Energy resolution for accurate measurements of the X-ray linear attenuation coefficient

2006 ◽  
Vol 75 (9) ◽  
pp. 936-944 ◽  
Author(s):  
S. Midgley
Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2212
Author(s):  
Worawat Poltabtim ◽  
Ekachai Wimolmala ◽  
Teerasak Markpin ◽  
Narongrit Sombatsompop ◽  
Vichai Rosarpitak ◽  
...  

The potential utilization of wood/polyvinyl chloride (WPVC) composites containing an X-ray protective filler, namely bismuth oxide (Bi2O3) particles, was investigated as novel, safe, and environmentally friendly X-ray shielding materials. The wood and Bi2O3 contents used in this work varied from 20 to 40 parts per hundred parts of PVC by weight (pph) and from 0 to 25, 50, 75, and 100 pph, respectively. The study considered X-ray shielding, mechanical, density, water absorption, and morphological properties. The results showed that the overall X-ray shielding parameters, namely the linear attenuation coefficient (µ), mass attenuation coefficient (µm), and lead equivalent thickness (Pbeq), of the WPVC composites increased with increasing Bi2O3 contents but slightly decreased at higher wood contents (40 pph). Furthermore, comparative Pbeq values between the wood/PVC composites and similar commercial X-ray shielding boards indicated that the recommended Bi2O3 contents for the 20 pph (40 ph) wood/PVC composites were 35, 85, and 40 pph (40, 100, and 45 pph) for the attenuation of 60, 100, and 150-kV X-rays, respectively. In addition, the increased Bi2O3 contents in the WPVC composites enhanced the Izod impact strength, hardness (Shore D), and density, but reduced water absorption. On the other hand, the increased wood contents increased the impact strength, hardness (Shore D), and water absorption but lowered the density of the composites. The overall results suggested that the developed WPVC composites had great potential to be used as effective X-ray shielding materials with Bi2O3 acting as a suitable X-ray protective filler.


2018 ◽  
Vol 91 (1087) ◽  
pp. 20180139 ◽  
Author(s):  
Mark Worrall ◽  
Sarah Vinnicombe ◽  
David G Sutton

Objective: This work presents a proof of principle for a method of estimating the thickness of an attenuator from a single radiograph using the image, the exposure factors with which it was acquired and a priori knowledge of the characteristics of the X-ray unit and detector used for the exposure. It is intended this could be developed into a clinical tool to assist with paediatric patient dose audit, for which a measurement of patient size is required. Methods: The proof of principle used measured pixel value and effective linear attenuation coefficient to estimate the thickness of a Solid Water attenuator. The kerma at the detector was estimated using a measurement of pixel value on the image and measured detector calibrations. The initial kerma was estimated using a lookup table of measured output values. The effective linear attenuation coefficient was measured for Solid Water at varying kVp. 11 test images of known and varying thicknesses of Solid Water were acquired at 60, 70 and 81 kVp. Estimates of attenuator thickness were made using the model and the results compared to the known thickness. Results: Estimates of attenuator thickness made using the model differed from the known thickness by 3.8 mm (3.2%) on average, with a range of 0.5–10.8 mm (0.5–9%). Conclusion: A proof of principle is presented for a method of estimating the thickness of an attenuator using a single radiograph of the attenuator. The method has been shown to be accurate using a Solid Water attenuator, with a maximum difference between estimated and known attenuator thickness of 10.8 mm (9%). The method shows promise as a clinical tool for estimating abdominal paediatric patient thickness for paediatric patient dose audit, and is only contingent on the type of data routinely collected by Medical Physics departments. Advances in knowledge: A computational model has been created that is capable of accurately estimating the thickness of a uniform attenuator using only the radiographic image, the exposure factors with which it was acquired and a priori knowledge of the characteristics of the X-ray unit and detector used for the exposure.


Author(s):  
M. U. Mgbukwu ◽  
L. D. Christopher ◽  
A. J. Iseh

This study analyses the linear attenuation coefficient as an indicator for safe water, the study was carried out using various water samples from borehole, well and pond in two Local Government Areas namely, Jos North and Jos East areas of Plateau State, Nigeria. The samples were collected in a Perspex of volume 7cmX7cmX7cm and filled to a height of 3cm. Energy of 70kVp of X-ray was passed through the samples with an X-ray detector under the Perspex of water to get the different final X-ray doses. From the study the linear attenuation coefficient ranges from 0.2878cm-1-0.4270cm-1, 0.3074cm-1-0.4743cm-1, 0.3074cm-1-0.4743cm-1 for borehole, well and pond in that order. The study showed a strong correlation between the linear attenuation coefficient and turbidity, total hardness and density which follows a trend for different samples. The highest value of linear attenuation ranges from borehole, well, pond in that order. This study was able to get a value of linear attenuation coefficient for safe water which ranges from 0.40203cm-1-0.02414cm-1 which can be used to ascertain the quality of water.


2019 ◽  
Vol 160 ◽  
pp. 89-95 ◽  
Author(s):  
Audrew Frimaio ◽  
Bruna C. Nascimento ◽  
Ramon M.M. Barrio ◽  
Leticia L. Campos ◽  
Paulo R. Costa

Author(s):  
Ahmed Jassim Mohammed, Riad Manadi Ramadan, Raed Muslim Shab

In this research, Calculation the Attenuation of X-ray radiation for low density polyethylene composites with oyster shells powder (extracted from the Caspian Sea in Iran), low density polyethylene production in the form of powder by the State Company for Petrochemical Industries (Basra-Iraq), the range of the added of oyster shells powder (extracted from the Caspian sea in Iran) has the values (0%, 2.5%, 5%, 10%, 15%, 20%, and 25%) for low density polyethylene weight and the added oyster shells powder with the particular size (≤ 250 μm). were investigated through several variables, such as, linear attenuation coefficient(μ) and mean free path(λ). The obtained results were appeared that the added oyster to reduce the spaces between the polymer chains, which reflects the high ability of the polymer as (10%-20%), and this increase will give further property that increase the attenuation x-ray of the prepared specimens. Where the practical study and the beam of intensity of energy (30 kv) and)VG.M = 600 voit(. The results showed that when increasing filler content, the total linear attenuation coefficient increases while the mean free path decreases. The mean free path (λ) at (2.5%) is (2.1 cm (, while at (20%) is (0.40 cm). The value of the linear attenuation coefficient (μ) at (20%) is)2.44 cm-1(, while at (2.5%) is) 0.49 cm-1(.


2019 ◽  
Vol 7 (2B) ◽  
Author(s):  
LILIANE Aparecida SILVA ◽  
Adriana Batistab ◽  
Jefferson Nascimentoc ◽  
Clascidia Furtadoc ◽  
Luiz Faria

Polymeric materials can serve as a matrix for the dispersion of nanomaterials with good attenuation features, resulting in lightweight, conformable, flexible, lead-free and easy-to-process materials. Thus, some well-known radiation shielding materials could be used in low proportion as a filler, for the formation of new materials. On the other hand, nanostructured carbon materials, such as graphene oxide (GO) have been reported recently to show enhanced attenuation properties. For the present work, poly(vinylidene fluoride) [PVDF] homopolymers and its fluorinated copolymers were filled with metallic oxides and nanosized reduced graphene oxides (rGO) in order to produce nanocomposites with increased low energy X ray attenuation efficiency. We objective is to investigate the X ray shielding features of multilayered PVDF/rGO and P(VDF-TrFE)/BaO composites. PVDF/rGO overlapped with P(VDF-TrFE)/BaO thin films were sandwiched between two layers of kapton films of different thickness. The linear attenuation coefficients were measured for monochromatic X ray photons with energy of 8.1 keV. The samples were characterized by Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), Ultraviolet–visible (UV-vis) and Fourier-Transform Infrared (FTIR) Spectroscopy. The linear attenuation coefficient of the multilayered sample was evaluated and compared with the linear attenuation of the individual constituents. It was observed an increase in the attenuation coefficient of the overlapping samples. It is demonstrated that thin films of rGO nanocomposite with thickness of only 0.32 mm can attenuate up to 50% of X ray beams with energy of 8.1 keV, justifying further investigation of these nanocomposites as X ray or gamma radiation attenuators


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