Neutron & Gamma ray Spectrometrynewuc.jinr.ru/img_sections/file/Practice2016/Egypt... · Ahmed...

Hassan

Amany

Noura

Ahmed

Ali

HANAA* Humans Applying Neutron Activation Analysis

Material Analysis Using Characteristic Gamma Rays from Neutron Induced Nuclear Reactions

Ahmed Abd Elfatah Elhoushy, Nuclear Engineer, Alexandria University, Faculty of Engineering,

Nuclear & Radiation Engineering Department, Prompt Gamma Neutron Activation Analysis in

Mining

Yasser Farrag Ali, Biophysics Laboratory, Physics Dept., Faculty of science, Al-Azhar University,

Shielding of BGO probe from 239Pu-Be neutron-gamma radiation

Noura Hassan, Assistant Lecturer in physics, Faculty of Engineering, Egyptian Russian University,

Feasibility study of humidity of furnace coke by neutrons

Ahmed Mohamed Hassan, Assistant Lecturer, Physics Department, Faculty of Science, Mansoura

University, Measurements of gamma-ray activity of environmental samples from Egypt

Neutron & Gamma

ray Spectrometry

Amany Hamdy Abdullah, Radioactive Isotopes Production Facility, Egyptian Atomic Energy

Authority ETRR-2, Optimizing the shielding of TANGRA NaI(Tl) array

* HANAA means:

Happiness, Bliss, Felicity,

Joy, Peace,….

Measurements of gamma-ray activity of environmental

samples from Egypt

By

Mr/ Ahmed Hassan

Assistant lecturer, Mansoura university, Egypt

Supervision: Dr. Ivan Ruskov, Senior scientist, FLNP

Mr. Constantin Hramko, engineer, FLNP

Aim of the work.

Experimental work.

Sample Preparation and HpGe setup.

Results and discussion.

Conclusions.

References.

Outline

Study of activity concentration of natural radionuclides such

as 226Ra , 232Th and 40K around this area in plant samples to evaluate the potential health hazards on general public.

The Problem

Contamination process due to production operation of certain

components that contain hazard materials around fertilizer

factories area.

Experimental work (samples locations and

preparation)

Plant sample

Washing

Drying

Powder Polyethylene

Container 4W Counting

Results and discussion

This figure shows the variation of

activity concentrations of 226Ra and 232Th at different positions.

This figure shows the variation of

activity concentrations of 40K at

different positions.

The obtained results illustrate the following

observation, the study area is still in the zones of

normal radiation level except position P1L which

are higher than the permissible maximum values

for indoor and outdoor exposures .

It was recommend to avoid this area for public

health.

Conclusions

References

Assessment the shielding property of iron for BGO scintillation detector from 239Pu-Be

neutron source

Shielding of scintillation detectors from direct penetration of neutrons from the source. Especially, when there is willing to study the interaction of fast neutron with medium and heavy nuclei “detect secondary nuclear radiation (neutrons and gamma quanta)”

Elastic scattering Inelastic scattering

Neutron capture

Compound nucleus

239PuBe

Neu

tro

n S

ourc

e

Spontaneous fission of heavy nuclides

Isotopic neutron source

Based on (γ,n) and (α,n) reaction in beryllium

BGO (Ø76 x 65 mm)

Data acquisition system (DAQ): MCA ADCM

and its software main panel LINUX operation system

ADCM – digitizing of the

analog signals and store the

time-amplitude of each of them

in list-mode (one-by-one)

(.DAT)

C++ ROMANA and

TOFANA – analyze the list-

mode .DAT files and create

.ROOT files containing the

histograms (Energy- and Time-

distributions) of the recorded

events.

ROOT scripts – for calculation

of channel-energy calibration

curves and determine the

efficiency of gamma-ray

detectors.

ADCM16-LTC, 16-channel/ 14-bit/100MHz,

ADC-boards from AFI™ Electronics.

Iron of thickness at least 30 cm compared to lead allows

one to achieve the highest suppression factors at for the

count rate.

Based on these results, It is recommended to use iron

instead of lead, because it has many advantages:

• Cheap.

• Has less mass than lead.

By

Amany Hamdy Abdullah

Optimizing the shielding of

TANGRA NaI(Tl) array

Supervisor

Dr. Ivan Ruskov, senior scientist @ FLNP

TANGRA (TAgged Neutrons & Gamma RAys)

TANGRA-project has been recently started in

Frank Laboratory of Neutron Physics (FLNP) of

the Joint Institute for Nuclear Research (JINR)

in Dubna to study some important for

fundamental and applied nuclear physics

reactions (n,n), (n,n'γ), (n,2n), (n,f), (n,gf),

induced by 14.1 MeV neutrons.

Main components:

In the frame of TANGRA-project some experimental

work was done in order to choose the optimum type and

thickness of a shielding to protect NaI(Tl) scintillation

gamma-ray detectors from the ING-27 direct 14.1 MeV

neutrons.

Data acquisition system (DAQ)

LINUX operation system

ADCM – digitizing of the

analog signals and store the

time-amplitude of each of

them in list-mode (one-by-

one) (.DAT)

C++ ROMANA and

TOFANA – analyze the list-

mode .DAT files and create

.ROOT files containing the

histograms (Energy- and

Time-distributions) of the

recorded events.

ROOT scripts – for

calculation of channel-energy

calibration curves and

determine the efficiency of

gamma-ray detectors.

MCA ADCM and its software main panel

The objective of this study was to investigate the

shielding effectiveness of different combination

of layers from lead (Pb), iron (Fe), polyethylene

(PE) and/or borated polyethylene (BPE)

Experimental setup

The shields, composed from layers of different materials,

was positioned between the neutron generator ING-27

and the investigated hexagonal NaI(Tl) scintillation

probe as shown below.

Number of events No and Nd was determined from

the corresponding gamma-ray pulse-height spectra

(number of events per amplitude channel) as a

function of the light output (LO) of the NaI(Tl)

scintillator in MeVee units (equivalent to 1 MeV

electron light output).

Experimental results

Fig. 4. Amplitude distributions of events recorded by NaI(Tl) probe

located behind 10, 20, 30, 40 and 50 cm thick Fe shields, compare with

that of the bare probe, in the NaI(Tl) scintillator light output interval of

LO = 2.0 6.9 MeVee.

2.4 3.2 4.0 4.8 5.6 6.40

2

4

6

8

10 Fe, d

0 cm

10 cm

20 cm

30 cm

40 cm

50 cm

Num

ber o

f eve

nts (

x103 )

Amplitude (MeVee)

Fig. 5. Amplitude distributions of events recorded by NaI(Tl)

probe behind 50 cm thick Fe and Pb shields in the interval of

LO = 2.8 6.9 MeVee. The lowest light output limit was LO =

0.2 MeVee.

2.8 3.6 4.4 5.2 6.0 6.83.2 4.0 4.8 5.6 6.4

200

400

600

800

1000

1200

1400N

umbe

r of

eve

nts

Amplitude (MeVee)

50 cm Fe

50 cm Pb

Fig. 6. Amplitude spectra of events recorded by NaI(Tl) probe behind

50 cm thick.

2.8 3.2 3.6 4.0 4.4 4.8 5.2 5.6 6.0 6.4 6.8

200

400

600

800

1000

1200

1400

Nu

mb

er o

f ev

ents

Amplitude (MeVee)

Fe(40cm)+BPE(10cm)

Fe(30cm)+BPE(10cm)+Pb(10cm)

Fe(20cm)+BPE(10cm)+Pb(20cm)

Fe(10cm)+BPE(10cm)+Pb(30cm)

From Fig.6 one can conclude that

a) In the presents of BPE it is important to have

additional heavy metal shield before NaI(Tl) to

suppress gamma-rays from the interaction of the

moderated (by Fe) neutrons with the BPE-nuclei

and

b) In the case of triple-layer shields, the

complementary thicknesses of Fe and Pb shown

the same level of suppression in the range of

experimental data uncertainties.

Discussion and conclusions A shield with both Fe and BPE could be more effective than just

Fe or BPE alone, because the advantages of both Fe and BPE are

utilized. Iron (Fe) is effective in slowing down high-energy

neutrons (e.g., 14-MeV source neutrons) and attenuating gammas,

while hydrogen of BPE is effective in slowing down fast neutrons

(till a few MeV), and 10B has a high absorption cross section for

thermal neutrons and a low production yield of gammas. So, a

shield made of 30cm Fe followed by a 20 cm BPE-layer can

meet the goal.

According to the experimental results obtained in this

methodological work, three layer shields made of

Fe(30cm)+BPE(10cm)+Pb(10cm) or

Fe(20cm)+BPE(10cm)+Pb(20cm) provided the highest

suppression factors on the hexagonal NaI(Tl) gamma-ray detector

load.

Thank you for your attention

2012

By

Noura Hassan Ibrahim

Physics Demonstrator , ERU

Under Supervision

Prof. Dr. Samir Yousha El-Khamessy

Professor of Nuclear Physics, Physics Dep. , ASU

Dr. Hesham Ibrahim Shahbunder

Assistant Professor of Nuclear Engineering, Physics Dep., ASU

Dr. Ashraf Hamed

Assistant Professor

By

Assistant Lecturer, Faculty of Engineering, Egyptian Russian University

Under supervision

Senior scientist @ Frank Laboratory of Neutron Physics, JINR

OUTLINE

Introduction

Neutron and Gamma-ray Spectrometry.

Literature review.

Aim of the work.

Methodology.

Experimental set-up.

Results & Conclusion.

39

Introduction 40

Gamma-ray spectrometry is an analytical method that allows the identification and quantification of gamma emitting isotopes in a variety of matrices.

Neutron and Gamma-ray Spectrometry 41

Literature Review

A. El Abd; A method for moisture measurement in porous media based on epithermal neutron scattering; Applied Radiation and Isotopes; 2015.

P. Peter; In-Situ element analysis from gamma-ray and neutron spectra using a pulsed neutron source; University of Groningen; 2010.

A. Anaqvi; Moisture measurements of wood and sugar samples using neutron transmission technique; Nuclear instruments and methods in physics research; 2003.

R. Ziemer; Effects of neutron source type on soil moisture measurement; USDA-Cal.

I. Goldeberg, et. al.; measurement of moisture content and density of soil masses using radioactive methods; LUNAR

42

Literature Review 43

Study the possibility of determining the humidity of

furnace coke using 239Pu-Be source

Aim of the Present Work 44

• The proposed method for determining the humidity

of a test sample by the analysis of spectra of prompt

gamma rays that emitted from the test sample after

irradiated by fast neutron.

• The humidity of test sample can be determined from

the characteristic gamma lines of Hydrogen and

Oxygen.

Methodology 45

Interaction of neutron with water 46

Fig. 1: Interaction of Neutron with Nucleus

Neutron capture Fast neutron Inelastic scattering

1H(2223.25 KeV)

16O(6129 KeV)

Experimental Setup

239Pu-Be source (A=5*106n/s)

BGO scintillation detector

Combined shielding bricks

(Fe + Bi).

A computerized 16-channel read out system.

47

Experimental Setup

LINUX operation system ADCM – digitizing of the analog signals and store the time-amplitude of each of them in list-mode (one-by-one) (.DAT) C++ ROMANA and TOFANA – analyze the list-mode .DAT files and create .ROOT files containing the histograms (Energy- and Time-distributions) of the recorded events. ROOT scripts – for calculation of channel-energy calibration curves and determine the efficiency of gamma-ray detectors.

48

Data acquisition system (DAQ): MCA

ADCM and its software main panel

A 2 kg coke sample, containing a variable

amount of water (from 2% up to 80%), was

irradiated with 239Pu-Be neutrons every time for

10 hours

Results and Discussion 49

Results 50

Results 51

Results 52

These measurements show that it is possible to

determine the amount of water, added into the

coke sample, analyzing the characteristic

gamma-ray spectra.

Conclusion 53

54

Prompt-gamma neutron activation analysis in mining

By

Ahmed Abd El fatah Elhoushy Nuclear Engineer ,Faculity Of Engineering, Alexandria University

Supervisor

Dr / Ivan Ruskov Senior Scientist , Frank Laboratory Of Neutron Physics

Outline

• Introduction

• Experimental work

• Results and discussion

• Conclusions

Introduction • What is Neutron Activation

Analysis (NAA)?

NAA is a method for qualitative and quantitative determination of elements based on the measurement of characteristic radiation from radionuclides formed by neutron irradiation of the material.

• According to type of emitted γ-ray measured

If the Prompt γ-ray is the measured radiation

Prompt γ -ray neutron activation analysis (PGNAA)

The measurements take place during irradiation.

If Delayed γ-ray is the measured radiation.

Delayed γ -ray neutron activation analysis (DGNAA)

The measurements take place after a certain decay period.

An experiment for deterimining the elemental composition of material by (PGNAA) using 239Pu-Be neutron source.

used reaction is

Inelastic scattering (n, n’ γ)

Aim of the work

Experimental work

An experiment setup for deterimining the elemental composition of material by (PGNAA)

We use a 239Pu-Be as source of continous neutron flux with energy around 4.2 Mev

To register gamma rays coming from interaction of neutrons with nuclei we use HPGe detector .

To protect the detectors from direct radiation of neutron source we use shielding of Pb/Bi of nearly 30 cm total length

Experimental work Three types of ore samples for analysis

Table 1. Content of different controlled elements in phosphate ore

1. Concentrate sample with high concentration of P2O5-38,95%

2. Tail sample with low concentration of P2O5 – 0,9%

3. X sample (mixture) with concentration of P2O5 between the value of first and second

Tails, mass

%

concentrate,

mass %

Controlled

element

0.90 38.98 P2O5

20.88 0.99 Al2O3

4.90 50.58 CaO

42.16 2.38 SiO2

8.02 0.68 Fe2O3

6.02 0.24 K2O

0.15 0.06 H2O

2.92 0.33 TiO2

10.26 0.50 Na2O

Experimental work

Back ground radiation curve was recorded without sample inside. Important step in work

with any gamma-spectroscopy instrument is to have well done channel-energy calibration.

In our case the calibration was performed by two methods:

1. by standard point sources (60Co & 137Cs)

2. by irradiation of metal samples.

60Co : 1173.2 and 1332.5 KeV

137Cs : 661.7 KeV

The channel-energy calibration curve

Results and discussion

• in the figure below is shown the comparison between gamma-spectra from three irradiated samples (concentrate – black , tails – red, X“mixture” – purple) and background –blue )

Part of gamma-ray energy

spectrum (2.0 - 2.5) MeV

Figure 1. Part of gamma-ray energy spectrum (2.0-2.5 MeV). Figure 2 Comparison of the energy resolutions of HPGe and

BGO detectors.

• In Figure 2 is shown the comparison between the measurements made with different types of detectors:

HPGe (with high resolution)

BGO (with high efficiency)

• Although BGO has a higher efficiency of gamma-ray detection, it has a moderate energy resolution.

• For example: if we compare Figure 1 with Figure 2 especially the interval between 2.20 and 2.25 MeV, .

in case of HPGe we can see that there are three lines from different sources (27Al, background and 31P).

In case of BGO (Figure 2, green and dark-blue lines) these gamma-lines, either from concentrate or from tails samples, can not be divided.

γ-line

energy,

keV

Attachment

(Concentrate

/Tails)

Isotope Table

energy, keV

751 Concentrate SE 31P 1266,13

766 Concentrate 44Ca 761,12

843 Mixture 27Al 56Fe

843,76

846,76

983 Tails 48Ti 983,54

1014 Tails 27Al 1014,52

1156 Concentrate 44Ca 1157,02

1238 Mixture,

Tails

56Fe 1238,27

1266 Concentrate 31P 1266,13

1369 Mixture 56Fe 39K

1360,21

1360,60

1635 Tails 23Na 1635,96

1811 Mixture,

Tails

56Fe 1810,76

2151 Concentrate 31P 2148,40

2213 Tails 27Al 2212,01

γ-line

energy,

keV

Attachment

(Concentrate

/Tails)

Isotope Table

energy,

keV

2237 Concentrate 31P

2233,60

2239,80

2275 Mixture,

Tails

56Fe

23Na

2273,20

2276,13

2263,39

2523 Mixture 56Fe 39K

2523,06

2522,40

2814-

2846

Tails 28Si 27Al 48Ti 39K

2838,29

2836,40

2819,08

2814,24

3132 Concentrate 31P 3134,30

3223 Concentrate SE 40Ca 3736,30

3732 Concentrate 40Ca 48Ti

3736,30

3738,35

7580 Mixture,

Tails

48Ti 7585,00

Some of the Identified Isotopes gamma-lines in the acquired spectra.

Conclusions

• An experimental setup for determining the elemental composition of materials by prompt gamma-ray neutron activation analysis (PGNAA) was commissioned and tested.

• The acquired spectra was processed and decoded successful.

Thank you for your attention