The first of a new generation of microtron accelerators has been installed and tested. It is currently in use for multisegment conformal radiotherapy at our institution. The unit produces x rays and electrons from 10 to 50 MeV in 5 MeV increments. It incorporates a 64 leaf, doubly focused multileaf collimator (MLC), which can be used to shape x-ray and electron beams. Both x-ray and electron beams are produced by magnetically scanning the electron beams from the accelerator. The new generation unit incorporates a purging magnet to sweep away any primary or secondary electrons that pass through the target(s). In this paper, the beam characteristics of the accelerator that were studied during acceptance testing are described. Representative examples of depth doses, beam profiles, output factors, and elementary beam distributions are presented and discussed, in comparison with the earlier generation of microtron accelerators and with other radiotherapy machines.

Download full-text PDF

Source
http://dx.doi.org/10.1118/1.597587DOI Listing

Publication Analysis

Top Keywords

electron beams
12
beam characteristics
8
generation microtron
8
microtron accelerators
8
x-ray electron
8
beam
4
generation
4
characteristics generation
4
generation mev
4
mev racetrack
4

Similar Publications

(1) Background: Ultra-high dose rate (UHDR) radiation therapy needs a reliable dosimetry solution and scintillation detectors are promising candidates. In this study, we characterized an inorganic powder-based scintillation detector under a 9 MeV UHDR electron beam. (2) Methods: A mixture of ZnS:Ag powder and optic glue was coupled to an 8 m Eska GH-4001-P polymethyl methacrylate (PMMA) optical fiber.

View Article and Find Full Text PDF

Effect of High-Energy Electron Beam Irradiation on the Structure and Thermoelectric Properties of Polypyrrole.

Polymers (Basel)

December 2024

Key Laboratory of Radiation Physics and Technology, Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University, Chengdu 610064, China.

The effects of different doses (10-100 kGy) of electron beams on the molecular structure, microstructure, and thermoelectric properties of polypyrrole (PPy) under high-energy electron beam irradiation (10 MeV) were studied. The results showed that after electron beam irradiation, the conductivity of PPy increased slightly, but the Seebeck coefficient and power factor remained relatively stable. The structural analysis of FTIR, Raman spectroscopy, and X-ray diffraction indicated that the molecular structure of PPy was strongly stable, and its microstructure was only slightly affected by electron beam irradiation.

View Article and Find Full Text PDF

Ultrasensitive platform for the determination of biothiols using aggregation-induced emission of gold-cysteine nanosheets.

Biosens Bioelectron

January 2025

Guangdong Laboratory of Artificial Intelligence and Digital Economy (SZ), Shenzhen University, Shenzhen, 518060, China; Marshall Laboratory of Biomedical Engineering, Shenzhen Key Laboratory of Nano-Biosensing Technology, School of Biomedical Engineering, Shenzhen University Medical School, Shenzhen University, Shenzhen, 518060, China. Electronic address:

Highly ordered ultrathin nanosheets (NSs) of Au(I)-Cys were fabricated through aggregation-induced supramolecular self-assembly triggered by an extended agitation in an alkaline environment. The synthesized Au(I)-Cys NSs exhibited intense luminescence and exceptional chirality. Remarkably, additions of biothiols to Au(I)-Cys NSs have significantly enhanced their luminescence emission, and circular dichroism properties coupled with morphological modulations into nanoflowers, nanodendrites, or closely packed aggregates.

View Article and Find Full Text PDF

Purpose: To perform vertical bone augmentation on rat parietal bone by coating the inner surface of dense polytetrafluoroethylene (d-PTFE) domes with hydroxyapatite (HA) using Erbium Yttrium Aluminum Garnet (Er:YAG) pulsed laser deposition in a rat model.

Methods: The d-PTFE plate surface, α-tricalcium phosphate (α-TCP) coating, and HA coating were measured using scanning electron microscopy and X-ray diffraction to confirm the replacement of α-TCP with HA via high-pressure steam sterilization. The dome was glued to the center of the rat parietal bone and closed with periosteal and epithelial sutures.

View Article and Find Full Text PDF

Trabecular meshwork ultrastructural changes in primary and secondary glaucoma.

Sci Rep

January 2025

Ophthalmic Pathology Laboratory, L V Prasad Eye Institute, Kallam Anji Reddy Campus, 500034, Hyderabad, India.

To examine ultrastructural changes in the trabecular meshwork (TM) in patients with primary and secondary glaucoma using scanning electron microscopy (SEM). This was a qualitative descriptive hospital-based study on the ultrastructure of the TM. Pure TM samples were collected after microincisional trabeculectomy from 26 patients with primary or secondary glaucoma and 10 control samples from eye bank donor corneas.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!