248 research outputs found
100ps time resolution with thin silicon pixel detectors and a SiGe HBT amplifier
A 100um thick silicon detector with 1mm2 pad readout optimized for
sub-nanosecond time resolution has been developed and tested. Coupled to a
purposely developed amplifier based on SiGe HBT technology, this detector was
characterized at the H8 beam line at the CERN SPS. An excellent time resolution
of (106+-1)ps for silicon detectors was measured with minimum ionizing
particles
A monolithic ASIC demonstrator for the Thin Time-of-Flight PET scanner
Time-of-flight measurement is an important advancement in PET scanners to
improve image reconstruction with a lower delivered radiation dose. This
article describes the monolithic ASIC for the TT-PET project, a novel idea for
a high-precision PET scanner for small animals. The chip uses a SiGe Bi-CMOS
process for timing measurements, integrating a fully-depleted pixel matrix with
a low-power BJT-based front-end per channel, integrated on the same 100 thick die. The target timing resolution is 30 ps RMS for electrons from the
conversion of 511 keV photons. A novel synchronization scheme using a
patent-pending TDC is used to allow the synchronization of 1.6 million channels
across almost 2000 different chips at picosecond-level. A full-featured
demonstrator chip with a 3x10 matrix of 500x500 pixels was
produced to validate each block. Its design and experimental results are
presented here
Arctic ocean chronology confirmed by accelerator 14C dating
The role of the Arctic Ocean in Earth's climatic and oceanographic development is significant but has become controversial because of disagreements concerning a reliable Arctic chronology. The first Arctic Ocean chronology based on U-Th and 14C data was in agreement with magnetostratigraphy developed later but these data have been challenged by recent amino acid diagenesis dates. New accelerator 14C data support the earlier U-Th-magnetostratigraphic dates and confirm the reliability of the established Arctic Ocean chronology
Characterization of the demonstrator of the fast silicon monolithic ASIC for the TT-PET project
The TT-PET collaboration is developing a small animal TOF-PET scanner based
on monolithic silicon pixel sensors in SiGe BiCMOS technology. The demonstrator
chip, a small-scale version of the final detector ASIC, consists of a 3 x 10
pixel matrix integrated with the front-end, a 50 ps binning TDC and read out
logic. The chip, thinned down to 100 {\mu}m and backside metallized, was
operated at a voltage of 180 V. The tests on a beam line of minimum ionizing
particles show a detection efficiency greater than 99.9 % and a time resolution
down to 110 ps
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