scholarly journals Simultaneous Measurements of Dose and Microdosimetric Spectra in a Clinical Proton Beam Using a scCVD Diamond Membrane Microdosimeter

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1314
Author(s):  
Oluwasayo Loto ◽  
Izabella Zahradnik ◽  
Amelia Maia Leite ◽  
Ludovic De Marzi ◽  
Dominique Tromson ◽  
...  
Keyword(s):  
Proton Therapy ◽  
Beam Quality ◽  
Pulse Height ◽  
Chemical Vapor ◽  
Silicon On Insulator ◽  
Dose Profile ◽  
Simultaneous Measurements ◽  
Tissue Equivalent ◽  
Set Up ◽  
D Values

A single crystal chemical vapor deposition (scCVD) diamond membrane-based microdosimetric system was used to perform simultaneous measurements of dose profile and microdosimetric spectra with the Y1 proton passive scattering beamline of the Center of Proton Therapy, Institute Curie in Orsay, France. To qualify the performance of the set-up in clinical conditions of hadrontherapy, the dose, dose rate and energy loss pulse-height spectra in a diamond microdosimeter were recorded at multiple points along depth of a water-equivalent plastic phantom. The dose-mean lineal energy (y¯D) values were computed from experimental data and compared to silicon on insulator (SOI) microdosimeter literature results. In addition, the measured dose profile, pulse height spectra and y¯D values were benchmarked with a numerical simulation using TOPAS and Geant4 toolkits. These first clinical tests of a novel system confirm that diamond is a promising candidate for a tissue equivalent, radiation hard, high spatial resolution microdosimeter in beam quality assurance of proton therapy.

Resistless Patterning of Magnetic Storage Media Using Ion Projection Structuring

2001 ◽  
Vol 705 ◽  
Author(s):  
A. Dietzel ◽  
R. Berger ◽  
H. Grimm ◽  
C. Schug ◽  
W. H. Bruenger ◽  
...  
Keyword(s):  
Process Development ◽  
Ion Beam ◽  
Silicon On Insulator ◽  
Magnetic Storage ◽  
Magnetic Islands ◽  
Superlattice Structure ◽  
Head Positioning ◽  
Out Of Plane ◽  
Set Up ◽  
The Impact

AbstractCo/Pt thin film multilayers with strong perpendicular anisotropy and out-of-plane coercivities of 5-11 kOe were magnetically altered in areas of local ion beam interaction. The ion irradiations were performed by ion projection through silicon stencil masks fabricated by silicon on insulator (SOI) membrane technology. The ion projector at the Fraunhofer Institute for Silicon Technology (ISiT) was operated at 73 keV ion energy and with a 8.7- fold demagnification. After exposure to 3 × 1014Ar+/ cm2 magnetic islands smaller than 100 nm in diameter were resolved in the Co/Pt multilayersby means of magnetic force microscopy. The impact of different ion species (He+, Ar+ and Xe+) and ion energies (10 – 200 keV) on the multilayer structure was evaluated using Monte Carlo simulations. The ballistic interface intermixing was used to predict magnetic coercivity changes for various irradiation conditions. The simulations revealed that with 73 keV Ar+ and Xe+ ions the irradiation dose could be reduced by a factor of 100 and 400 respectively in comparison to 73 keV He+which was verified in the experiments. X-ray reflectivity measurements confirmed that the Co/Pt superlattice structure is slightly weakened during the irradiation and that the surface smoothness of the media is preserved. Using the Ion Projection Process Development Tool (PDT) at IMS-Vienna concentric data tracks including head positioning servo informations were patterned onto a 1” IBM microdrive™ glass disk which was coated with Co/Pt multilayers. In a single exposure step several tracks within an exposure field of 17 mm in diameter were structured by 2 × 1015He+/ cm2 at 45 keV using a 4- fold demagnification set-up.

scholarly journals A large area diamond-based beam tagging hodoscope for ion therapy monitoring

2018 ◽  
Vol 170 ◽  
pp. 09005 ◽  
Author(s):  
M.-L. Gallin-Martel ◽  
L. Abbassi ◽  
A. Bes ◽  
G. Bosson ◽  
J. Collot ◽  
...  
Keyword(s):  
Detection Efficiency ◽  
Signal To Noise Ratio ◽  
Therapy Monitoring ◽  
Chemical Vapor ◽  
X Rays ◽  
Reaction Products ◽  
Large Area ◽  
Position Measurement ◽  
Set Up ◽  
Good Signal

The MoniDiam project is part of the French national collaboration CLaRyS (Contrôle en Ligne de l’hAdronthérapie par RaYonnements Secondaires) for on-line monitoring of hadron therapy. It relies on the imaging of nuclear reaction products that is related to the ion range. The goal here is to provide large area beam detectors with a high detection efficiency for carbon or proton beams giving time and position measurement at 100 MHz count rates (beam tagging hodoscope). High radiation hardness and intrinsic electronic properties make diamonds reliable and very fast detectors with a good signal to noise ratio. Commercial Chemical Vapor Deposited (CVD) poly-crystalline, heteroepitaxial and monocrystalline diamonds were studied. Their applicability as a particle detector was investigated using α and β radioactive sources, 95 MeV/u carbon ion beams at GANIL and 8.5 keV X-ray photon bunches from ESRF. This facility offers the unique capability of providing a focused (~1 μm) beam in bunches of 100 ps duration, with an almost uniform energy deposition in the irradiated detector volume, therefore mimicking the interaction of single ions. A signal rise time resolution ranging from 20 to 90 ps rms and an energy resolution of 7 to 9% were measured using diamonds with aluminum disk shaped surface metallization. This enabled us to conclude that polycrystalline CVD diamond detectors are good candidates for our beam tagging hodoscope development. Recently, double-side stripped metallized diamonds were tested using the XBIC (X Rays Beam Induced Current) set-up of the ID21 beamline at ESRF which permits us to evaluate the capability of diamond to be used as position sensitive detector. The final detector will consist in a mosaic arrangement of double-side stripped diamond sensors read out by a dedicated fast-integrated electronics of several hundreds of channels.

Applications of a novel detector for pencil beam scanning proton therapy beam quality assurance

2021 ◽  
pp. 2140041
Author(s):  
Pei-Ying Yang ◽  
Yang-Wei Hsieh ◽  
Chen-Lin Kang ◽  
Chin-Dar Tseng ◽  
Chih-Hsueh Lin ◽  
...  
Keyword(s):  
Quality Assurance ◽  
Proton Therapy ◽  
Beam Quality ◽  
Beam Width ◽  
Scanning Speed ◽  
Spot Size ◽  
Pencil Beam ◽  
Beam Position ◽  
The Cross ◽  
One Year

This study utilized a new type of detector, the CROSS II (Liverage Biomedical Inc., Taiwan), to perform a beam quality assurance (QA) procedure on a Sumitomo (Sumitomo Heavy Industries, Inc., Japan) pencil beam linear scanning proton therapy machine. The Cross II can monitor proton Pristine Bragg peak range, beam width, beam size, beam position, and scanning speed. All the data presented here were collected during a time span of over one year. The accuracy of the QA program could be verified if all the QA items were tested stably and within the programmed tolerances. Our results showed that the proton range remained within the [Formula: see text] mm tolerance, with the majority of measurements within [Formula: see text] mm, [Formula: see text] mm for spot size, 1.5 mm for spot position, and [Formula: see text]% for scanning speed. We found that the CROSS II detector is in high precise and steady state with highly efficient. Our proton therapy system was also proven to be in an accurate and reliable condition according to our QA results.

Chemical-vapor-deposition growth and characterization of epitaxial 3C–SiC films on SOI substrates with thin silicon top layers

2001 ◽  
Vol 16 (1) ◽  
pp. 24-27 ◽  
Author(s):  
C. K. Moon ◽  
H. J. Song ◽  
J. K. Kim ◽  
J. H. Park ◽  
S. J. Jang ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Silicon On Insulator ◽  
Significant Shift ◽  
Misfit Dislocations ◽  
Chemical Vapor Deposition Growth ◽  
Hydrogen Flow ◽  
Soi Substrates ◽  
Sic Films

Epitaxial 3C–SiC films were grown by chemical vapor deposition on the silicon-on-insulator (SOI) substrates with 20–75-nm-thick Si top layers. A relatively low growth temperature of 1150 °C and a reduced hydrogen flow rate of 1 lpm during the precarbonization process was necessary to preserve the SOI structure and thereby obtain high-quality SiC films. The transmission electron microscopy observation of the SiC/SOI structures revealed high density of misfit dislocations in the SiC film, but no dislocation within the top Si layer. The x-ray-diffraction results did not show any significant shift of the (400) SiC peak position among the SiC/Si and the SiC/SOI samples. This strongly suggests that the Si top layer is not deformed during the SiC/SOI growth and the strain within the 3C–SiC layer is not critically affected by substituting the Si substrate with the SOI substrate, even when the Si top layer is as thin as 20 nm.

scholarly journals Monoenergetic proton beam accelerated by single reflection mechanism only during hole-boring stage

2019 ◽  
Vol 7 ◽  
Author(s):  
Wenpeng Wang ◽  
Cheng Jiang ◽  
Shasha Li ◽  
Hao Dong ◽  
Baifei Shen ◽  
...  
Keyword(s):  
Proton Beam ◽  
Radiation Pressure ◽  
Proton Therapy ◽  
Beam Quality ◽  
Acceleration Process ◽  
Carbon Ions ◽  
Triple Layer ◽  
Rear Part ◽  
Beam Instabilities ◽  
Sharp Front

Multidimensional instabilities always develop with time during the process of radiation pressure acceleration, and are detrimental to the generation of monoenergetic proton beams. In this paper, a sharp-front laser is proposed to irradiate a triple-layer target (the proton layer is set between two carbon ion layers) and studied in theory and simulations. It is found that the thin proton layer can be accelerated once to hundreds of MeV with monoenergetic spectra only during the hole-boring (HB) stage. The carbon ions move behind the proton layer in the light-sail (LS) stage, which can shield any further interaction between the rear part of the laser and the proton layer. In this way, proton beam instabilities can be reduced to a certain extent during the entire acceleration process. It is hoped such a mechanism can provide a feasible way to improve the beam quality for proton therapy and other applications.

Large-scale and facile fabrication of PbSe nanostructures by selenization of a Pb sheet

2015 ◽  
Vol 08 (05) ◽  
pp. 1550063 ◽  
Author(s):  
Sara Hoomi ◽  
Ramin Yousefi ◽  
Farid Jamali-Sheini ◽  
Abdolhossein Sáaedi ◽  
Mohsen Cheraghizade ◽  
...  
Keyword(s):  
Large Scale ◽  
Chemical Vapor ◽  
Infrared Region ◽  
Photoelectron Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Facile Fabrication ◽  
Higher Temperature ◽  
Set Up ◽  
Lower Temperature

PbSe nanostructures were synthesized by selenization of lead sheets in a chemical vapor deposition (CVD) set-up under a selenium ambiance. The lead sheets were placed in the different temperature zones, between 300°C and 450°C. Field emission scanning electron microscope (FESEM) images showed that, PbSe nanostructures grown on the lead sheets with different morphologies. PbSe nanostructures with flakes shape were grown on the lead sheets that were placed in the lower temperature, while PbSe nanocubes and nanorods, which were grown on the nanocubes, were grown on the lead sheets in the higher temperature. The phase and composition of the product were identified by X-ray diffraction (XRD) pattern and X-ray photoelectron spectra (XPS). The XRD and XPS results showed that, the PbSe phase was started to form after 350°C and completed at 450°C. However, the XPS results showed that the Se concentration was different in the samples. In addition, Raman measurements confirmed the XRD and XPS results and indicated three Raman active modes, which belonged to PbSe phase for the nanostructures. The optical properties of the products were characterized by UV–Vis. The optical characterization results showed a band gap for the PbSe nanostructures in the infrared region.

scholarly journals PO-0907 Gafchromic EBT3 film for absolute dosimetry in proton therapy based on averaging of beam quality

2019 ◽  
Vol 133 ◽  
pp. S482-S483 ◽  
Author(s):  
A. Resch ◽  
P. Heyes ◽  
H. Fuchs ◽  
D. Georg ◽  
P. Hugo
Keyword(s):  
Proton Therapy ◽  
Beam Quality

Use of a two-dimensional ionization chamber array for proton therapy beam quality assurance

2008 ◽  
Vol 35 (9) ◽  
pp. 3889-3894 ◽  
Author(s):  
Bijan Arjomandy ◽  
Narayan Sahoo ◽  
Xiaoning Ding ◽  
Michael Gillin
Keyword(s):  
Quality Assurance ◽  
Proton Therapy ◽  
Ionization Chamber ◽  
Beam Quality ◽  
Two Dimensional

Wafer level microarcing model in 90nm chemical-vapor deposition low-k via etch on 300mm silicon-on-insulator substrate

2006 ◽  
Vol 24 (4) ◽  
pp. 1404-1409 ◽  
Author(s):  
Hai Cong ◽  
Chun Hui Low ◽  
Yelehanka Ramachandramurthy Pradeep ◽  
Xin Zhang ◽  
Perera Chandima ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Silicon On Insulator ◽  
Wafer Level ◽  
Low K ◽  
Insulator Substrate
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