adc/mca module with pc interface (rs232/rs485/usb/ethernet)
DESCRIPTION
ADC/MCA Module With PC Interface (RS232/RS485/USB/Ethernet). Georgi Georgiev , Ivaylo Peev Institute For Nuclear Research And Nuclear Energy Bulgarian Academy Of Sciences. The Goal. Building a combination of fast ADC with low differential non-linearity (DNL) and multi-channel analyzer. - PowerPoint PPT PresentationTRANSCRIPT
Georgi Georgiev, Ivaylo Peev - Bulgarian Academy Of Sciences
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ADC/MCA Module With PC Interface(RS232/RS485/USB/Ethernet)
Georgi Georgiev, Ivaylo Peev
Institute For Nuclear Research And Nuclear Energy
Bulgarian Academy Of Sciences
Georgi Georgiev, Ivaylo Peev - Bulgarian Academy Of Sciences
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The Goal
• Building a combination of fast ADC with low differential non-linearity (DNL) and multi-channel analyzer.
• Compact size.
• Operate multiple ADC/MCA modules by one computer.
• Remote operation and management over TCP/IP.
Georgi Georgiev, Ivaylo Peev - Bulgarian Academy Of Sciences
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The Solution
• Using Gatti correction proposed by C. Cottini, E.Gatti and V.Svelto in 1963.
• Involving modern technology.
– Fast A/D and D/A converters.
– Programmable logic devices.
– “Smart” approach.
Georgi Georgiev, Ivaylo Peev - Bulgarian Academy Of Sciences
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Implementation
ADC with S/HADC/MCA
Control
Logic
&
RAM
FPGAPrecise DAC
Input
stagesInput
Processor
PC Interface
(USB/Ethernet)
Peak
Detector
Pile Up
Gate
Electronic
Control DAC
Georgi Georgiev, Ivaylo Peev - Bulgarian Academy Of Sciences
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Main Points
• Precise peak detector used for accurate start of measurement process.
• Fixed dead time differential input ADC with S/H.
• Only one precise voltage reference source is used in order to minimize possible errors.
• Predefined spectra capture time (Live time).
Georgi Georgiev, Ivaylo Peev - Bulgarian Academy Of Sciences
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Main Points
• High precision DAC used to shift the measurement point on each event.
• 4-channel DAC used to control LLD, ULD and other parameters.
• Fully buffered spectra capture and transfer.
• Micro-controller manages the communication channel and handles the protocol.
• Optically isolated interface (RS232/485/USB).
Georgi Georgiev, Ivaylo Peev - Bulgarian Academy Of Sciences
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The device
Georgi Georgiev, Ivaylo Peev - Bulgarian Academy Of Sciences
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Features and performance
• Total processing time of 640ns.
• No added dead time for pulses with 125ns shaping time.
• 1k, 2k and 4k channel spectra captured.
• Digital control of LLD, ULD and other front-end parameters.
Georgi Georgiev, Ivaylo Peev - Bulgarian Academy Of Sciences
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Software
Georgi Georgiev, Ivaylo Peev - Bulgarian Academy Of Sciences
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Sample results25.19 KeV
8.04 KeV
Georgi Georgiev, Ivaylo Peev - Bulgarian Academy Of Sciences
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Possible signal sources
• SDD detectors.
• NaI(Tl) scintillators.
• Conventional detectors.
Georgi Georgiev, Ivaylo Peev - Bulgarian Academy Of Sciences
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Applications
• Fast on-line analysis.
• Analysis using high intensity sources.