R3B ASIC User Manual
1 Overview
R3B (Reaction studies with Relativistic Radioactive Beams) is a fixed-target detector system with high
efficiency, acceptance, and resolution for kinematically complete measurements of reactions with
high-energy radioactive beams. It will be located at the focal plane of the high-energy branch of the
Super-FRS (Fragment Separator), which is a magnetic spectrometer. This experiment forms part of
NUSTAR (Nuclear Structure Astrophysics and Reactions) and will be installed at FAIR (Facility for
Antiproton and Ion Research) in Germany.
Detectors will track and identify a radioactive beam onto and out from a reaction target, Light
charged particles and gamma rays from the target region will be measured by the target recoil
detector. This detector surrounds the target volume and consists of two main elements: the Si
tracker and the calorimeter. The Si tracker is a three-layer silicon micro-vertex tracker, providing
precise tracking and vertex determination as well as energy and multiplicity measurement.
The R3B ASIC is intended for reading out, processing and digitising signals generated by ionising
particles passing through the silicon strip detector. These signals are comprised of either electrons or
holes depending on the polarity of the detector.
A block diagram of the ASIC is shown in figure 1.
I 2 C Interface
Control Registers
128
Channels
Analogue
Multiplexer
12 bit
ADC
Data
Buffer
Signal
Preamplifier Shaper
Peak Hold
Calibration
Mask
Gain
Amplifier
Comparator
Channel Control
Logic
Chip Control Logic
Gain
Amplifier
Comparator
Time Stamp
Counter
128 bit OR
Trigger
Calibration Calibration
Controls Voltage Level
Energy
Threshold
Time Stamp
Threshold
Time Stamp
Clock
Figure 1 : Block Diagram of the R3B ASIC
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