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Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26, Chandigarh-160019.

Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

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Page 1: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Nuclear Electronics for

Radiation Measurements

Dr. BC Choudhary, Professor

Applied Science Department, NITTTR, Sector-26, Chandigarh-160019.

Page 2: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

RADIATION DETECTORS

Based upon the effect produced when a charged particle or

radiation passes through the matter

IONIZATION or EXCITATION

Solid State Detector

Semiconductor Detectors

Gas Ionization Detectors

Ionization Chambers

Proportional Counters

Geiger-Mueller (GM)Counters

Scintillation Detectors

Page 3: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

General Properties of Radiation Detectors

In any of the detector; Net result of radiation interaction

Appearance of a given amount of charge within detector active medium.

For a single interaction

At time t = 0 to tc,

Total amount of charge generated = Q

Assumption:

Low irradiation rate

each individual interaction

give rise to a current that is

distinguishable.

Page 4: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Modes of Detector Operation

Radiation detectors generally used in Three Modes

Pulse Mode

Current Mode

Mean Square voltage mode

o Pulse mode is easily the most commonly applied, but

current mode also find many applications.

o MSV mode is limited to some specialized applications

that make use of its unique characteristics.

Pulse mode is most frequently used.

Page 5: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Pulse Height Spectrum

The Pulse height spectrum is the distribution

of pulse height and gives the idea of

constitution of flux incident on the detector

or emanated from the source.

Pulse amplitude carries information

regarding charge generated by particular

radiation interaction in the detector

(a) Differential (b) Integral pulse height

spectra for an assumed source of pulses.

(a)

(b)

Represented in two different modes.

• Differential mode

• Integral mode

Number of pulses

between H1 & H2

2

1

H

H

dHdH

dN

Total number of pulses

under distribution N0

0

dHdH

dN

Page 6: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Properties of Detector

Energy Resolution : An important property of a detector

Ability of a given detector or

measurement to resolve fine details of

two events

Good Energy Resolution

Poor energy resolution

Response functions for detectors with

good and poor resolution

FWHM : Width of the distribution at a

level that is just half the maximum height

(ordinate) of the peak

0H

FWHMR Resolution

Page 7: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

FWHM

Energy

Energy

Co

un

ts

Potential sources for imperfect

energy resolution of a detector :

Operating Characteristics of detector &

their drift.

Random Noise in detector and associated

electronics.

Statistical fluctuations in number of charge

carriers produced due to interaction of

quantum of radiation of same energy.

2 .

2

.

2

.int

2

noisestnoiserantotal FWHMFWHMFWHMFWHM

Resolution is a dimensionless fraction expressed as a percentage.

100% Energy

FWHMR

Smaller the figure for ‘R’; better the

detector able to distinguish between

two radiations whose energies lie near

each other.

Page 8: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Detection Efficiency

Measure of response of a detector to the incident radiations

In case of photon counters, all the quanta do not deposit their

complete energy and hence are not recorded. The concept of

efficiency becomes important for such detectors.

Efficiency of a detector depends upon:

(i) Detector medium

(ii) Dimensions of detector.

(iii) Source to detector distance.

(iv) Nature of radiation being measured.

Efficiency defined in two different ways

• Absolute Efficiency

• Intrinsic Efficiency

Page 9: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Absolute Efficiency

sourcethebyemittedquantaof.No

recordedpulsesof.Noabs

Depends on detector properties and also on details of counting geometry

Intrinsic Efficiency

ectordetonincidentquantaof.No

recordedpulsesof.Noint

No longer include the solid angle subtended by the detector

For Isotropic Sources; Absolute and intrinsic efficiencies are

related through

absint

4

- solid angle of detector seen from

actual position.

Much more convenient to tabulate values of intrinsic efficiency

because of milder geometric dependence.

Page 10: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Counting Efficiencies

Counting efficiencies also categorized by the nature of the

event recorded

Total Efficiency : If we accept all pulses from the detector . In this case

all interactions, no matter how low in energy, are assumed to be counted.

Entire area under the spectrum is considered.

Photo peak Efficiency: Only those interactions that deposit the full

energy of the incident radiation are counted.

Peak -to-Total ratio : Total

Peakr

A measure of figure of merit

of detectors

Often preferable for an experimental standpoint to use only peak

efficiency because it is not sensitive to perturbation effects.

Page 11: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Energy Resolution

Comparison of pulse height spectra recorded by

three different detectors.

Semiconductor detectors Si(Li)

have best energy resolution

among all types of the radiation

detectors

Page 12: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Efficiency Comparison

Peak efficiency for five different detectors as a function of incident

X- or gamma ray energy.

Page 13: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Measurements using Radiation Detectors

Energy Measurements

• Measures the energy of the incident radiations.

• It is used in counting systems. Mostly single mode

• Records the spectrum from various types of interaction

taken place in the detector in term of voltage pulse.

Time Measurements

• Measure the time elapse between two incident events

• Used in coincidence mode

Radiation application normally involve Energy measurements.

The output signal amplitude is further processed to extract the

desired information.

Page 14: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Energy Measurement

What is the shape of the spectrum for a large detector?

Page 15: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Nuclear Electronic Instruments

Block Type : Each unit is self contained and

independent block.

NIM Standard: Modular form- Units are not self

contained. They can be fitted in a BIN and Power

supply as per requirement.

Generally Categorized in Two Types

Page 16: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Self Contained Block Modules

Page 17: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

NIM Electronics

NIM units along with Bin for

power supply

Page 18: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Counting Instrumentation

A Simple Counting System

Page 19: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Proportional Detector Counting System

GM Counting System

Page 20: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Scintillation Counting System

Page 21: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Single Channel Counting System

Dual-channel photon-counting system

Page 22: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Simple Coincidence Counting System

Page 23: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Time Measurements

Typical Fast /slow Timing System for Coincidence

measurements with scintillatores

Page 24: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Pulse Processing and Shaping

Purpose is to extract information from the pulses produced

by the radiation detectors.

Major steps involved to process and shape the pulse to get

required information are :

Device Impedance

Coaxial Cables

Pulse Shaping

Linear and logic pulses

Pulse counting System

Pulse Height Analysis System

Page 25: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Device Impedance

For ideal device response

High Input Impedance

Low Output Impedance

Important to consider is the impedance of the device that

comprise the signal processing chain.

Idealized input and output configuration

LO

LSL

ZZ

ZVV

Page 26: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Coaxial Cables All interconnections of components in a signal chain for nuclear detector

pulses is carried out using shielded coaxial cable

• Shielded construction is designed to

minimize pickup of noise from stray

electric and electromagnetic fields.

• To preserve the flexibility of the cable,

the outer shield is usually made of

braided strands of the copper wire.

In signal cables, the important specifications are the characteristic impedance

and the capacitance per unit length.

In cables intended to carry bias voltage to detectors, the maximum voltage

rating is important.

Velocity of propagation is proportional to

For Polyethylene v 66% of c k

1k - dielectric constant of

conductor

Page 27: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

No cable is a perfect transmission line. There will always be dissipative losses due

to imperfect dielectric and resistance of the center conductor that will result in

some attenuation & distortion of the transmitted pulse.

Page 28: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Various Type of Coaxial cables

Page 29: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Various Coaxial

Cables &

Accessories

Page 30: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Adapters & Terminators

Various types

of terminators

Various types

of adapters

Page 31: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Pulse Shaping

Often desirable to change the shape of the signal pulse in

some predetermined fashion.

• Most common application is in

processing a train of pulses

produced by a preamplifier.

• If the rate of interaction in the

detector is not small, these pulses

will overlap one another giving

rise to apparent variation in

amplitude

Amplitude carries the basic information of charge deposited in detector, the

pileup of pulses, can be a serious problem.

Ideal solution is to shape the pulses in such a way as to produce a pulse train.

Here all the long tails have been eliminated, but the amplitude carried by the

maximum amplitude of the pulse has been preserved.

Page 32: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Linear and Logic Pulses

Virtually all radiation detector signal chains start out with

linear pulses and, at some point, a conversion is made to logic

pulses based on some predetermined criteria.

In any pulse processing system, important to distinguish

between two types of signal pulse.

• Linear pulse: A signal pulse that carriers information through the

amplitude, and sometimes by its shape as well. A sequence of linear pulses

may therefore differ widely in size and shape characteristics.

• Logic pulse: A signal of pulse of standard size and shape which carries

information only by its presence or absence or by the precise time of its

appearance.

Page 33: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

NIM Standard

Nuclear Instrument module (NIM) standard recommends

• Shaped linear pulses be one of the specific dynamic range

0 to + 1V (for ICs)

0 to + 10V (for transistor-based circuits)

• Standard logic pulses are used in normal applications when the

potential counting rate does not exceed 20 MHz.

Output (must deliver) Input (must respond to)

Logic 1 +4 to +12V +3 to +12 V

Logic 0 +1 to -2V +1.5 to -2V.

Page 34: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Components Common to many Applications

Preamplifiers

Fundamental output of all pulse type radiation detectors is a burst of charge

Q that is liberated by the incident radiation.

In most of detectors except G-M tube and scintillation counter, the charge is

so small that it is impractical to deal with the signal pulses without an

intermediate amplification step.

• The first element in a signal processing chain is

therefore often a preamplifier

• Provides an interface between the detector and the

pulse-processing and analysis electronics that

follows

Preamplifier is usually located as close

as possible to the detector.

Page 35: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Preamplifiers in Semiconductor Detectors

Expanded views of detector capsules with

horizontal & vertical dipstick cryostat. In

these detectors, preamplier is also kept at low

temperature.

Page 36: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Semiconductor Detectors

Detector dipped in LN2 cryostat

Detector

Capsules

&

Assemblies

Page 37: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

• One function of preamplifier is to terminate the capacitance

quickly and therefore to maximize S/N ratio.

• Also serves as an Impedance matching device.

From S/N point, always preferable to minimize the capacitive

loading on the detector, and therefore long interconnecting

cables between detector and preamplifier should be avoided.

Preamplifier conventionally provides no pulse shaping, and

its output is a linear tail pulse.

Rise time of the output is kept as

short as possible,

Decay time of the pulses is made

quite large for full collection of

charge from detector. Preamplifier pulses

Page 38: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Preamplifier can be either the Voltage Sensitive or

Charge Sensitive type.

(Assume A >>> R2/R1) in

1

2out V

R

RV

Voltage Sensitive : More conventional in many electronic applications

where C is the input capacitance C

QVi

• Consist of a simple configuration that

provides an output pulse whose amplitude

is proportional to the amplitude of the

voltage supplied to its input terminals.

Detector capacitance may change with operating parameters. In

this situation, a voltage sensitive preamplifier is undesirable

because the proportionality between Vmax and Q is lost.

Page 39: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Charge Sensitive Configuration : In this circuit, the output voltage

is proportional to the total integrated charge in the pulse provided to

the input terminals, as long as the duration of the input pulse is short

compared to the time constant RfCf.

Assume A >> (Ci + Cf)/ Cf

fi

inoutC)1A(C

QAAVV

f

outC

QVor

Thus changes in the input capacitance no longer have an

appreciable effect on the output voltage.

Page 40: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Detector Bias & Bin Power Supply

Bin and power supplies for NIM modules

Low and High detector bias supplies

Page 41: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Amplifier

Front & Rear views

Output from the preamplifiers are provided to a linear

amplifier element in the pulse processing chain.

Conventionally provides two primary functions:

Pulse shaping and Amplitude gain.

Accept tail pulses as an input of either polarity, and

produces a shaped linear pulse with standard polarity

and span.

Standard amplifiers are provided with

• Variable, amplification factor or gain,

• Shaping time,

• Pole-zero cancellation and base line restoration.

• Provides output pulses: Unipolar & bipolar

Page 42: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Pulse with pole-Zero adjustment

Pulse without and with pole-Zero adjustment

Output Pulses & Pole-Zero

Type of output pulses

from amplifier

Unipolar Output

Page 43: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Effects of Pole-Zero Cancellation

Page 44: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Pulse Counting System

Integral Discriminator

Differential Discriminator

(Window mode)

Page 45: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Single Channel Analyser

SCAs monitor the height of

the shaped linear pulses and

convert to logic pulses

according to discriminator

mode selected.

• In a counting system, the logic

pulses must be accumulated

and their number recorded

over a fixed period of time

• Devices used for this purpose

include counters, timers or

counting rate meters

Linear to logic pulse conversion

Page 46: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Timer, Counters & Counter-Timer

Page 47: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Multi Channel Analyzer (MCA)

Next to simple counting of pulses,common procedure in

nuclear measurements involves recording the amplitude

distribution of pulses produced by a detector.

An analogy representing pulse-height sorting function

in the multichannel pulse height analyzer

Objective is to deduce

properties of the incident

radiations from the position

of peaks in the recorded

spectrum.

Device designed to carry this

function is known as

multichannel pulse height

analyzer (MCA)

Page 48: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

MCA consist of three main sections:

• Analog to digital converter (ADC),

• Memory and

• Display

ADC measures the amplifier pulse peak amplitude and convert it to a digital

number. This number represents the address of a memory location in the

analyzer memory. The number of times a pulse of each height has been detected

is accumulated in the analyzer memory to form the spectrum of pulse heights.

Subsequently, this information can be displayed as a picture of the analyzer

energy spectrum.

MCA can performs a number of functions like data acquisition and storage,

dead time correction, display manipulation, linear and quadratic energy

calibration, spectrum stripping and smoothening etc.

Stored data can be transferred to either on storage media or listed out on

printers.

Page 49: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Analog to Digital Converter (ADC)

Page 50: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Typical Spectrum

Page 51: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Comparison of

spectrum recorded

using a NaI(Tl)

and Germanium

detectors.

Page 52: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Typical X-ray Spectra recorded with a Si(Li) low energy photon

detector.

Page 53: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Conversion electron spectrum from 140Ba decay taken with

Si(Li) detector in an electron spectrometer.

Page 54: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Bismuth Germanate (Bi4Ge3O12)

(BGO)

A HPGe detector surrounded by a

Compton suppression system made up

of NaI(Tl) and BGO scintillators Pulse height spectra of Co60 gamma-

ray source using Anti-Compton shield

Page 55: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Intrinsic Photopeak efficiencies for BGO

and NaI(Tl) scintillators of equal size. Measurements of light pulse shapes

from BGO and NaI(Tl)

Comparison of Response of BGO and

NaI(Tl) Scintillators

Page 56: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Detector arrangements for In-Beam Studies

• Placement of detectors a

appropriate angles is very

important to minimize

angular distribution effects.

Page 57: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Multi-Detector Systems

INGA at BARC-TIFR, Mumbai

GDA at IUAC Delhi

Page 58: Nuclear Electronics for Radiation Measurements · 2019. 1. 1. · Nuclear Electronics for Radiation Measurements Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26,

Email: <[email protected]>

Cell: 09417521382