Synchrotron Light Research Institute (SLRI) has successfully constructed a new experimental station, a Beam Test Facility (BTF), to the current SLRI accelerator complex. SLRI-BTF is capable of ...producing electron test beams with the number of electrons ranging from a few to millions of electrons per spill and with tunable energy from 40 MeV up to 1.2 GeV. The required intensity and energy of the test beam are obtained using a combination of a metal target to reduce high-intensity primary beam and a synchrotron booster to accelerate secondary beam to desired energy. The repetition rate of the test beam is up to 0.5 Hz depending on the selected energy and the pulse width is 90 ns. SLRI-BTF targets to service electron test beams with defined intensity and energy for testing and calibration of high-energy particle detectors as well as other beam diagnostic instrumentations. In commissioning, a pixel sensor telescope was employed as a detector to measure the number of electrons and as a preparation to investigate efficiency of mono active pixel sensors. The results confirm production of the low multiplicity of high-energy electrons at SLRI-BTF and the efficiency of a test pixel sensor is successfully calculated.
A novel approach for designing the next generation of vertex detectors foresees to employ wafer-scale sensors that can be bent to truly cylindrical geometries after thinning them to thicknesses of ...20-40\(\mu\)m. To solidify this concept, the feasibility of operating bent MAPS was demonstrated using 1.5\(\times\)3cm ALPIDE chips. Already with their thickness of 50\(\mu\)m, they can be successfully bent to radii of about 2cm without any signs of mechanical or electrical damage. During a subsequent characterisation using a 5.4GeV electron beam, it was further confirmed that they preserve their full electrical functionality as well as particle detection performance. In this article, the bending procedure and the setup used for characterisation are detailed. Furthermore, the analysis of the beam test, including the measurement of the detection efficiency as a function of beam position and local inclination angle, is discussed. The results show that the sensors maintain their excellent performance after bending to radii of 2cm, with detection efficiencies above 99.9% at typical operating conditions, paving the way towards a new class of detectors with unprecedented low material budget and ideal geometrical properties.
