Focusing of 180 GeV/c pions from a point-like source into a parallel beam by a bent silicon crystal

• Published in: Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms Beam interactions with materials and atoms, 2019-05, Vol.446, p.15-18
• Main Authors: Scandale, W., Arduini, G., Cerutti, F., Garattini, M., Gilardoni, S., Lechner, A., Losito, R., Masi, A., Mirarchi, D., Montesano, S., Natochii, A., Redaelli, S., Rossi, R., Smirnov, G., Breton, D., Burmistrov, L., Chaumat, V., Dubos, S., Maalmi, J., Puill, V., Stocchi, A., Bagli, E., Bandiera, L., Romagnoni, M., Guidi, V., Mazzolari, A., Murtas, F., Addesa, F., Cavoto, G., Iacoangeli, F., Galluccio, F., Afonin, A.G., Chesnokov, Yu.A., Durum, A.A., Maisheev, V.A., Sandomirskiy, Yu.E., Yanovich, A.A., Kovalenko, A.D., Taratin, A.M., Denisov, A.S., Gavrikov, Yu.A., Ivanov, Yu.M., Lapina, L.P., Malyarenko, L.G., Skorobogatov, V.V., Auzinger, G., Borg, J., James, T., Hall, G., Pesaresi, M.
• Format: Article
• Language: English
• Subjects: Accelerator Physics; Beam focusing; Crystal channeling; Nuclear Experiment; Physics
• ISSN: 0168-583X; 1872-9584; 1872-9584; 0168-583X
• DOI: 10.1016/j.nimb.2019.03.024

At large accelerators, bent crystals are employed to deflect weakly divergent proton beams at the stages of extraction and collimation. We demonstrate that a divergent particle beam may be efficiently deflected using a crystal with a focusing entry face. A 180 GeV/c pion beam with divergence near 0.060 mrad, which exceeds the Lindhard angle by a factor of 4, has been experimentally deflected by 0.25 mrad with efficiency near 22%. The proposed focusing crystal may serve as an element of a novel particle optics for secondary-particle beams in the TeV energy region.