https://doi.org/10.1051/epjconf/202532000008
Test-beam measurements of instrumented sensor planes for a highly compact and granular electromagnetic calorimeter
IFIC, CSIC and Universitat de València, C/ Catedràtic José Beltrán Martínez 2, 46980 Paterna, Spain
* e-mail: melissa.almanza@ific.uv.es
Published online: 7 March 2025
The LUXE experiment is designed to explore the strong-field QED regime in interactions of high-energy electrons from the European XFEL in a powerful laser field. One of the crucial aims of this experiment is to measure the production of electron-positron pairs as a function of the laser field strength where non-perturbative effects are expected to kick in above the Schwinger limit. For the measurements of positron energy and multiplicity spectra, a tracker and an electromagnetic calorimeter are foreseen. The expected number of positrons varies over ten orders of magnitude and has to be measured over a widely spread low-energy background. To overcome these challenges, a compact and finely segmented calorimeter is proposed. The concept of a sandwich calorimeter made of tungsten absorber plates interspersed with thin sensor planes is developed. The sensor planes comprise a silicon pad sensor, flexible Kapton printed circuit planes for bias voltage supply and signal transport to the sensor edge, all embedded in a carbon fiber support. The thickness of a sensor plane is less than 1 mm. A dedicated readout is developed comprising front-end ASICs in 130 nm technology and FPGAs to orchestrate the ASICs and perform data pre-processing. As an alternative, GaAs sensors are considered with integrated readout strips on the sensor. Prototypes of both sensor planes are studied in an electron beam of 5 GeV. Results will be presented on the homogeneity of the response and edge effects.
© The Authors, published by EDP Sciences, 2025
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