Understanding the effect of radiation on the functional properties of epoxy resins is crucial for their application in future particle accelerators like the Future Circular Collider (FCC). We compare ...the irradiation induced aging rates of six epoxy resin systems that can be used for the vacuum impregnation of magnet coils. Aging is assessed based on Dynamical Mechanical Analysis (DMA), 3-point bending and outgassing tests. DMA storage and loss moduli evolutions reveal the effect of the competing influence of cross-linking and chain scission on the glass transition temperature ( T g ). The same proton and gamma irradiation dose has a similar effect on the thermomechanical epoxy resin properties. Aging rates differ strongly for the different resins, and the fastest aging is observed for the MY750 resin system, which T g decreases with a rate of about minus 9 °C/MGy.
Accurate measurements of physical processes in high energy frontier experiments demand exceptional spatial, temporal, and energy precision to discern the physics behind high-energy particle jets. ...Calorimeters, like other detection systems, must be able to meet these increasingly challenging performance requirements. In the prospective TeV-scale Muon Collider, the primary hurdle in designing detectors and devising event reconstruction algorithms is the challenge posed by Beam-Induced Background (BIB). Nevertheless, it is conceivable to mitigate the impact of BIB on the Muon Collider's calorimeter by capitalizing on certain characteristics and ensuring key features such as high granularity, precise timing, longitudinal segmentation, and superior energy resolution. This is what the here described Research and Development is trying to achieve with an innovative semi-homogeneous electromagnetic calorimeter constructed from stackable and interchangeable modules composed of lead fluoride crystals (PbF2). These modules are equipped with surface-mount UV-extended Silicon Photomultipliers (SiPMs) and are collectively referred to as the Crilin calorimeter (CRystal calorImeter with Longitudinal INformation). The challenge lies in making sure this calorimeter can operate effectively within an extremely harsh radiation environment, enduring an annual neutron flux of <inline-formula> <tex-math notation="LaTeX">10^{14}~n_{1\text {MeV}}/\text {cm}^{2} </tex-math></inline-formula> and a total ionizing dose (TID) of 10 kGy. In this article, the radiation tolerance measured in several irradiation campaigns is discussed, and the timing performances during a test beam at CERN-H2 with 120-GeV electrons. Additionally, a description of the latest prototype, Proto-1, is provided together with the results of the latest low-energy beam test at the LNF beam test facility (BTF) with 450 MeV electrons.
The Mu2e experiment at the Fermilab Muon Campus will search for the coherent neutrinoless conversion of a muon into an electron in the field of an aluminum nucleus with a sensitivity improvement by a ...factor of 10 000 over existing limits. Such a charged lepton flavor-violating reaction probes new physics at a scale unavailable with direct searches at either present or planned high-energy colliders. The Mu2e Trigger and Data Acquisition (TDAQ) system exploits otsdaq as its online Data Acquisition System (DAQ) solution. Developed at Fermilab, otsdaq integrates both the artdaq DAQ and the art analysis frameworks for event transfer, filtering, and processing. otsdaq is an online DAQ software suite with a focus on flexibility and scalability and provides a multi-user, web-based, interface accessible through a web browser. The read out controllers (ROCs) stream out zero-suppressed data continuously from the detector subsystems to the data transfer controllers (DTCs). The data stream is then read over the peripheral component interconnect express (PCIe) bus to a software filter algorithm that selects events which are combined with the data flux coming from a cosmic-ray veto (CRV) system. The detector control system (DCS) has been developed using the experimental physics and industrial control system (EPICS) open source platform for monitoring, controlling, alarming, and archiving. The DCS has been integrated into otsdaq . A prototype of the TDAQ system and the DCS has been built at Fermilab's Feynman Computing Center. In this article, we report on the progress of the integration of this prototype in the online otsdaq software.
The Mu2e experiment at Fermilab searches for the charged-lepton flavor violating (CLFV) conversion of a negative muon into an electron in the field of an aluminum nucleus, with a distinctive ...signature of a monoenergetic electron of energy slightly below the muon rest mass (104.967 MeV). The Mu2e goal is to improve by four orders of magnitude the search sensitivity with respect to the previous experiments. Any observation of a CLFV signal will be a clear indication of new physics. The Mu2e detector is composed of a tracker, an electromagnetic calorimeter, and an external veto for cosmic rays surrounding the solenoid. The calorimeter plays an important role in providing particle identification capabilities, a fast online trigger filter, a seed for track reconstruction while working in vacuum, in the presence of 1-T axial magnetic field and in a harsh radiation environment. The calorimeter requirements are to provide a large acceptance for 100-MeV electrons and reach at these energies: 1) a time resolution better than 0.5 ns; 2) an energy resolution <10%; and 3) a position resolution of 1 cm. The calorimeter design consists of two disks, each one made of 674-undoped cesium iodine crystals read by two large area arrays of UV-extended silicon photomultipliers (SiPMs). We report here the construction and the test of the Module-0 prototype. The Module-0 has been exposed to an electron beam in the energy range around 100 MeV at the Beam Test Facility in Frascati. Preliminary results of timing and energy resolution at normal incidence are shown. A discussion of the technical aspects of the calorimeter engineering is also reported in this paper.
Introduction
This study aimed to illustrate the validity of the treatment with vertebroplasty (VP) in patients with aggressive or symptomatic vertebral hemangioma (VH) with or without epidural ...extension.
Methods
From January 2003 to December 2007, 24 consecutive patients have been treated with VP, for a total of 36 vertebral bodies affected by VH: two cervical, ten dorsal, 24 lumbar. All the patients complained of a pain syndrome resistant to continuous medical medication; four of 24 patients also presented aggressive magnetic resonance features of the vertebral lesion and two patients showed also epidural extension. A unipedicular approach has been performed in 16 patients; a bipedicular approach has been performed in six, while for the cervical spine an anterior–lateral approach with manual dislocation of the carotid axis has always been performed. Bone biopsy was never done. All procedures have been carried out with local anesthesia, except for the treatment of the cervical hemangiomas which has always been performed under general anesthesia. Four vertebral bodies in the same session have been treated in one case.
Results
Results have been evaluated with the visual analog scale and the Oswestry Disability Index methods. In all the patients, in the following 24–72 h, a successful outcome has been observed with a complete resolution of pain symptom. Extravertebral vascular or discal cement leakage has been observed in four patients, without any onset of clinical radicular syndrome due to epidural diffusion. Clinical and radiological follow-up until 4 years has been performed in 12 patients and it showed stability of the treatment and absence of pain.
Conclusions
Percutaneous treatment with VP for aggressive and symptomatic vertebral hemangiomas even with epidural extension is a valuable, mini-invasive, and quick method that allows a complete and enduring resolution of the painful vertebral symptoms without findings of fracture of a vertebral body adjacent or distant to the one treated.
The Mu2e experiment is constructing a calorimeter consisting of 1348 undoped cesium iodide (CsI) crystals in two disks. Each crystal has a dimension of 34 × 34 × 200 mm3 and is readout by a ...large-area silicon photomultipliers array. A series of technical specifications on mechanical and optical parameters was defined according to the calorimeter physics requirements. Preproduction CsI crystals were procured from three firms: Amcrys, Saint-Gobain, and Shanghai Institute of Ceramics. We report the quality assurance on crystal's scintillation properties and their radiation hardness against ionization dose and neutrons. With a fast decay time of about 30 ns and a light output of more than 100 p.e./MeV measured by a bialkali photomultiplier tube, undoped CsI crystals provide a cost-effective solution for Mu2e.
The Mu2e experiment at Fermilab will search for the charged lepton flavor violating neutrino-less conversion of a negative muon into an electron in the field of an aluminum nucleus <xref ...ref-type="bibr" rid="ref1">1 , <xref ref-type="bibr" rid="ref2">2 . The Mu2e detector is comprised of a tracker, an electromagnetic calorimeter, and an external veto for cosmic rays. The calorimeter plays an important role in providing excellent particle identification capabilities, a fast and online trigger filter while aiding the track reconstruction capabilities. The calorimeter requirements are to provide a large acceptance for 100-MeV electrons and reach: 1) a time resolution better than 0.5 ns at 100 MeV; 2) an energy resolution O(10%) at 100 MeV; and 3) a position resolution of about 1 cm. The calorimeter consists of two disks, each one made of 674 pure CsI crystals readout by two large-area <inline-formula> <tex-math notation="LaTeX">2 \times 3 </tex-math></inline-formula> array of UV-extended silicon photomultipliers (Mu2e SiPMs) of <inline-formula> <tex-math notation="LaTeX">6\,\,\times6 </tex-math></inline-formula> mm 2 dimensions. A large-scale prototype has been constructed with 51 preproduction crystals readout by 102 Mu2e SiPMs. It has been tested at the beam test facility in Frascati, demonstrating satisfying results compared to the Mu2e requirements. At the moment of writing, the crystals production phase is halfway through the work, while the SiPM production has been completed. An overview of the characterization tests is also reported, together with a description of the final calorimeter design.
In this paper we present the time resolution measurements of the Lutetium–Yttrium Oxyorthosilicate (LYSO) calorimeter prototype for the Mu2e experiment. The measurements have been performed using the ...e− beam of the Beam Test Facility (BTF) in Frascati, Italy in the energy range from 100 to 400MeV. The calorimeter prototype consisted of twenty five 30×30×130mm3, LYSO crystals read out by 10×10mm2 Hamamatsu Avalanche Photodiodes (APDs). The energy dependence of the measured time resolution can be parametrized as σt(E)=a/E/GeV⊕b, with the stochastic and constant terms a=(51±1)ps and b=(10±4)ps, respectively. This corresponds to the time resolution of (162±4)ps at 100MeV.
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