EXPERIMENTAL PROCEDURES - Chiang Mai University

CHAPTER 3

EXPERIMENTAL PROCEDURES

3.1 Materials and measurement equipments

3.1.1 Glass mixture preparations

3.1.1.1 Chemicals

(1) Sodium carbonate (Na2CO3), commercial grade

(2) Potassium carbonate (K2CO3), commercial grade

(3) Calcium oxide (CaO), commercial grade

(4) Magnesium oxide (MgO), commercial grade

(5) Aluminum oxide (Al2O3), commercial grade

(6) Boric oxide (B2O3), commercial grade

(7) Barium carbonate (BaCO3), commercial grade

(8) Barium sulfate (BaSO4), commercial grade

(9) Titanium oxide (TiO2), AR grade

(10) Zirconium oxide (ZrO2), AR grade

(11) Bismuth oxide (Bi2O3), commercial grade

(12) Lead oxide (Pb3O4), commercial grade

(13) Silver nitrate (AgNO3), AR grade

(14) Copper (II)oxide (CuO), AR grade

(15) Chromium (III) oxide (Cr2O3), AR grade

(16) Iron (III) oxide (Fe2O3), AR grade

(17) Cobalt (II) oxide (CoO), AR grade

59

(18) Gold metal (Au), ≥99 %

(19) Selenium powder (Se), AR grade

(20) Cadmium sulfide (CdS), AR grade

3.1.1.2 Natural Raw Materials

(1) Quartz sands (SiO2)

(1.1) local sites from Chanthaburi, Trat, Rayong, Chumphon,

Nakhon Si Thammarat, Pattani, Phuket, Songkhla, Nong Khai and Tak Provinces

(1.2) foreign sites from Republic of Austria, Kingdom of Belgium,

Federal Republic of Germany, Japan and U.S.A.

(2) Dolomite (CaMgCO3) from Kanchanaburi Province

(3) Feldspar (KAlSi3O8) from Ratchaburi Province

(4) Limestone (CaCO3) from Phrae Province

(5) Barite (BaSO4) from Loei Province

3.1.1.3 Analytical balance; A&D, EK 200G, with accuracy ±0.01 g

3.1.1.4 Accessories

(1) Spectacles

(2) Gloves, rubber

(3) Crucible

(4) Spatula

3.1.2 Glass melting process

3.1.2.1 Furnaces

(1) Electric furnace; 1250 °C, ≤ 500g sample weight

- The Glass and Glass Products Research and Development

Laboratory, the Science and Technology Research Institute, Chiang Mai University

60

(2) Electric furnace: 1500 °C, ≤ 500 g sample weight

- The Department of Science Service, Ministry of Science and

Technology, Bangkok

(3) Gas furnace; 1400 °C, ≤15 kg sample weight, LPG

- Lotus Crystal International Co.Ltd., Rayong Province

(4) Gas furnace; 1400 °C, ≤250 kg sample weight, Furnace oil

- Sampran Co.Ltd., Nakhon Pathom Province

3.1.2.2 Accessories

(1) Gloves, anti-heat

(3) Pincers

3.1.3 Instruments

3.1.3.1 Digital camera; Sony Cyber Shot

3.1.3.2 Stereo microscope; Nikon Optophot 2- POL (Department of Earth

Sciences, Faculty of Science, Kasetsart University, Bangkok)

3.1.3.3 Scanning electron microscope (SEM); Jeol JSM-5910, operated at 20 kV

(Faculty of Science, Chiang Mai University, Chiang Mai)

3.1.3.4 Wavelength dispersive X-rays fluorescence spectrometer (WDXRF);

Phillips MagixPro PW 2400, operated with LiF 200 crystal, scintillation and flow

proportional detectors, Rh-tube at 60 kV, 125 mA (Department of Geological Sciences,

Faculty of Science, Chiang Mai University, Chiang Mai)

3.1.3.5 X-ray diffractometer (XRD); Jeol JDX-7E, operated in the 2θ angle

between 10-58.4° with a scanning speed of 4°/min at 40 kV and 15 mA (Department of

Physics, Faculty of Science, Chiang Mai University, Chiang Mai)

61

3.1.3.6 Particle size analyzer; Malvern Instrument MasterSizer, using

polydisperse analysis, and operated with beam length at 240 mm and range lens at 300 RF

mm (The Ceramic Industrial Development Center, Lumpang)

3.1.3.7 Analytical balance; Mettler Toledo AG 104, using distilled water as

immersion liquid, with accuracy ± 0.0001 g/cm3 (Department of Earth Sciences, Faculty

of Science, Kasetsart University, Bangkok)

3.1.3.8 Dilatometer; Anter Unitherm 1161, (The Science Service Department,

Ministry of Science and Technology, Bangkok)

3.1.3.9 Microhardness tester; Shimadzu DMH-2 (The Fast Neutron Research

Facility, Faculty of Science, Chiang Mai University)

3.1.3.10 Refractometer; Rayner Duplex II, with refractometer fluid nD ≤ 1.79,

operated at room temperature by using the sodium light at 589 nm, with accuracy ± 0.005

(The Glass and Glass Products Research and Development Laboratory, Institute for

Science and Technology Research and Development, Chiang Mai University)

3.1.3.11 UV-Vis-NIR spectrophotometer; Perkin Elmer Lambda 900, operated

in a spectrum range 300 – 800 and 200-1300 nm, with accuracy ± 0.8 nm in UV-Vis

range and ± in 0.2 nm in IR range (Department of Earth Sciences, Faculty of Science,

Kasetsart University, Bangkok)

3.1.3.12 Proton Induced X-ray Emission (PIXE) analysis, based on the 1.7 MV

Tandetron accelerator (The Fast Neutron Research Facility, Faculty of Science, Chiang

Mai University)

3.1.3.13 LCR meter; Hewlett Packard; HP 4284A, magnitude and frequency test

at 1.0 V and 1 MHz, standard dielectric constant of air; 1.00 (Department of Physics,

Faculty of Science, Kasetsart University, Bangkok)

62

3.1.3.14 Color portable set; GIA Gem Instruments 324 GIA GemSet, in terms of

the hue, tone, and saturation, under D65 K light source (Department of Earth Sciences,

Faculty of Science, Kasetsart University, Bangkok)

3.1.3.15 NaI(Tl) detector; Teledyne Brown Engineering, with the scaler;

Ludlum Measurements Inc. Model 2000, using gamma radiation source Ba-133 and Cs-

137 from Isotope Products Laboratories (Faculty of Associated Medical Sciences, Chiang

Mai University )

3.2 Morphology and composition of quartz sand

•

••

Tak

Chumphon

Phuket

Pattani Songkhla

Nakorn Sri Thammarat

Trat

Chantaburi

Rayong

NongKhai

Figure 3.1 Local quartz sand sites

Nakhon Si Thammarat

Chanthaburi

63

The geological explorations of the quartz sand samples were carried out in ten

various localities in Thailand such as Chanthaburi, Trat, Rayong, Chumphon, Nakhon Si

Thammarat, Pattani, Phuket, Songkhla, Nong Khai and Tak provinces, as shown in Figure

3.1, and five various sites from Austria, Belgium, Germany, Japan and U.S.A.

The physical structure investigations of the quartz sand samples both from local

and foreign sites were determined using a digital camera, an optical stereo microscope

and a scanning electron microscope.

The chemical composition of these samples was determined by a wavelength

dispersive X-ray fluorescence spectrometer.

The grain distribution of these samples from was analyzed by using the particle

size analyzer.

3.3 Glass sample preparation

3.3.1 Colorless glass sample preparation in the laboratory scale

3.3.1.1 Preparation of the glass samples using various sites of local quartz

sand based on 50 wt% quartz sand and 30 wt% barium carbonate

The fifteen glass samples with 150 g weight in each sample were made

in the laboratory scale, using local quartz sand from 10 various sites such as Chanthaburi,

Trat, Rayong, Chumphon, Nakhon Si Thammarat, Pattani, Phuket, Songkhla, Nong Khai

and Tak provinces, and five samples from foreign countries such as Austria, Belgium,

Germany, Japan and U.S.A. The primary mixture contained 50 wt% quartz sand and 20

wt% mixture of sodium carbonate, potassium carbonate, calcium carbonate, aluminum

oxide, magnesium oxide, zinc oxide and boric oxide. 30 wt% barium carbonate was

added. All mixtures were melted in a ceramic crucible, in a normal atmosphere, at 1250

64

°C using an electric furnace with dwell time of 4 hrs, and cool down to room temperature.

The refractive index was measured using the refractometer.

The two glass samples with 150 g weight in each sample were

prepared with the same composition and melting process as above used quartz sand from

Tak and Belgium to compare the properties. The refractive index, density and hardness

were measured using refractometer, analytical balance and microhardness tester,

respectively.

3.3.1.2 Preparation of the glass samples using various concentrations of

local quartz sand from Chumphon site and barium carbonate

The twenty two glass samples with 150 g weight in each sample were

made using local quartz sand from Chumphon site added with various concentration of

barium carbonate ranging from 20, 22, 24, 26, 28, 30, 32, 34, 36, 38 and 40 wt%. They

were divided into two sets; added with 50 and 55 wt% local quartz sand. The primary

mixture contained quartz sand, dolomite, feldspar, limestone, sodium carbonate, and boric

oxide. They were melted in a ceramic crucible, in a normal atmosphere, at 1250°C using

an electric furnace with dwell time of 4 hrs, and cooled down to room temperature. The

density and the refractive index were measured by using the analytical balance and the

refractometer, respectively.

The five glass samples were fabricated using 50 wt% local quartz sand

with the same primary mixture and the melting process as above. They were added with

various concentrations of barium carbonate varying from 15, 25, 30, 35 and 45 wt%.

Phase identification was conducted by X-rays diffraction analysis using powder samples.

65

3.3.1.3 Comparison of properties of the prepared glass samples based on

local quartz sands from Chumphon added with sodium carbonate, lead oxide and

barium carbonate

The three glass samples with 150 g weight in each sample were made

with the primary composition of 50 wt% local quartz sand from Chumphon and 20 wt%

mixed of sodium carbonate, potassium carbonate, calcium carbonate, aluminum oxide,

magnesium oxide, zinc oxide and boric oxide. They were divided into three sets that

added with 30 wt% sodium carbonate, lead oxide and barium carbonate, respectively.

They were melted in a ceramic crucible, in a normal atmosphere, at 1250°C using an

electric furnace with dwell time of 4 hrs. The molten glasses were poured into a

cylindrical metal mould (3 cm in diameter and 5 cm in depth) and cooled down to room

temperature. The density and the refractive index were measured by using an analytical

balance and a refractometer, respectively. The hardness was measured by using a

microhardness tester in Knoop scale. The linear thermal expansion was also measured by

using a dilatometer.

3.3.1.4 Comparison of properties of the prepared glass samples based on

local quartz sand added with various kinds of barium compounds

The three glass samples with 150 g weight in each sample were made

with the primary composition of 50 wt% local quartz sand from Chumphon, 18 wt%


magnesium oxide, zinc oxide and boric oxide. They were divided into three sets that

added with 32 wt% different kinds of barium compounds; barium carbonate, barium

sulfate and local barite, respectively. They were melted in a ceramic crucible, in a normal

atmosphere, at maximum temperature 1200 to 1400°C using an electric furnace with

66

dwell time of 4 to 8 hrs, and cooled down to room temperature. The density and the

refractive index were measured using by an analytical balance and a refractometer,

respectively.


TiO2 based on local quartz sand from Chumphon site and barium carbonate

The fourteen glass samples with 150 g weight in each sample were

made with the primary composition of 50 wt% local quartz sand from Chumphon, 25

wt% mixture of sodium carbonate, potassium carbonate, calcium carbonate, aluminum

oxide, magnesium oxide, zinc oxide and boric oxide, and 25 wt% barium carbonate. They

were added with various concentration of titanium dioxide ranging from 1, 5, 10, 15, 25

and 30 wt%, respectively. They were melted in a ceramic crucible, in a normal

atmosphere, at maximum temperature 1250°C using an electric furnace with dwell time

of 8 hrs, and cooled down to room temperature. All specimens were prepared in parallel

with the normal lead containing glass and with the same concentration. The density and

the refractive index were measured using by an analytical balance and a refractometer,

respectively. Powder X-rays diffraction analysis was used to identify the phase of the

glass samples.


ZrO2 based on local quartz sand from Chumphon site and barium carbonate

The five glass samples with 150 g weight in each sample were made

with the primary composition of 55 wt% local quartz sand from Chumphon, 25 wt%

mixture of sodium carbonate, potassium carbonate, calcium carbonate, aluminum oxide,

magnesium oxide, zinc oxide and boric oxide, and 20 wt% barium carbonate. They were

added with various concentration of zirconium dioxide ranging from 0.5, 1, 1.5 and 5

67

wt%, respectively. They were melted in a ceramic crucible, in a normal atmosphere, at

maximum temperature 1250°C using an electric furnace with dwell time of 8 hrs, and

cooled down to room temperature. The density and the refractive index were measured

using by an analytical balance and a refractometer, respectively. Powder X-rays

diffraction analysis was used to identify the phase of the glass samples.


Bi2O3 based on local quartz sand from Chumphon site and barium carbonate

The seven glass samples with 150 g weight in each sample were made

with the primary composition of 30 mol% local quartz sand from Tak site, 5 mol%

mixture of sodium carbonate, potassium carbonate, calcium carbonate, aluminum oxide,

magnesium oxide, zinc oxide and boric oxide. They were added with various

concentration of bismuth oxide varying from 25 to 60 mol%, respectively. They were

melted in a ceramic crucible, in a normal atmosphere, at maximum temperature 1150°C

using an electric furnace with dwell time of 4 hrs. The molten glasses were poured into a

cylindrical metal mould (3 cm in diameter and 5 cm in depth) and cooled down to room

temperature. The density and the refractive index were measured using by an analytical

balance and a refractometer, respectively. The electric conductivity was measured in

order to calculate the dielectric constant. The glass samples were polished on both sides,

and colloidal silver paint was used as the electrodes. The capacitance was measured using

a LCR meter.

3.3.2 Colored glass sample preparation

The colorless lead-free high refractive index glass samples were prepared into

seven samples in the laboratory scale. The glass mixtures contained local raw materials

from various sites; quartz sand (SiO2) from Tak, dolomite (CaMgCO3) from

68

Kanchanaburi, feldspar (KAlSi3O8) from Ratchaburi and limestone (CaCO3) from Phrae,

and reagent-grade Na2CO3, B2O3 and BaCO3. The glass-forming composition was

represented by the following generic formula (mol%);

55SiO2.13Na2CO3.5B2O3.14BaCO3.2CaMgCO3.1KAlSi3O8.10CaCO3.

Prior to melting, colorants were added to produce colors in glass samples; 7.0 wt% CuO,

0.5 wt% CoO, 1.75 wt% Cr2O3, mixture of 4.0 wt% CuO and 2.0 wt% Fe2O3, 4.0 wt%

Fe2O3, and mixture of 0.2 wt% Au metal and 2.5 wt% Se powder. Well-mixed and dried

powders mixtures were melted in a ceramic crucible, in a normal atmosphere, in an

electric furnace, at 1250 ºC for 4 hours. The melted glasses were removed from the

furnace and poured into a cylindrical metal mould (3 cm in diameter and 5 cm in depth)

and cooled down to room temperature. The transparent and bubbles-free glass samples

were obtained and polished before properties measurements. The refractive index was

determined from the polished glass samples using a refractometer. The density of the

samples was measured in water by the Archimedean buoyancy method, using an

analytical balance. The absorption spectra were recorded by the UV-Vis-NIR

spectrophotometer. The composition of the glass samples were analyzed using Proton

Induced X-ray Emission (PIXE) analysis.

3.3.3 Red colored glass sample preparation

3.3.3.1 Gold ruby glass sample

The nine lead free glass samples were prepared in the laboratory scale.

The glass sample with 150 g weight each was made with the primary glass mixture

contained with local sand from Tak (the by-product from feldspar floatation plant),

carbonates of barium, potassium, and sodium, and boric oxide. Gold metal and selenium

powder were added into the primary glass as the colorant. Well-mixed and dried powders

69

mixture was melted in a compound crucible, in an electric furnace, at the maximum

temperature of 1250°C for 4 hr dwelling time, poured into a plate metal mould (3x3x1

cm), and then cooled down to room temperature.

The color descriptions were carried out using the Color portable set.

Prior to measure the refractive index, the glass samples were cut into many small pieces

that were mounted in epoxy resin and the surface was ground and then polished to a

mirror finish with a 0.3 µm alumina paste. Refractive indices were determined using a

refractometer. The absorption spectrum was recorded by UV-Vis-NIR spectrophotometer.

3.3.3.2 Selenium ruby glass sample

The lead free glass samples were prepared in the laboratory scale. The

seven glass samples with 150 g weight each were made with the primary glass mixtures

with the refractive index of 1.542 that contained with local sand from Tak Province (the

by-product from feldspar floatation plant), BaCO3, K2CO3, Na2CO3, CaCO3, Al2O3, and

B2O3. Se and CdS were added into the primary glass as the colorant. The concentration of

CdS was fixed at 1 wt% and the ratios of Se and CdS were varied as 1:1, 2:1, 4:1, 6:1,

8:1, and 10:1. Well-mixed and dried powders mixtures were melted in a ceramic crucible,

in an electric furnace, at the maximum temperature of 1250°C for 4 hr dwelling time,

poured into a cylindrical metal mould (3 cm in diameter and 5 cm in depth), and then

cooled down to room temperature.

The color descriptions were carried out using the Color portable set. The

density of the glass samples was measured in water by the Archimedean buoyancy

method, using an analytical balance. Prior to measure the refractive index, the surface of

the glass samples was ground and then polished to a mirror finish with a 0.3 µm alumina

70

paste. Refractive indices were determined using a refractometer. The absorption spectrum

was recorded by UV-Vis-NIR spectrophotometer.

3.3.3.3 Comparison of properties of red colored glass samples

The four red colored glass samples were selected. The first sample was

the Ancient Thai Glass. The second one was the lead glass that prepared from the glass

mixture which doped with gold metal and selenium powder to obtain the refractive index

closed to that of the Ancient Thai Glass. The third and the last ones were the samples

selected from 3.3.3.1 and 3.3.3.2 that gave the best tone of color, respectively. The

refractive index and the peak positions were discussed.

3.3.4 Colorless glass sample preparation in the higher scales

The stoichiometric compositions of the batch materials; 15 and 225 kg were

prepared in the pilot scale based on 50 wt% quartz sand from Chumphon and 18 wt%


magnesium oxide, zinc oxide and boric oxide that added with 32 wt% barium carbonate.

The mixture were melted in a compound clay crucible, using a gas furnace at the

maximum temperature of 1400 °C and soaking time of 10 and 14 hr, respectively. At the

complete melting, a molten glass was removed and blown into a cylindrical steel mould

(10 cm in diameter and 30 cm in depth) with the glass-blowing pipe to obtain a

cylindrical shape. The other one was poured into a sheet mould (30x30x5 cm) to make a

plate glass.

3.3.5 Colorless decorative glass sample preparation

The three glass samples with 150 g weight and the glass sample with 15 kg

weight in each sample were made in the laboratory and the higher scales, respectively.

The three samples of the primary composition of the local quartz sand from Chumphon,

71

dolomite, feldspar, limestone, sodium carbonate, potassium carbonate and boric oxide

added with 30 wt% barite, soda ash and lead oxide, respectively. The mixtures were

melted in a ceramic crucible in the normal atmosphere, at 1250°C using an electric

furnace, and then cooled down to room temperature. The refractive index was measured

using a refractometer. The last sample with the same composition as in the laboratory

scale were prepared and melted in normal atmosphere, at 1350 °C using a gas furnace

with 14 hours dwelling time. The molten glass was blown into a cylindrical shape (10 cm

in diameter and 30 cm in depth) with a mount glass-blowing pipe, cut into many small

sheets and then coated on one side by silvering method. The joining interfacial layer

between the glass body and the mirror coating layer was studied using a SEM. The

refractive indices of the four types of colorless decorated glasses; Ancient Thai Glass,

imported modern glass, lead-bearing glass and barium-bearing glass were comparatively

measured.

3.3.6 Glass jewelry sample preparation

The optical property of the glass jewelry that imported from foreign countries

such as Austria, China and Germany was determined by using a refractometer.

The prepared colored glasses from 3.3.2 were cut, grinded and polished in

order to make as the glass jewelry.

Furthermore, to examine the dielectric constant of the doped glass samples, the

barium-bearing glass samples whose main compositions are of local quartz sand and

barite were prepared. About 150 g of 6 glass samples prepared in the laboratory scale was

made primarily with glass mixture of quartz sand from Tak and barite from Loei, north

and northeastern provinces of Thailand, respectively, together with mixtures of sodium-

and potassium carbonates, and boric oxide. An undoped, therefore colorless, Ba-based

72

glass is taken as a reference sample. Oxides of manganese, iron, copper, neodymium and

erbium were added to the raw glass mixture as different colorants. The detailed

composition of each sample is shown in Table 3.1. The raw mixtures were melted in a

ceramic crucible, using an electric furnace, in normal ambient atmosphere, and soaked at

a maximum temperature of 1250°C with dwelling time of 4 hrs. After complete melting,

the molten glass was cooled down to room temperature. The resulted glass samples

appeared homogeneous in colors and free of bubbles.

The parallel plate contacting electrode method was used for the dielectric

constant measurements. Dielectric test fixtures for capacitance measurement using a LCR

meter.

Conventional metallographic techniques were used to prepare the glass

samples prior to the refractive index and the optical absorption measurements. After

being mounted in epoxy resin, the glass surfaces were ground and polished with fine

alumina paste down to less than 0.3 µm in roughness. Refractive indices were determined

using a refractometer. The absorption spectra were recorded by UV-Vis-NIR

spectrophotometer. The color descriptions of the glass samples were carried out using a

color portable set.

73

Table 3.1 Composition of barium-baring glass samples with different dopants.

Composition (wt %)

Sample

name Quartz sand Barite Na2CO3+

K2CO3 +B2O3

Mn2O3 Fe2O3 CuO Nd2O3 Er2O3

Ba 50 30 20 - - - - -

Ba-Mn 50 30 20 1.5 - - - -

Ba-Fe 50 30 20 - 2.0 - - -

Ba-Cu 50 30 20 - - 1.0 - -

Ba-Nd 50 30 20 - - - 2.5 -

Ba-Er 50 30 20 - - - - 2.5

3.3.7 Radiation shielding glass sample preparation

3.3.7.1 Gamma radiation at 356 keV

The cylindrical colorless lead free glass samples were prepared into

eight samples in the laboratory scale. The glass mixtures contained 150 g weight in each

sample. The content of Chumphon sand was fixed at 40 % (by weight) as a main

composition but concentrations of barium carbonate were varied from 6 to 30 % (by

weight), respectively. Well-mixed and dried powders mixtures were put in a ceramic

crucible. The crucibles were then melted in an electric furnace, in normal atmosphere at

1250°C with 4 h dwelling time. All samples were prepared in parallel with the lead glass

and with the same concentrations. After the complete melting, the molten glasses were

removed, poured into a cylindrical steel mould; 3 cm in diameter and 1 cm in thickness,

74

and then cooled down to room temperature. The transparent and bubbles-free cylindrical

glass samples were obtained.

The gamma attenuation characteristics of the prepared lead free glasses

have been studied for photon in the energy at 356 keV about 5 µCi Ba-133; a

monoenergetic gamma radiation source that was procured as a sealed source. The gamma

radiation transmission measurements were done under a narrow beam counting geometry

employing the NaI(Tl) detector with the scaler. The samples having various

concentrations of BaCO3 were interposed in the beam. The counts under the full energy

absorption peak of the recorded photon spectrum were determined.

3.3.7.2 Gamma radiation at 662 keV

The colorless lead-free high refractive index glass samples were

prepared into eleven samples in the laboratory scale. The system was (Na2O,K2O)-BaO-

CaO-MgO-B2O3–SiO2. Batches with 150 g weight in each sample were contained with

the 40 wt% dressed quartz sand from Tak Province; from feldspar floatation plant, boric

oxide, carbonates of sodium, calcium and potassium, and adding concentration of barium

carbonate varied from 20 to 40 wt%, respectively. The glasses mixtures were melted in an

electric furnace, in normal atmosphere at 1250°C with 4 h dwelling time. After the

complete melting, the molten glasses were removed, poured into a cylindrical steel

mould; 3 cm in diameter and 1 cm thick, and then cooled down to room temperature. The

transparent and bubbles-free cylindrical glass samples were obtained.

The gamma attenuation characteristics of the prepared lead free

glasses have been studied for photon in the energy range of 662 keV. The monoenergetic

gamma radiation used for these measurements was derived from Cs-137 of about 5 µCi

that was procured as a sealed source. The gamma radiation transmission measurements

75

were done under a narrow beam counting geometry employing the NaI(Tl) detector with

the scaler. The lead free glass samples having various concentrations of BaCO3 were

interposed in the beam. The counts under the full energy absorption peak of the recorded

photon spectrum were determined. The attenuation coefficients were calculated and

compared with those of previous works.

Documents

EXPERIMENTAL PROCEDURES - Chiang Mai University