Channeling of Relativistic Electrons in Half-Wave Silicon Crystal and Corresponding Radiation

The new experiments on channeling of 255 MeV in a 0.7 ?m silicon half-wavelength crystal were performed at SAGA LS facility. Both experimental and simulated electron angular distribution after the crystal and corresponding radiation spectra reveal the number of peculiarities

Mass dependence of spectral and angular distributions of Cherenkov radiation from relativistic isotopes in solid radiators and its possible application as mass selector

The first proof of principle experiment with a prototype of a Time-of-Flight (TOF) - Cherenkov detector of relativistic heavy ions (RHI) exploiting a liquid Iodine Naphthalene radiator has been performed at Cave C at GSI (Darmstadt, Germany). A conceptual design for a liquid Cherenkov detector was proposed as a prototype for the future TOF measurements at the SuperFRS by detection of total number of Cherenkov photons. The ionization energy loss of RHI in a liquid radiator decreases only slightly this number, while in a solid radiator changes sufficiently not the total number of ChR photons, but ChR angular and spectral distributions. By means of computer simulations, we showed that these distributions are very sensitive to the isotope mass, due to different stopping powers of isotopes with initial equal relativistic factors. The results of simulations for light (Li, Be) and heavy (Xe) isotopes at 500-1000 MeV/u are presented indicating the possibility to use the isotopic effect in ChR of RHI as the mass selector

Observation of sub-GeV electrons mirrored by ultrathin crystalline Si

Detailed experimental studies are performed on the mirroring effect for 255-MeV electrons channeled through a 0.74-μm-thick Si crystal at the injector linac of the SAGA-LS facility. For the planar channeling alignment, deflection of the beam by 0.45 mrad is observed with 29% efficiency. The effect is explained by computer simulations as a sequence of trajectories of planar-channeled relativistic electrons in an attractive one-dimensional periodic potential of crystallographic planes. Possible applications as a beam splitter are proposed

Nätkränkningar : Interventioner och relationer i skolan

This study is a systematic literature review over 12 peer reviewed articles regarding the topiccyberbullying. The purpose of this study is to summarise and critically discuss different interventions and preventions used to tackle cyberbullying in school environments.Interventions and preventions will be analysed from a relational perspective. The articles are sorted and discussed in four relevant categories. These are: Netiquette, building relationships, Learning through role models, antibullying programs. The study found that the foundation of most successful interventions against cyberbullying is healthy relationships between students and school staff. The result showed that based on meaningful relationships, successful interventions and preventions can be formed and used in school. It is important to acknowledge that not a single intervention can solve a complex problem like cyberbullying, but instead there is a need for a combination of different interventions and more knowledge about the phenomena cyberbullying

Charge states and energy loss of 300 MeV/u U73+^{73+} ions channeled in a silicon crystal

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