magnetic field. Here, we describe the design and performance of the 15-T, liquid-nitrogen-precooled, copper solenoid magnet