SU-E-I-24: Design and Fabrication of a Multi-Functional Neck and Thyroid Phantom for Medical Dosimetry and Calibration

2014 ◽  
Vol 41 (6Part5) ◽  
pp. 135-135
Author(s):  
S Mehdizadeh ◽  
S Sina ◽  
M Karimipourfard ◽  
F Lotfalizadeh ◽  
R Faghihi ◽  
...  
Keyword(s):  
Medical Dosimetry ◽  
Thyroid Phantom

Design and fabrication of a multipurpose thyroid phantom for medical dosimetry and calibration

2015 ◽  
Vol 168 (4) ◽  
pp. 503-508 ◽  
Author(s):  
Simin Mehdizadeh Naderi ◽  
Sedigheh Sina ◽  
Mehrnoosh Karimipoorfard ◽  
Fatemeh Lotfalizadeh ◽  
Mohammad Entezarmahdi ◽  
...  
Keyword(s):  
Medical Dosimetry ◽  
Thyroid Phantom

Probing The Transient Response To Improve The Stability Of Diamond Devices Under Pulsed Periodic Excitation

2007 ◽  
Vol 1039 ◽  
Author(s):  
Philippe Bergonzo ◽  
Hassen Hamrita ◽  
Dominique Tromson ◽  
Caroline Descamps ◽  
Christine Mer ◽  
...  
Keyword(s):  
Polycrystalline Diamond ◽  
Pulse Generation ◽  
Uniform Electric Field ◽  
Device Stability ◽  
Photon Pulse ◽  
History Of ◽  
Medical Dosimetry ◽  
The Stability ◽  
Detection Characteristics ◽  
Time Of Flight Spectroscopy

AbstractCVD diamond combines attractive properties for the fabrication of detection devices operating in specific environments. One problem that remains critical for device stability is the presence of defect levels that alter the detection performances, and the detection characteristics often appear as they are very depending on time, temperature, and history of the preceding irradiations.One issue we have proposed is to adapt one technique that is commonly used for time of flight spectroscopy in order to maintain a uniform electric field in the probed device, and based on the synchronisation of the device bias with the period of the excitation source. This can be applied to several types of detection applications, as long as we can rely on periodical triggering in order to synchronise the device polarisation. We apply it here to a LINAC electron accelerator used for photon pulse generation at the frequency of 25Hz. The result is a remarkable improvement of the performance of a polycrystalline diamond detector that exhibits a particularly defective response when used in the steady state excitation, to reach that of a perfectly stable and reproducible device response in the pulsed mode. We claim this method to be applicable to several types of excitations and particularly to present a high interest for monitoring accelerator sources, e.g. for medical dosimetry applications.

scholarly journals The Effect of Ionising Radiation on the Luminescence Properties of Fluoroperovskites

2021 ◽  
Author(s):  
◽  
Joseph Schuyt
Keyword(s):  
Energy Levels ◽  
Thermal Quenching ◽  
Ionising Radiation ◽  
Luminescence Properties ◽  
Readout System ◽  
Tissue Equivalent ◽  
Potential Applications ◽  
Radiation Induced ◽  
Medical Dosimetry ◽  
Physical Phenomena

<p>The luminescence of crystalline compounds can be used to monitor many physical phenomena, including doses of ionising radiation. Optically stimulated luminescence (OSL), thermoluminescence (TL), and radiophotoluminescence (RPL) have been successfully employed in dosimetry. However, few materials possess both the structural and luminescence properties required for medical dosimetry. This thesis aimed to investigate the luminescence features of the class of compounds known as fluoroperovskites. Emphasis was placed on studying the effects of irradiation on the luminescence properties, such that the compounds could be evaluated regarding potential applications in clinical dosimetry. Samples were primarily characterised using photoluminescence (PL), radioluminescence (RL), OSL, RPL, TL, and transmittance spectroscopy.  OSL was observed in the majority of samples due to the existence of electron trapping F-type centres. F-centre/Mn complexes were observed in all AMgF3:Mn compounds after irradiation and the energy levels of the complexes in each compound were experimentally determined. The most promising potential dosimeter host material was the near tissue-equivalent NaMgF3. When doped with Mn2+, the compound exhibited RPL via the formation of F-centre/Mn complexes and OSL via several trapping centres. The RPL could be probed independently to the OSL such that the compound could function as a hybrid OSL/RPL dosimeter. In the NaMgF3:Ln compounds, RPL occurred via the radiation-induced reduction Ln3+ → Ln2+ for Ln = Sm, Dy, and Yb. The reduction Sm3+ → Sm2+ was highly stable and could be non-destructively probed independently to the OSL. The Sm doped compound also exhibited radiation-induced conductivity that could be coupled with the RL, such that the compound could function as a real-time hybrid optical/electrical dosimeter. Charge kinetics, thermal quenching, and binding energy models were developed and applied to the compounds.   Finally, a two-dimensional readout system was designed and constructed. The capabilities of the system were evaluated using the OSL of NaMgF3:Eu and NaMgF3:Mn. Sensitivities to doses from < 10 mGy to > 1 Gy were obtained along with sub-millimetre spatial resolutions.</p>

The suitability of different preparations of thermoluminescent lithium borate for medical dosimetry

1982 ◽  
Vol 27 (8) ◽  
pp. 1023-1034 ◽  
Author(s):  
B F Wall ◽  
C M H Driscoll ◽  
J C Strong ◽  
E S Fisher
Keyword(s):  
Lithium Borate ◽  
Medical Dosimetry

scholarly journals Optically Stimulated Nanodosimeters with High Storage Capacity

Nanomaterials ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 1127 ◽  
Author(s):  
David Van der Heggen ◽  
Daniel R. Cooper ◽  
Madeleine Tesson ◽  
Jonas J. Joos ◽  
Jan Seuntjens ◽  
...  
Keyword(s):  
Storage Capacity ◽  
Infrared Light ◽  
X Rays ◽  
High Storage Capacity ◽  
Uniform Solution ◽  
Bright Green ◽  
Medical Dosimetry ◽  
Coprecipitation Route ◽  
Shallow Traps ◽  
High Storage

In this work we report on the thermoluminescence (TL) and optically stimulated luminescence (OSL) properties of β-Na(Gd,Lu)F4:Tb3+ nanophosphors prepared via a standard high-temperature coprecipitation route. Irradiating this phosphor with X-rays not only produces radioluminescence but also leads to a bright green afterglow that is detectable up to hours after excitation has stopped. The storage capacity of the phosphor was found to be (2.83 ± 0.05) × 1016 photons/gram, which is extraordinarily high for nano-sized particles and comparable to the benchmark bulk phosphor SrAl2O4:Eu2+,Dy3+. By combining TL with OSL, we show that the relatively shallow traps, which dominate the TL glow curves and are responsible for the bright afterglow, can also be emptied optically using 808 or 980 nm infrared light while the deeper traps can only be emptied thermally. This OSL at therapeutically relevant radiation doses is of high interest to the medical dosimetry community, and is demonstrated here in uniform, solution-processable nanocrystals.

Thyroid Phantom Differential Attenuation Contribution to Thyroid Uptake Values

1998 ◽  
Vol 23 (2) ◽  
pp. 133
Author(s):  
W. W. Mohr ◽  
T. Orlando ◽  
J. Mack ◽  
R. Worrells ◽  
S. Dadparvar
Keyword(s):  
Thyroid Uptake ◽  
Thyroid Phantom
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