2015, Abramowicz, H., Abusleme, A., Afanaciev, K., Aguilar, J., Alvarez, E., Avila, D., Benhammou, Y., Bortko, L., Borysov, O., Bergholz, M., Bozovic-Jelisavcic, I., Castro, E., Chelkov, G., Coca, C., Daniluk, W., Dumitru, L., Elsener, K., Fadeyev, V., Firlej, M., Firu, E., Fiutowski, T., Ghenescu, V., Gostkin, M., Henschel, H., Idzik, M., Ishikawa, A., Kananov, S., Kollowa, S., Kotov, S., Kotula, J., Kozhevnikov, D., Kruchonok, V., Krupa, B., Kulis, Sz., Lange, W., Lesiak, T., Levy, A., Levy, I., Lohmann, W., Lukic, S., Milke, C., Moron, J., Moszczynski, A., Neagu, A.T., Novgorodova, O., Oliwa, K., Orlandea, M., Pandurovic, M., Pawlik, B., Preda, T., Przyborowski, D., Rosenblat, O., Sailer, A., Sato, Y., Schumm, B., Schuwalow, S., Smiljanic, I., Smolyanskiy, P., Swientek, K., Teodorescu, E., Terlecki, P., Wierba, W., Wojton, T., Yamaguchi, S., Yamamoto, H., Zawiejski, L., Zgura, I.S., Zhemchugov, A.

Detector-plane prototypes of the very forward calorimetry of a future detector at an e+e− collider have been built and their performance was measured in an electron beam. The detector plane comprises silicon or GaAs pad sensors, dedicated front-end and ADC ASICs, and an FPGA for data concentration. Measurements of the signal-to-noise ratio and the response as a function of the position of the sensor are presented. A deconvolution method is successfully applied, and a comparison of the measured shower shape as a function of the absorber depth with a Monte-Carlo simulation is given.