Order of Magnitude Beam Current Improvement in Compact Cyclotrons

There is great need for high intensity proton beams from compact particle accelerators in particle physics, medical isotope production, and materials- and energy-research. To this end, the DAE$\delta$ALUS/IsoDAR collaboration is developing a compact isochronous cyclotron that will be able to deliver 10 mA of protons - an order of magnitude higher than on-market compact cyclotrons and a factor four higher than research machines. For the first time, vortex motion is incorporated in the design of a cyclotron, which is key to reaching high extracted beam current. We present high-fidelity simulations of the acceleration of a 5 mA H$_2^+$ beam (equivalent to 10 mA of protons) in this cyclotron, using the particle-in-cell code OPAL, demonstrating the feasibility of constructing this machine. The simulations are based on the latest cyclotron design and through them, we show that sufficient turn separation between the $(\mathrm{N}-1)^{th}$ and $\mathrm{N}^{th}$ turn can be achieved even with initially mismatched beams by careful placement of collimators to scrape away halo particles before the beam energy has reached 1.5 MeV/amu. We describe in detail the process for placement of electrostatic extraction channels. Beam losses on the septa of these channels stay below 50 W with beam quality sufficient for transport to the target. Furthermore, we present an uncertainty quantification of select beam input parameters using machine learning, showing the robustness of the design.Comment: To be submitted to PR

First commissioning results of the multicusp ion source at MIT (MIST-1) for H2+

IsoDAR is an experiment under development to search for sterile neutrinos using the isotope Decay-At-Rest (DAR) production mechanism, where protons impinging on 9Be create neutrons which capture on 7Li which then beta-decays producing ve. As this will be an isotropic source of ve, the primary driver current must be large (10 mA cw) for IsoDAR to have sufficient statistics to be conclusive within 5 years of running. H2+ was chosen as primary ion to overcome some of the space-charge limitations during low energy beam transport and injection into a compact cyclotron. The H2+ will be stripped into protons before the target. At MIT, a multicusp ion source (MIST-1) was designed and built to produce a high intensity beam with a high H2+ fraction. MIST-1 is now operational at the Plasma Science and Fusion Center (PSFC) at MIT and under commissioning.National Science Foundation (U.S.). (Grant PHY-1505858)Bose Foundatio

Contemporary research in minoritized and diaspora languages of Europe

This volume provides a collection of research reports on multilingualism and language contact ranging from Romance, to Germanic, Greco and Slavic languages in situations of contact and diaspora. Most of the contributions are empirically-oriented studies presenting first-hand data based on original fieldwork, and a few focus directly on the methodological issues in such research. Owing to the multifaceted nature of contact and diaspora phenomena (e.g. the intrinsic transnational essence of contact and diaspora, and the associated interplay between majority and minoritized languages and multilingual practices in different contact settings, contact-induced language change, and issues relating to convergence) the disciplinary scope is broad, and includes ethnography, qualitative and quantitative sociolinguistics, formal linguistics, descriptive linguistics, contact linguistics, historical linguistics, and language acquisition. Case studies are drawn from Italo-Romance varieties in the Americas, Spanish-Nahuatl contact, Castellano Andino, Greko/Griko in Southern Italy, Yiddish in Anglophone communities, Frisian in the Netherlands, Wymysiöryś in Poland, Sorbian in Germany, and Pomeranian and Zeelandic Flemish in Brazil

Contemporary research in minoritized and diaspora languages of Europe

This volume provides a collection of research reports on multilingualism and language contact ranging from Romance, to Germanic, Greco and Slavic languages in situations of contact and diaspora. Most of the contributions are empirically-oriented studies presenting first-hand data based on original fieldwork, and a few focus directly on the methodological issues in such research. Owing to the multifaceted nature of contact and diaspora phenomena (e.g. the intrinsic transnational essence of contact and diaspora, and the associated interplay between majority and minoritized languages and multilingual practices in different contact settings, contact-induced language change, and issues relating to convergence) the disciplinary scope is broad, and includes ethnography, qualitative and quantitative sociolinguistics, formal linguistics, descriptive linguistics, contact linguistics, historical linguistics, and language acquisition. Case studies are drawn from Italo-Romance varieties in the Americas, Spanish-Nahuatl contact, Castellano Andino, Greko/Griko in Southern Italy, Yiddish in Anglophone communities, Frisian in the Netherlands, Wymysiöryś in Poland, Sorbian in Germany, and Pomeranian and Zeelandic Flemish in Brazil

Contemporary research in minoritized and diaspora languages of Europe

This volume provides a collection of research reports on multilingualism and language contact ranging from Romance, to Germanic, Greco and Slavic languages in situations of contact and diaspora. Most of the contributions are empirically-oriented studies presenting first-hand data based on original fieldwork, and a few focus directly on the methodological issues in such research. Owing to the multifaceted nature of contact and diaspora phenomena (e.g. the intrinsic transnational essence of contact and diaspora, and the associated interplay between majority and minoritized languages and multilingual practices in different contact settings, contact-induced language change, and issues relating to convergence) the disciplinary scope is broad, and includes ethnography, qualitative and quantitative sociolinguistics, formal linguistics, descriptive linguistics, contact linguistics, historical linguistics, and language acquisition. Case studies are drawn from Italo-Romance varieties in the Americas, Spanish-Nahuatl contact, Castellano Andino, Greko/Griko in Southern Italy, Yiddish in Anglophone communities, Frisian in the Netherlands, Wymysiöryś in Poland, Sorbian in Germany, and Pomeranian and Zeelandic Flemish in Brazil