Transition edge sensor-based detector:from X-ray to γ-ray

A transition edge sensor(TES)is extremely sensitive to changes in temperature,and combined with a high-Z metal of a certain thickness,it can realize high-energy resolution measurements of particles such as X-rays.X-rays with energies below 10 keV have a weak penetrating ability,hence,only gold or bismuth of a few micrometers in thickness can guarantee a quantum efficiency higher than 70%.Therefore,the entire structure of the TES X-ray detector in this energy range can be realized using a microfabrication process.However,for X-rays or γ-rays from 10 keV to 200 keV,submillimeter absorber layers are required,which cannot be realized using the microfabrication process.This paper first briefly introduces a set of TES X-ray detectors and their auxiliary systems,and then focuses on the introduction of the TES γ-ray detector with an absorber based on a submillimeter lead-tin alloy sphere.The detector achieved a quantum efficiency above 70% near 100 keV and an energy resolution of approximately 161.5 eV at 59.5 keV.

Design of a MAPS readout electronics prototype for BESIII inner tracker

Background The spatial resolution and the reconstruction efficiency of the main drift chamber of the Beijing Spectrometer III has degraded aftermore than nine years of operation.An improved new inner drift chamber has been constructed to replace the old chamber in case of the radiation damage.Amonolithic active pixel sensor(MAPS)based detector prototype is selected as one of the prototype schemes for the inner chamber upgrade.Purpose Design a set of MAPS readout electronics system for the inner drift chamber upgrade.This system can verify the function and performance of the selected MAPS chip and discover the matters needing attention when designing large-scale detectors.Methods The electronics system design is composed of three parts.The first part is flexible printed circuit boards(PCBs)assembled with the MAPS chips.The second part is digital readout boards,which are connected to the flexible PCBs via FPGA mezzanine card cables.The digital readout board realizes the configuration of the MAPS chip register,receives and processes the data output by the MAPS chip,and transfers the processed data to the DAQ device.The third part includes a readout control board and two fan-out boards that used to separately fan out the trigger signal and the start signal to all the digital readout boards.Results and conclusion AMAPS readout electronics system consisting of five MAPS based detector prototypes is designed.The system can work stably under the electron beam experimental conditions with a frequency up to 2 kHz and energy ranging from 1 to 5 GeV.The system detection efficiency of the electron beam is∼95%,and the spatial resolution is∼5.3μm at electron energies of 1 GeV.The design of the electronics system meets the requirements for verifying the performance of the MAPS chips and the technical feasibility of the detector structure.