Estimating the Half Layer Value for Aluminum and Wood - Lab Report Example

Half value layer is often applied in radiography, this is because it is easier to remember or recall the values and simple calculations are readily performed. There are often multiple factors the affect half-value layer. These factors often bring the difference in the value of HVL in different materials. For the case of aluminum, the following factors always affect HVL. The thickness of the aluminum attenuator, purity of the aluminum, detector material of dosimeter used. Fluctuation of x-ray output, detector location in x-ray field. Ultra-high purity of aluminum always produces more accurate measures of half-value layer (Edenman and Sidney). This is often different from aluminum alloys since they have got a lot of impurities available. Although the half value of different materials was one of the important parameters for Quality assurance and Quality control, constant monitoring had not been performed because of measurement using the process of the ionization chamber.

1) A piece of wood
This is a porous and fibrous structural tissue always found in the stems and even roots of trees.
2) A piece of aluminum board
Aluminum is the second most metallic element. It always ways about 1/3 as much as copper. Aluminum is always reactive and chemically occurs in nature.
3) Sr – 90 (strontium)
4) Cs – 137 (cesium)
5) Caliper
6) Geiger mutter meter
Methodology
1) Data were collected using a Geiger meter.
2) The ion chamber was placed on the table and the tube rotation was disabled.
3) Data for all the systems was collected on the same system.
4) The chamber was displaced from the isocenter which changes the half-value layer.

Different materials have got different half-value layers. This brings the difference in capability in shielding of the same material. As can be seen from the table above wood have the highest half value than aluminum. The value of wood was 6.00mm while that of aluminum was 1.6mm. Half value layer was the most used factor for describing both the penetrating ability and the penetration through specific objects or material. Different shielding strengths of different objects also differ when different materials are used. This is evident from the first table, the Sr is different for both the aluminum and wood.

Conclusion
There are often multiple factors the affect half-value layer. These factors often bring the difference in the value of HVL in different materials. For the case of aluminum, the following factors always affect HVL. The thickness of the aluminum attenuator, purity of the aluminum. These factors are often the source of errors when carrying out the experiment. For example, when the aluminum alloy was used it may have some impurities affecting HVL. The experiment can be improved by using pure aluminum.