Payload radiation overview: https://docs.google.com/document/d/1uMhZbrjy4h7P3S4hgvYHxCAvWjgHozcVUgSRDQH5D5s/edit?usp=sharing
launch canada design proposal https://docs.google.com/document/d/1O7Zn6XXuKUzf7-EnrcJN0tukMsXGqb2XmS91orYVu7I/edit?usp=sharing irec final report (starting p 40) https://docs.google.com/document/d/1KT3We5JVC4YxGNyok-100HUN1bcSWUTdOZXlH0dCf8o/edit?usp=sharing
Overview*********************************** Measuring the radiation detection properties of BNNTs and Metal Oxides. Radiaiton detection Scintillator - Lights up when exposed to ionizing radiation SiPM - Silicon photomultiplier, sensor that counts the number of photons it sees. Scintillator generates light, SiPM generates a current pulse proportional to the magnitude of radiation. In order to detect and log that current pulse on an MCU we need to 1. Convert the current signal to voltage 2. Amplify the voltage pulse to increase difference between singal and noise and make it easier to detect and losses negligible. 3. Extend the length of the signal so the MCU has time to made an ADC conversion. Detector Circuit Topology: 1. Transimpdance amplifier converts current signal to voltage, amplifies it in a way to reduce the signal to noise ratio. The main purpose of this board is to fine-tune the resistor and capacitor values to optimize the gain on this amplifier. 2. Filter stage to eliminaty high and low frequency noise 3. Second stage amplfication 4. Peak detector to extend signal 5. Voltage follower to ensure signal sampling does not interfere with the peak detector circuit. Data logging: After the second stage amplificaiton, the signal line is sent to both the peak detector and a comparator. The comparator compares the signal to a set baseline voltage value, and if the signal exceeds this amount, it generates an interrupt. This interrupt is used to tell the MCU when to take an ADC sample from the peak detector line.
Data logging: After the second stage amplificaiton, the signal line is sent to both the peak detector and a comparator. The comparator compares the signal to a set baseline voltage value, and if the signal exceeds this amount, it generates an interrupt. This interrupt is used to tell the MCU when to take an ADC sample from the peak detector line. Voltage supply: Because the detector circuit is sensative anlaog circuitry, it runs off a seperate 4.7V line from an LDO. The LDO cleans the 5V line to ensure low-noise, as well as seperates the detector circuit supplies from any noise generated by the switching supplies. The SiPM requires 36V to operate. This is achieved with a voltage booster paried with an LDO to make sure the supply voltage is clean. The detector_support circuit is configured to support both a test connection (5V and 12V from the bench top supply) as well as battery connections for use in lab testing.