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a. MOSSBAUER E.M. VELOCITY TRANSDUCER (TYPE: MT 170)
• MT 170 is designed based on Kankeliet type of design
• Two end drive with velocities ranging upto +/-25 mm/sec
• It is highly stable, rugged with excellent linearity (+/- 1 channel) and uses a two end Phosphor Bronze springs for suspension
• Line width better than <0.3.
• l Dimensions: 87 Dx 210 L in mm
l A 4BA threading is provided on both the ends for source fixing
Introduction
Mossbauer E.M. Velocity Transducer MT170 manufactured & supplied by Nucleonix Systems is based on Kankeliet type of design. In this two ring magnets are placed apart by approx. 120 mm & coupled by soft-iron rings & aluminum spacers. There are two coils (a) Drive coil & (b) Pick-up coil wound on bakelite bobbins and supported by a treaded aluminum rod & bobbins are separated by a gap of approx. 120 mm, just to ensure that each coil cuts the magnetic field from the respective ring magnets. This axial rod with bobbins with coils wound are supported & suspended at the two ends with phosphor bronze springs.
To one end of this treaded rod, Mossbauer source is fixed.
This velocity transducer is driven by drive current from the Mossbauer drive unit MD552 in constant acceleration mode.
Error output signal from the pick-up coil of the transducer is fed in, out of phase with the drive signal to correct for any non-linearity.
Important Specifications
• Velocity range : ± 25 mm/sec
• Drive Coil : 500 turn, 35 gauge
# Impedance : 12 Ohms
• Pick-up Coil : 1600 turns, 45 gauge
# Impedance : 480 Ohms
• Spacing between Bobbins :122.5mm
• Ring Magnet sizes : 72 dia x 16mm wide 32 inner dia
• Suspension on springs at both ends : Phosphor bronze
• Source Threading : 4BA
• Overall dimensions : 87 dia x 210 length
b. PRE-AMPLIFER (TYPE: PA320)
Features
• Solid - state design with FET input
• Choice of two gain factors
• Compact mechanical construction
• High gain stability
Introduction
NUCLEONIX PA320 is a charge sensitive pre-amplifier designed for use with soft x-ray proportional counters. Fully solid-state design and has a choice of two gain factors 1 or 3. Its mechanical construction enables the detector to be directly connected whereas the low output impedance can drive fairly long connecting cable upto the main amplifier.
Specifications
• Detector Load Resistor : 10 Mega ohms
• Output Impedance : 100 ohms
• Charge sensitivity : 0.22x1012 volts / coulomb multiplied by the gain of the unit. The gain can be set by means of a toggle switch to 1 or 3.
• Maximum output pulse : 7.6 volts (saturated output)
• Rise time : Better than 100 nano seconds, for both polarities of the signal.
• Decay time constant : About 50 microseconds at gain 1
• Charge sensitive device : N-Channel FET
• Power requirements : +24V at 30 mA
-24 V at 27 mA
• Temperature range : 10o to 50 o C
• Dimensions : 150W x 112D x 50H mm
• Weight : 0.5 Kg (approximately)
c. MOSSBAUER DRIVE UNIT (TYPE: MD552)
Features
• Mossbauer drive unit MD552 design uses Microcontroller & DAC chip to generate precision Triangular wave form
• Gives SYNC OUT (MCS START) pulse for every 1024 th pulse.
• Receive Time base (cha. Adv) pulses from MCA card to generate precision triangular waveform.
• Drives current into a drive coil (12ohms) in constant acceleration motion.
• Receives pickup coil output as error signal and corrects for non-linearity.
• Designed as a 2-bit module.
• Compatible with Nucleonix make E.M. Velocity Transducer MT170 or its equivalent.
Introduction
Mossbauer Drive unit Type MD552 manufactured by Nucleonix Systems is an integral part of the PC based Mossbauer Spectrometer System. It essentially drives an electromechanical velocity transducer, in constant acceleration mode. This is a two-bit module, designed using state of art electronics (Microcontroller based). It receives external time base pulses from MCA card, running in MCS mode and generates a precision linear triangular waveform through a linear DAC chip, which is amplified and drives the E.M. Velocity Transducer.
Specifications
• Mode of operation : Constant acceleration mode with external time base input from MCA card.
• START : Push button command signal sensed through port of Microcontroller to release 1 st SYNC OUT to MCA card.
• STOP : Push button command signal sensed through port of Microcontroller to stop the drive signal to the transducer at the end of the current sweep.
• SYNC OUT : This is an output signal from this unit to MCA card, which goes as MCS start pulse generated on every 1024 th channel adv. pulse.
• Time Base : This is an incoming signal from MCA card, typically (90 to 100 micro sec) dwell time is selected.
• Drive (BNC) : This provides drive current output to drive coil of EM velocity transducer.
• Pickup (P1 & P2) : At this terminals pickup coil output from EM Velocity transducer is added to drive function output, out of phase to correct for errors.
• Amplitude : 10-turn dial, controls velocity level of transducer. It provides approximately 2.5mm/sec velocity per turn.
• Dimensions : 2 bit modules
• Power : +/-12V from Instrumentation Bin & Power Supply.
d. MINIBIN & POWER SUPPLY (TYPE: MB403)
Introduction
NUCLEONIX MINIM INSTRUMENTATION BIN is a standard Minibin designed to power Standard Nuclear Instrumentation Modules with 24-pin type of power connectors.
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NUCLEONIX MINIM STANDARD INSTRUMENTATION BIN provides mounting space for 8 standard module widths of the 8 ¾ inch high type. The eight corresponding module connectors are provided with necessary wiring for distribution of all standard power supply voltages, +/-12V & +/-24V DC.
A compact Power Supply Unit enclosure is fitted on the rear side of the bin. It has all the circuits built-in to generate +/-12V @1A, +/-24V @0.5A. These D.C. regulated supplies are distributed to the eight Amphenol Connectors of the MINIM bin. The power supply is conservatively rated to power any combination of modules that the bin will physically accommodate. The input voltage can be 220V or 230V AC the DC output power levels that are furnished to the mating bin are +/-12V at 1A each and +/-24V at 0.5A each. Each DC output voltage is adjustable over a +/0.5% minimum range.
All the outputs are regulated and short circuit protected by current limiting.
Specifications of Standard Instrumentation Bin
• INTERCHANGELABILITY : Mechanical tolerance as per standards provided, enable interchangeability of all standard modules
• PANEL DIMENSIONS : Standard rack 8 ¾ inches high and 8 single bits wide excluding, control panel.
• DEPTH BEHIND PANEL : Approximately 10.9 inches
• BIN CONNECTORS : 8 standard connectors 26-190-24 (Amphenol) wired in parallel for standard voltages
• INSTALLED WIRING : All the eight connectors are wired for +12V,-12V,+24V and -24V and high quality GND
• CONSTRUCTION : Bin is constructed with side aluminum with casted handles, top and bottom grilled steel rod mesh with two side channel supports, module guides and a connector plate at the back and a two bit space reserved for power supply module.
• MECHANICAL DIMENSIONS : 11.75" width x 11.00 depth upto connector plate x 8.75" height
Power Supply Unit MB403
• POWER SUPPLY MODULE : This is a compact enclosure seated at the rear side of the bin which generates and provides DC supplies to all the bussed power connectors of the bin
• INPUT Voltage : 230V AC, 50 Hz, +/-10% variation allowed
• DC OUTPUT : +12V DC at 1A ; -12V at 1A, +24V DC at 0.5A; -24V at 0.5A, 48watts maximum output
• REGULATION : Better than +/-0.1%
• STABILITY : +/-0.5% after a 24hr warm up at constant line, load and ambient temperature
• NOISE AND RIPPLE : Less than 3mv peak to peak as observed at the power supply module connector level
• VOLTAGE ADJUSTMENTS : +/- 5% minimum range
• CIRCUIT PROTECTION : Input AC lines fused. Output is protected against short circuit and power supply recovers fully on removing the short circuit
e. HIGH VOLTAGE UNIT (TYPE: HV502)
Introduction
NUCLEONIX offers a standard High Voltage Unit Type: HV502, which is a compact STANDARD/NIM Module (2bit). This is designed to meet the full HV bias requirement for a broad range of Nuclear radiation detectors like GM detectors, ionization chambers, scintillation detectors, photo multiplier tubes, etc,. Apart from this range of applications it also can be used as a high voltage source in areas where high degree of regulation, stability and accuracy are required. Output indication has been provided on a precision ten turn graduated dial and output can be varied by ten turn helipot.
Specifications
• OUTPUT VOLTAGE : 0V to 2000V continuously variable by a ten turn helipot provided on front panel. (All specifications are valid from 10V to 2000V).
• OUTPUT INDICATION : Provided on a precision ten turn graduated dial
• OUTPUT CONNECTOR : MHV Socket (by default), UHF Socket (if specified)
· OUTPUT CURRENT : It can deliver upto a maximum of 1mA.
• OUTPUT POLARITY : The unit is offered with a choice of both POSITIVE or NEGATIVE POLARITY selectable by reversing a polarity PCB. (Provided inside).
• LINE & LOAD REGULATION : Better than 0.005% of full scale.
• RIPPLE : Less than 20mV peak to peak.
• PROTECTIONS : Indefinite protection against overload and short circuit. Under overload the unit doesn’t meet the specifications whereas on removal of short circuit it will recover by itself.
• POWER REQUIREMENT : Draws power from a standard BIN / NIM Power Supply or MINIBIN power supply. +24V at 250mA, +12V at 50mA, -12V at 50mA
• LINEARITY : Better than +/- 0.2%
• TEMPERATURE STABILITY : Better than 100 PPM. (Better temperature stability can be offered at extra cost).
• MECHANICAL DIMENSIONS : Standard 2 bit.
• REAR MODULE CONNECTOR : Amphenol connector Type: 26-159-24P-H (24 pin type) or NIM standard connector as per AEC specifications TID 20893 (Rev) Type : AMP 2041865 optional.
f. ACTIVE FILTER AMPLIFIER (TYPE: AF521)
Introduction
Active Filter Amplifier Type AF521 manufactured by NUCLEONIX is an extremely versatile linear pulse amplifier, intended for use with a variety of radiation detectors. This amplifier has low noise, fast overload recovery, and good linearity and is capable of giving good resolution. It provides semi-gaussian pulse shaping with minimum system noise. This amplifier can be used for amplifying signals from X-ray proportional detectors or scintillation detectors or such other similar detectors.
It accepts either positive or negative detector pulses and can give either unipolar or bipolar output. Typically gains upto a maximum of 1000 are obtainable. Other features include pole zero compensation and control for both coarse, fine gains & shaping times.
Specifications
• Input : Positive or negative, no rise-time limitation, 35 micro seconds minimum decay time constant, for pole zero cancellation. 1K ohms input impedance.
• Output : Positive, Unipolar or bipolar, 0-8 volts linear with 10V saturation
• Shaping : Active integration resulting in approximately gaussian shaping. Shaping time selectable from 1 micro sec to 10 micro sec, in steps of 1 micro sec, choice of either unipolar or bipolar shaping
• Maximum Gain : 1000, COURSE control changes the gain from 1 to 32 binary sequence. FINE gain can be varied 3:1 continuously by a 10 turn helical potentiometer
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• Integral Non-linearity : 0.1%
• Noise : 3 to 4 micro volts or less at maximum gain and 3 micro sec shaping time as referred to input
• Power Requirements : +24V at 25mA ; -24V at 20mA; +12V at 65mA ; -12V at 70mA
• Power Connector : Amphenol Connector Type : 26-159-24P-H (24 pin type) or NIM Standard connector [as per AEC specifications TID 20893 (Rev)]
8k MCA (USB)
Introduction
A Multi-Channel Analyzer (MCA) is an important part of nuclear spectroscopy system. The major requirement of MCA is for nuclear pulse height analysis in energy spectroscopy. The USB-MCA presented here, incorporates state of art technologies like FPGA,USB bus interface and precision analog electronics to meet the stringent system requirements in nuclear pulse spectroscopy. The resolution supported by the USB-MCA ranges from 256 channels to 8K channels selectable via software, making it suitable for all spectroscopy applications from low resolution (e.g. NaI-PMT) to gigh resolution (e.g.HP-Ge) systems.
The USB bus interface of the MCA provides an excellent connectivity with most of the new PCs and lap-top computers. The PHAST application software provided with the USB-MCA, seamlessly integrates with the hardware, featuring a range of standard functions required for analysis and acquisition.
Thus USB-MCA, along with external HP-Ge detector, spectroscopy amplifier and HV supply, forms a complete system for high-resolution spectroscopy applications.
Specifications
Hardware features:
• MCA resolution: 256, 512, 1K, 2K, 4K and 8K channels.
• Spectrum memory : 128K bytes single port SRAM.
• Max counts / channel: 31 bit (2 Giga counts).
• Pulse processing time : 7 ms including ADC conversion time of 5 ms.
• Pile up rejection: Active high TTL input from spectroscopy amplifier
• DNL: + 1%
• INL : + 0.05% F.S.
• MCA Input: Single channel, 0 to +10 volts
• Power requirement: 5V, ~500 mA through USB cable directly (No external power supply required)
MCS mode : This mode facilitates one to acquire data to have time histogram i.e., counts Vs time. Time base can
be set from 10 msec to 100 sec, internally.
Time base signal : TTL signal from 10 msec to 100 sec is made available on MCA card for external use by mossbauer drive unit.
MCS Ext. Start pulse : MCA card receives TTL signal from mossbauer drive unit. One sweep of MCS data acquisition is initiated by this signal, Dwell time per channel will be user selectable by setting time base rate.
Typical mossbauer spectrum window is shown above
Software features:
Important software features include * spectrum display in two windows * marker selection (two) for ROI Detection & bracketing the peaks of interest, multiple ROI selection, delection of ROIs etc.,
File Handling: Involves storing, loading of complete spectrum.
Print: Print of Total graph, selective graph, peak report
Acquistion: With pause option
Erase: Erasing spectrum from memory
Spectrum Analysis: Find peak, Shape calibration, Energy calibration, Approx Calib, Efficiency Calibration, Activity Calculation, etc.,
Spectrum smothing: 3,5,7,9 &11 point smothing functions have been provided
ROI Option: Insert, Delect, Hide Etc.,
Scale: X-axis can be choosen as Channel number (or) Energy axis (in Kev) & Y - axis has range from 256 to 64M in binary steps with auto scaling option. Y-scale can be linear or log
LLD, ULD & base line are soft selectable
In built Isotope library for istope selection & matching.
Analyzer system. It is useful for high resolution X-ray and gamma ray spectrometry work in following areas:
• Isotope research l Universities
• Nuclear reactors l Other R&D
• Accelerators
STANDARD SPECTRUM:
USB 8K MCA Spectrum Plot:
PHA spectrum of massbaurer source
Massbaurer spectrum
Advantages:
The USB-MCA is designed with state of art technologies to meet the stringent requirements of nuclear instrumentation and hence ofers many distinct advantages including the following:
• Excellent MCA performance in terms of resolution, DNL, etc.
• Universal connectivity to a wide range of PCs and notebook computers
• Unlike ISA/PCI cards, it stands outside a PC
• Simple to install, operate and handle
• Low power operration, operates with USB bus power only
• Suitable for portable as well as laboratory class instrumentation
• Easy to manufacture and maintain
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