High purity 100 GeV electron identification with synchrotron radiation

• Published in: Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment Vol. 866; pp. 196 - 201
• Main Authors: Depero, E., Banerjee, D., Burtsev, V., Chumakov, A., Cooke, D., Dermenev, A.V., Donskov, S.V., Dubinin, F., Dusaev, R.R., Emmenegger, S., Fabich, A., Frolov, V.N., Gardikiotis, A., Gninenko, S.N., Hösgen, M., Karneyeu, A.E., Ketzer, B., Kirsanov, M.M., Konorov, I.V., Kramarenko, V.A., Kuleshov, S.V., Lyubovitskij, V.E., Lysan, V., Matveev, V.A., Mikhailov, Yu.V., Myalkovskiy, V.V., Peshekhonov, V.D., Peshekhonov, D.V., Polyakov, V.A., Radics, B., Rubbia, A., Samoylenko, V.D., Tikhomirov, V.O., Tlisov, D.A., Toropin, A.N., Vasilishin, B., Arenas, G. Vasquez, Ulloa, P., Crivelli, P.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 11.09.2017
• Subjects: Hadron rejection; High energy electron tagging; Synchrotron detector; Synchrotron detector; High energy electron tagging; Hadron rejection
• ISSN: 0168-9002; 1872-9576
• DOI: 10.1016/j.nima.2017.05.028

In high energy experiments such as active beam dump searches for rare decays and missing energy events, the beam purity is a crucial parameter. In this paper we present a technique to reject heavy charged particle contamination in the 100 GeV electron beam of the H4 beam line at CERN SPS. The method is based on the detection with BGO scintillators of the synchrotron radiation emitted by the electrons passing through a bending dipole magnet. A 100 GeV π− beam is used to test the method in the NA64 experiment resulting in a suppression factor of 10−5 while the efficiency for electron detection is ∼95%. The spectra and the rejection factors are in very good agreement with the Monte Carlo simulation. The reported suppression factors are significantly better than previously achieved.