777 research outputs found
Components Qualification for a Possible use in the Mu2e Calorimeter Waveform Digitizers
The Mu2e experiment at Fermilab searches for the charged flavor violating
conversion of a muon into an electron in the Coulomb field of a nucleus. The
detector consists of a straw tube tracker and a CSI crystal electromagnetic
calorimeter, both housed in a superconducting solenoid. Both the front-end and
the digital electronics, located inside the cryostat, will be operated in
vacuum under a 1 T magnetic field, having to sustain the high flux of neutrons
and ionizing particles coming from the muons stopping target. These harsh
experimental conditions make the design of the calorimeter waveform digitizer
quite challenging. All the selected commercial devices must be tested
individually and qualified for radiation hardness and operation in high
magnetic field. At the moment the expected particles flux and spectra at the
digitizers location are not completely simulated and we are using initial rough
estimates to select the components for the first prototype. We are gaining
experience in the qualification procedures using the selected components but
the choice will be frozen only when dose and neutron flux simulations will be
completed. The experimental results of the first qualification campaign are
presented.Comment: TWEPP 2016 - Topical Workshop on Electronics for Particle Physics,
26-30 September 2016, Karlsruhe Institute of Technology (KIT
Engagement With a Custom-Made Online System Designed to Support Undergraduate Work Placement
This paper describes an online system that was custom-made to allow BSc Optometry undergraduates to submit work electronically, while off-campus on work placement. One of the main aims of the system was to allow internal (college) supervisors to provide students with timely, formative feedback on work submitted. The system was piloted in academic year 2013-14 and an intrinsic case study was carried out to examine the engagement of the students, the external placement supervisors and the internal supervisors with the system. Engagement was gauged by examining all subjects’ interaction with the system and by asking them to complete a post placement questionnaire. The results showed a high level of engagement from both the students and external supervisors but a lower level of engagement from the internal supervisors, in particular with regard to the provision of formative feedback. Possible reasons for the different levels of engagement are discussed and changes to be made to the system for academic year 2014-15 (based on the findings of the case study) are outlined
Pre-Production and Quality Assurance of the Mu2e Calorimeter Silicon Photomultipliers
The Mu2e electromagnetic calorimeter has to provide precise information on
energy, time and position for 100 MeV electrons. It is composed of 1348
un-doped CsI crystals, each coupled to two large area Silicon Photomultipliers
(SiPMs). A modular and custom SiPM layout consisting of a 32 array of
66 mm UV-extended monolithic SiPMs has been developed to fulfill
the Mu2e calorimeter requirements and a pre-production of 150 prototypes has
been procured by three international firms (Hamamatsu, SensL and Advansid). A
detailed quality assurance process has been carried out on this first batch of
photosensors: the breakdown voltage, the gain, the quenching time, the dark
current and the Photon Detection Efficiency (PDE) have been determined for each
monolithic cell of each SiPMs array. One sample for each vendor has been
exposed to a neutron fluency up to 8.5~~10 1 MeV (Si) eq.
n/cm and a linear increase of the dark current up to tens of mA has been
observed. Others 5 samples for each vendor have undergone an accelerated aging
in order to verify a Mean Time To Failure (MTTF) higher than 10
hours.Comment: NDIP 2017 - New Developments In Photodetection, 3-7 July 2017, Tours
(France
Design, status and perspective of the Mu2e crystal calorimeter
The Mu2e experiment at Fermilab will search for the charged lepton flavor
violating process of neutrino-less coherent conversion in the field
of an aluminum nucleus. Mu2e will reach a single event sensitivity of about
that corresponds to four orders of magnitude improvements
with respect to the current best limit. The detector system consists of a straw
tube tracker and a crystal calorimeter made of undoped CsI coupled with Silicon
Photomultipliers. The calorimeter was designed to be operable in a harsh
environment where about 10 krad/year will be delivered in the hottest region
and work in presence of 1 T magnetic field. The calorimeter role is to perform
/e separation to suppress cosmic muons mimiking the signal, while
providing a high level trigger and a seeding the track search in the tracker.
In this paper we present the calorimeter design and the latest RD results.Comment: 4 pages, conference proceeding for a presentation held at TIPP'2017.
To be published on Springer Proceedings in Physic
The Mu2e undoped CsI crystal calorimeter
The Mu2e experiment at Fermilab will search for Charged Lepton Flavor
Violating conversion of a muon to an electron in an atomic field. The Mu2e
detector is composed of a tracker, an electromagnetic calorimeter and an
external system, surrounding the solenoid, to veto cosmic rays. The calorimeter
plays an important role to provide: a) excellent particle identification
capabilities; b) a fast trigger filter; c) an easier tracker track
reconstruction. Two disks, located downstream of the tracker, contain 674 pure
CsI crystals each. Each crystal is read out by two arrays of UV-extended SiPMs.
The choice of the crystals and SiPMs has been finalized after a thorough test
campaign. A first small scale prototype consisting of 51 crystals and 102 SiPM
arrays has been exposed to an electron beam at the BTF (Beam Test Facility) in
Frascati. Although the readout electronics were not the final, results show
that the current design is able to meet the timing and energy resolution
required by the Mu2e experiment.Comment: 6 pages, 8 figures, proceedings of the "Calorimetry for the high
energy frontier (CHEF17)" conference, 2-6 October 2017, Lyon, Franc
Quality Assurance on a custom SiPMs array for the Mu2e experiment
The Mu2e experiment at Fermilab will search for the coherent
conversion on aluminum atoms. The detector system consists of a straw tube
tracker and a crystal calorimeter. A pre-production of 150 Silicon
Photomultiplier arrays for the Mu2e calorimeter has been procured. A detailed
quality assur- ance has been carried out on each SiPM for the determination of
its own operation voltage, gain, dark current and PDE. The measurement of the
mean-time-to-failure for a small random sample of the pro-production group has
been also completed as well as the determination of the dark current increase
as a function of the ioninizing and non-ioninizing dose.Comment: 4 pages, 10 figures, conference proceeding for NSS-MIC 201
Elastic Scattering and Total Cross-Section in p+p reactions measured by the LHC Experiment TOTEM at sqrt(s) = 7 TeV
Proton-proton elastic scattering has been measured by the TOTEM experiment at
the CERN Large Hadron Collider at TeV in special runs with the
Roman Pot detectors placed as close to the outgoing beam as seven times the
transverse beam size. The differential cross-section measurements are reported
in the |t|-range of 0.36 to 2.5 GeV^2. Extending the range of data to low t
values from 0.02 to 0.33 GeV^2,and utilizing the luminosity measurements of
CMS, the total proton-proton cross section at sqrt(s) = 7 TeV is measured to be
(98.3 +- 0.2(stat) +- 2.8(syst)) mb.Comment: Proceedings of the XLI International Symposium on Multiparticle
Dynamics. Accepted for publication in Prog. Theor. Phy
Performance of the TOTEM Detectors at the LHC
The TOTEM Experiment is designed to measure the total proton-proton
cross-section with the luminosity-independent method and to study elastic and
diffractive pp scattering at the LHC. To achieve optimum forward coverage for
charged particles emitted by the pp collisions in the interaction point IP5,
two tracking telescopes, T1 and T2, are installed on each side of the IP in the
pseudorapidity region 3.1 < = |eta | < = 6.5, and special movable beam-pipe
insertions - called Roman Pots (RP) - are placed at distances of +- 147 m and
+- 220 m from IP5. This article describes in detail the working of the TOTEM
detector to produce physics results in the first three years of operation and
data taking at the LHC.Comment: 40 pages, 31 figures, submitted to Int. J. Mod. Phys.
WGEAWESS: Integrated Ecosystems Assessment of the Western European Shelf Seas
oral presentation abstractTraditionally, integrated ecosystem assessment (IEA) has been developed regionally using different strategies and tools, leading to problems of comparability and integration and even different assessments of status (e.g. GES) across shared boundaries. WGEAWESS undertakes IEA throughout the western European shelf seas to support ecosystem-based management (EBM) measures at the local, national, regional and EU levels. Relevant to key EU Directives (e.g. MSFD, WFD & CFP), IEA makes explicit links between human activities and ecosystem health, assessing the scale of impact and recovery, enabling targeted management and mitigation measures. Employing a combination of integrated trend analyses to generate time series of pressures and impacts, semi-quantitative methods to fill data gaps and inform future research effort, and reviewing and updating existing ecosystem models throughout the regions, WGEAWESS reviews and assesses patterns of human activities, their pressures, and ecosystem components to underpin the process.
WGEAWESS is developing plans to advance this work thought a large scale project that would use quantitative integrators of ecosystem functioning (indicators) in experimental platforms to assess and gain insight into pressure effects and proliferation, and to forecast futures under various management scenarios. Case study investigations, with priorities specified via direct engagement with relevant stakeholders, would enable management decisions to be based on regional and/or local priorities, and ensuring recognition of the social context. Finally, a guide on translating IEA into advice for EBM and demonstrating its practical use in informing specific issues regarding the management of ecosystem services would be produced, along with an interactive web-based ‘living’ tool which will and provide a key resource for researchers, decision-makers and the general public alike
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