3,056 research outputs found
Impact of the LHC beam abort kicker prefire on high luminosity insertion and CMS detector performance
Wire scanners in low energy accelerators
Fast wire scanners are today considered as part of standard instrumentation
in high energy synchrotrons. The extension of their use to synchrotrons working
at lower energies, where Coulomb scattering can be important and the transverse
beam size is large, introduces new complications considering beam heating of
the wire, composition of the secondary particle shower and geometrical
consideration in the detection set-up. A major problem in treating these
effects is that the creation of secondaries in a thin carbon wire by a
energetic primary beam is difficult to describe in an analytical way. We are
here presenting new results from a full Monte Carlo simulation of this process
yielding information on heat deposited in the wire, particle type and energy
spectrum of secondaries and angular dependence as a function of primary beam
energy. The results are used to derive limits for the use of wire scanners in
low energy accelerators.Comment: 20 pages, 8 Postscript figures, uses elsart.cl
Radiation Testing of Electronics for the CMS Endcap Muon System
The electronics used in the data readout and triggering system for the
Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC)
particle accelerator at CERN are exposed to high radiation levels. This
radiation can cause permanent damage to the electronic circuitry, as well as
temporary effects such as data corruption induced by Single Event Upsets. Once
the High Luminosity LHC (HL-LHC) accelerator upgrades are completed it will
have five times higher instantaneous luminosity than LHC, allowing for
detection of rare physics processes, new particles and interactions. Tests have
been performed to determine the effects of radiation on the electronic
components to be used for the Endcap Muon electronics project currently being
designed for installation in the CMS experiment in 2013. During these tests the
digital components on the test boards were operating with active data readout
while being irradiated with 55 MeV protons. In reactor tests, components were
exposed to 30 years equivalent levels of neutron radiation expected at the
HL-LHC. The highest total ionizing dose (TID) for the muon system is expected
at the inner-most portion of the CMS detector, with 8900 rad over ten years.
Our results show that Commercial Off-The-Shelf (COTS) components selected for
the new electronics will operate reliably in the CMS radiation environment
Design, Implementation and First Measurements with the Medipix Neutron Camera in CMS
The Medipix detector is the first device dedicated to measuring mixed-field
radiation in the CMS cavern and able to distinguish between different particle
types. Medipix2-MXR chips bump bonded to silicon sensors with various neutron
conversion layers developed by the IEAP CTU in Prague were successfully
installed for the 2008 LHC start-up in the CMS experimental and services
caverns to measure the flux of various particle types, in particular neutrons.
They have operated almost continuously during the 2010 run period, and the
results shown here are from the proton run between the beginning of July and
the end of October 2010. Clear signals are seen and different particle types
have been observed during regular LHC luminosity running, and an agreement in
the measured flux rate is found with the simulations. These initial results are
promising, and indicate that these devices have the potential for further and
future LHC and high energy physics applications as radiation monitoring devices
for mixed field environments, including neutron flux monitoring. Further
extensions are foreseen in the near future to increase the performance of the
detector and its coverage for monitoring in CMS.Comment: 15 pages, 16 figures, submitted to JINS
Pinning Enhancement by Heterovalent Substitution in YREBaCuO
The intragrain pinning in high- superconductor compounds
YREBaCuO with low concentration of RE
(La, Ce, Pr) was investigated. Magnetic and transport measurements reveal that
the pinning is maximal for the concentration of heterovalent RE such that the
average distance between the impurity ions in the plane of rare-earth elements
close to the diameter of Abrikosov vortices in YBCO.Comment: 11 pages, 6 figures, will be published in SUS
Luotanko vai enkö luota? Nuorten luottamus sosiaalisessa mediassa leviävään informaatioon ja siihen liittyviä tekijöitä.
The increasing role that social media plays as a source of news and information has both positive and negative effects from the viewpoint of democratic societies. As sharing information on social media is easy, it has also become easier to spread false information. False news, which can render manipulation of people’s views and thoughts remarkably easy, can be extremely challenging to detect. We approached youngsters’ trust in social media content as a potential risk factor; trust can reduce uncertainty and suspicion of information and thus predict the spread of disinformation and conspiracy theories. This may have negative effects on societal security. We aimed to examine what factors explain Finnish youngsters’ (15–19 years) trust in news and information in social media. The analysis was based on a survey (N=800) collected in 2019– 2020. Using regression analysis we found four factors that were positively associated with youngsters’ trust in news and information in social media; trust in traditional media, daily use of social media, following social media influencers, and the belief that approval ratings predict the trustworthiness of news. In addition, the belief that social media gives a distorted view of other people’s lives was negatively connected to trust in news and information. From a national security perspective, youngsters’ social media use is often harmless. However, as their identities and worldviews are still developing, they may act as a target group for information campaigns which aim to undermine the stability of society and disrupt national security. Therefore, it is crucial to understand more about youngsters’ trust in social media content and their ability to detect false information
Manufacture of Bi-cuprate thin films on MgO single crystal substrates by chemical solution deposition
Bi2Sr2CaCu2O8 thin films have been deposited on MgO single crystal substrates by spin-coating a solution based on 2-ethylhexanoate precursors dissolved in xylene. Pyrolysis takes place between 200 degrees C and 450 degrees C and is accompanied by the release of 2-ethylhexanoic acid, CO2 and H2O vapour. Highly c-axis oriented Bi2Sr2CaCu2O8 as well as Er-or Ho-doped Bi2Sr2(Ca, Ln)Cu2O8 (Ln = Er, Ho) films were obtained after heat treatment at 840 degrees C in air
- …