Related Experiment Video
Updated: Jan 31, 2026
06:58
Electrochemical Etching and Characterization of Sharp Field Emission Points for Electron Impact Ionization
Published on: July 12, 2016
10.0K
Dosimetric characterization of a large area pixel-segmented ionization chamber
S Amerio1, A Boriano, F Bourhaleb
1A.O.S. Giovanni Battista, Presidio S. Giovanni A.S., Via Cavour 31, 1-10100 Torino, Italy.
Medical Physics
|March 6, 2004
Summary
A novel pixel-segmented ionization chamber offers efficient 2D dosimetry for complex radiation fields. This detector provides accurate measurements, significantly reducing verification time for medical radiation therapy.
Area of Science:
- Medical Physics
- Radiation Detection and Measurement
Background:
- Traditional dosimetry methods struggle with complex radiation fields.
- Accurate two-dimensional (2D) dose verification is crucial in modern radiotherapy.
Purpose of the Study:
- To design and characterize a pixel-segmented ionization chamber for 2D dosimetry.
- To evaluate the detector's performance with complex radiation fields and large gradients.
Main Methods:
- A pixel-segmented ionization chamber with 1024 independent chambers was developed.
- Detector characterization involved 60Co and 6 MV x-ray beams in a PMMA phantom.
- Performance metrics included linearity, sensitivity, charge collection efficiency, and comparison with a Farmer chamber.
Main Results:
- The detector demonstrated good signal linearity with dose and dose rate.
- Average sensitivity was 2.1 nC/Gy, stable over a month.
- Charge collection efficiency was 0.985 at operating voltage.
- Comparisons with a Farmer chamber showed good agreement for tissue maximum ratio and output factors.
Conclusions:
- The pixel-segmented ionization chamber is suitable for 2D dosimetry of x-ray photon beams.
- It offers good spatial resolution and significantly reduces dosimetric verification time.
- This technology aids in the precise verification of complex radiation fields in radiotherapy.
More Related Videos
Related Concept Videos
01:08Matrix-Assisted Laser Desorption Ionization (MALDI)
1.2K
Matrix-assisted laser desorption ionization (MALDI) is a powerful analytical technique used in mass spectrometry. It enables the identification and characterization of various biomolecules, including proteins, peptides, nucleic acids, and carbohydrates. MALDI is an ionization technique, widely employed in biological and medical research, as well as in fields like pharmacology and biochemistry.The analyte of interest, a biomolecule or a mixture of biomolecules, is mixed with a suitable matrix...
1.2K
01:16Chambers of the Heart
10.5K
The human heart is a complex organ made up of four chambers: the right and left atria and the right and left ventricles. These internal chambers are separated by partitions known as the interatrial and interventricular septa. The exterior of the heart features a groove known as the coronary sulcus that demarcates the atria from the ventricles, while the anterior and posterior interventricular sulci distinguish between the two ventricles.
Deoxygenated blood from the body is received in the right...
Deoxygenated blood from the body is received in the right...
10.5K
03:12Ionization Energy
43.3K
The amount of energy required to remove the most loosely bound electron from a gaseous atom in its ground state is called its first ionization energy (IE1). The first ionization energy for an element, X, is the energy required to form a cation with 1+ charge:
43.3K
01:21Chemical Ionization (CI) Mass Spectrometry
1.5K
The molecular ion peak of a molecule in the mass spectrum provides vital information for molecular identification. However, conventional electron impact ionization can lead to the rapid dissociation of some molecular ions before they reach the detector. A milder ionization method is required to increase the lifetime of such ionized analyte molecules. Chemical ionization (CI) is a gas-phase protonation reaction useful for mass-analyzing analyte molecules that are easily protonated to yield the...
1.5K
01:12Electrospray Ionization (ESI) Mass Spectrometry
2.3K
Higher molecular weight biomolecules are nonvolatile compounds that may decompose before ionizing or vaporizing during mass analysis with conventional electron impact ionization methods. Accordingly, electrospray ionization (ESI) is the favored method for vaporizing and ionizing biomolecules as it circumvents rapid fragmentation and enables the recording of mass signals for the entire biomolecule.
ESI utilizes electrical energy to transfer ions from the liquid phase of the sample into the...
ESI utilizes electrical energy to transfer ions from the liquid phase of the sample into the...
2.3K
02:08Titration of a Polyprotic Acid
105.2K
A polyprotic acid contains more than one ionizable hydrogen and undergoes a stepwise ionization process. If the acid dissociation constants of the ionizable protons differ sufficiently from each other, then the titration curve for such polyprotic acid generates a distinct equivalence point for each of its ionizable hydrogens. Therefore, titration of a diprotic acid results in the formation of two equivalence points, whereas the titration of a triprotic acid results in the formation of three...
105.2K