V. Pronskikh

Solenoid Magnet System for the Fermilab Mu2e Experiment

The Fermilab Mu2e experiment seeks to measure the rare process of direct muon to electron conversion in the field of a nucleus. Key to the design of the experiment is a system of three superconducting solenoids; a muon production solenoid (PS) which is a 1.8 m aperture axially graded solenoid with a peak field of 5 T used to focus secondary pions and muons from a production target located in the solenoid aperture; an “S shaped” transport solenoid (TS) which selects and transports the subsequent muons towards a stopping target; a detector solenoid (DS) which is an axially graded solenoid at the upstream end to focus transported muons to a stopping target, and a spectrometer solenoid at the downstream end to accurately measure the momentum of the outgoing conversion electrons. The magnetic field requirements, the significant magnetic coupling between the solenoids, the curved muon transport geometry and the large beam induced energy deposition into the superconducting coils pose significant challenges to the magnetic, mechanical, and thermal design of this system. In this paper a conceptual design for the magnetic system which meets the Mu2e experiment requirements is presented.

Challenges and Design of the Transport Solenoid for the Mu2e Experiment at Fermilab

The Fermilab Mu2e experiment seeks to measure the rare process of direct muon to electron conversion in the field of a nucleus. The magnet system for this experiment is made of three warm-bore solenoids: the Production Solenoid (PS), the Transport Solenoid (TS), and the Detector Solenoid (DS). The TS is an “S-shaped” solenoid set between the other bigger solenoids. The Transport Solenoid has a warm-bore aperture of 0.5 m and field between 2.5 and 2.0 T. The PS and DS have, respectively warm-bore aperture of 1.5 m and 1.9 m, and peak field of 4.6 T and 2 T. In order to meet the field specifications, the TS starts inside the PS and ends inside the DS. The strong coupling with the adjacent solenoids poses several challenges to the design and operation of the Transport Solenoid. The coil layout has to compensate for the fringe field of the adjacent solenoids. The quench protection system should handle all possible quench and failure scenarios in all three solenoids. The support system has to be able to withstand very different forces depending on the powering status of the adjacent solenoids. In this paper, the conceptual design of the Transport Solenoid is presented and discussed focusing on these coupling issues and the proposed solutions.

Conceptual design of the Mu2e production solenoid cold mass

The Muon-to-Electron conversion experiment (Mu2e), under development at Fermilab, seeks to detect direct muon to electron conversion to provide evidence for a process violating muon and electron lepton number conservation that cannot be explained by the Standard Model of particle physics. The required magnetic field is produced by a series of superconducting solenoids of various apertures and lengths. This paper describes the conceptual design of the 5 T, 4 m long solenoid cold mass with 1.67 m bore with the emphasis on the magnetic, radiation and thermal analyses.

Conceptual Design of the Mu2e Production Solenoid

The Muon-to-Electron conversion experiment (Mu2e), under development at Fermilab, seeks to detect direct muon to electron conversion to provide evidence for a process violating muon and electron lepton number conservation that cannot be explained by the Standard Model of Particle Physics. The required magnetic field is produced by a series of superconducting solenoids. This paper describes the conceptual design of the 5-T, 4-m-long solenoid with 1.7 m bore with the emphasis on the electromagnetic and structural analyses.

Requirements for the Mu2e Production Solenoid Heat and Radiation Shield

This paper describes the Heat and Radiation Shield (HRS). It serves to protect the superconducting coils of the Mu2e Production Solenoid (PS) from the intense radiation generated by the 8 GeV kinetic energy primary proton beam striking the production target within the warm bore of the PS. This shield also protects the coils in the far upstream end of the Transport Solenoid (TS), a straight section of coils called TS1, at the exit from the PS. The HRS aperture should allow the maximum stopping rate of negative muons in the Detector Solenoid stopping target. Requirements to the Heat and Radiation Shield are discussed in the paper. Work supported by Fermi Research Alliance, LLC under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy. § Corresponding author. Email: vspron@fnal.gov

Linguistic Privilege and Justice: What Can We Learn from STEM?

Abstract The linguistic privilege of native speakers in scientific communication, both oral and written, has been widely reported to influence researchers’ publications and careers in and beyond academia. I examine social structure and communication in the Science, Technology, Engineering and Mathematics (STEM) fields through the example of big science and attempt to answer the question of why language injustice has a less significant effect on non-native scientists and engineers than on philosophy scholars. I do so by scrutinizing the role of signs and nonlinguistic boundary objects in STEM practice and written communication. I also argue that although high-energy physics is relatively linguistically inclusive, it is marked by linguistic privilege of certain groups that bears a structural character which is not common in STEM and is predominant mainly in megascience. I finally suggest that insofar as rhetoric in STEM is generally modest, its practices can serve as an example for analytic philosophy, which also aims at minimizing rhetoric.

The MARS15-based FermiCORD code system for calculation of the accelerator-induced residual dose

Abstract The FermiCORD code system, a set of codes based on MARS15 that calculates the accelerator-induced residual doses at experimental facilities of arbitrary configurations, has been developed. FermiCORD is written in C++ as an add-on to Fortran-based MARS15. The FermiCORD algorithm consists of two stages: 1) simulation of residual doses on contact with the surfaces surrounding the studied location and of radionuclide inventories in the structures surrounding those locations using MARS15, and 2) simulation of the emission of the nuclear decay γ -quanta by the residuals in the activated structures and scoring the prompt doses of these γ -quanta at arbitrary distances from those structures. The FermiCORD code system has been benchmarked against similar algorithms based on other code systems and against experimental data from the CERF facility at CERN, and FermiCORD showed reasonable agreement with these. The code system has been applied for calculation of the residual dose of the target station for the Mu2e experiment and the results have been compared to approximate dosimetric approaches.

Mu2e upgrade physics reach optimization studies for the PIP-II era

The Mu2e experiment at Fermilab is being designed to study the coherent neutrino-less conversion of a negative muon into an electron in the field of a nucleus. This process has an extremely low probability in the Standard Model and its observation would provide unambiguous evidence for BSM physics. The Mu2e design aims to reach a single-event-sensitivity of about

Feasibility Study for a Next-Generation Mu2e Experiment

2.5 \times 10^{17}

MARS15 Code Developments Driven by the Intensity Frontier Needs

and will probe effective new physics mass scales in the 103-104 TeV range, well beyond the reach of the LHC. This work examines the maximum beam power that can be tolerated for beam energies in the 0.5-8 GeV range exploring variations in the geometry in the region of the production target using the MARS15 code. This has implications for how the sensitivity might be further improved with a second generation experiment using an upgraded proton beam from the PIP-II project, which will be capable of providing MW beams to Fermilab experiments later in the next decade.