Systematic Patient-Dose Errors For 4- and 10-MeV Microwave Linear Accelerators Associated with Rectangular Collimator Settings

Radiology ◽  
1978 ◽  
Vol 129 (3) ◽  
pp. 803-806 ◽  
Author(s):  
Robert F. Moyer
Keyword(s):  
Patient Dose ◽  
Linear Accelerators ◽  
Dose Errors

scholarly journals Per-beam, planar IMRT QA passing rates do not predict clinically relevant patient dose errors

2011 ◽  
Vol 38 (2) ◽  
pp. 1037-1044 ◽  
Author(s):  
Benjamin E. Nelms ◽  
Heming Zhen ◽  
Wolfgang A. Tomé
Keyword(s):  
Patient Dose ◽  
Imrt Qa ◽  
Passing Rates ◽  
Dose Errors

SU-E-T-37: Evaluation of Software Systems That Estimate Patient Dose Errors Based on Planar IMRT QA Measurements

2012 ◽  
Vol 39 (6Part10) ◽  
pp. 3710-3711 ◽  
Author(s):  
M Bakhtiari ◽  
A Parniani ◽  
F Lerma ◽  
S Reynolds ◽  
J Jordan ◽  
...  
Keyword(s):  
Patient Dose ◽  
Software Systems ◽  
Imrt Qa ◽  
Dose Errors

scholarly journals Patient Dose Management: Focus on Practical Actions

2016 ◽  
Vol 31 (Suppl 1) ◽  
pp. S45 ◽  
Author(s):  
Michael Yong Park ◽  
Seung Eun Jung
Keyword(s):  
Patient Dose ◽  
Dose Management

USE OF CLINICAL EXPOSURE INDEX AND DEVIATION INDEX BASED ON NATIONAL DIAGNOSTIC REFERENCE LEVEL AS DOSE-OPTIMIZATION TOOLS FOR GENERAL RADIOGRAPHY IN KOREA

2020 ◽  
Vol 191 (4) ◽  
pp. 439-451
Author(s):  
Hyemin Park ◽  
Yongsu Yoon ◽  
Jungmin Kim ◽  
Jungsu Kim ◽  
Hoiwoun Jeong ◽  
...  
Keyword(s):  
Patient Dose ◽  
Reference Level ◽  
Dose Optimization ◽  
International Electrotechnical Commission ◽  
Exposure Index ◽  
Clinical Exposure ◽  
Deviation Index ◽  
Clinical Environments ◽  
Anterior Posterior ◽  
Exposure Conditions

Abstract The International Electrotechnical Commission introduced the concepts of exposure index (EI), target exposure index (EIT) and deviation index (DI) to manage and optimize patient dose in real time. In this study, we have proposed an appropriate method for setting the EIT based on the Korean national diagnostic reference levels (DRLs). Furthermore, we evaluated the use of clinical EI, EIT and DI as tools for patient dose optimization in clinical environments by observing the changes in DI with those in EIT. According to the Korean national exposure conditions, we conducted experiments on three representative radiographic examinations (chest posterior–anterior, lateral and abdomen anterior–posterior) of clinical environments. As the exposure conditions and DRLs varied, the clinical EI, EIT and DI also varied. These results reveal that the clinical EI, EIT and DI can be used as tools for optimizing the patient dose if EIT is periodically and properly updated.

scholarly journals Few-Cycle Infrared Pulse Evolving in FEL Oscillators and Its Application to High-Harmonic Generation for Attosecond Ultraviolet and X-ray Pulses

Atoms ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 15
Author(s):  
Ryoichi Hajima
Keyword(s):  
Harmonic Generation ◽  
Short Pulse ◽  
High Harmonic ◽  
High Harmonic Generation ◽  
Pulse Generation ◽  
Solid State Lasers ◽  
Linear Accelerators ◽  
X Ray ◽  
Ultrafast Science ◽  
Historical Remarks

Generation of few-cycle optical pulses in free-electron laser (FEL) oscillators has been experimentally demonstrated in FEL facilities based on normal-conducting and superconducting linear accelerators. Analytical and numerical studies have revealed that the few-cycle FEL lasing can be explained in the frame of superradiance, cooperative emission from self-bunched systems. In the present paper, we review historical remarks of superradiance FEL experiments in short-pulse FEL oscillators with emphasis on the few-cycle pulse generation and discuss the application of the few-cycle FEL pulses to the scheme of FEL-HHG, utilization of infrared FEL pulses to drive high-harmonic generation (HHG) from gas and solid targets. The FEL-HHG enables one to explore ultrafast science with attosecond ultraviolet and X-ray pulses with a MHz repetition rate, which is difficult with HHG driven by solid-state lasers. A research program has been launched to develop technologies for the FEL-HHG and to conduct a proof-of-concept experiment of FEL-HHG.

Patient dose from kilovoltage cone beam computed tomography imaging in radiation therapy

2006 ◽  
Vol 33 (6Part1) ◽  
pp. 1573-1582 ◽  
Author(s):  
Mohammad K. Islam ◽  
Thomas G. Purdie ◽  
Bernhard D. Norrlinger ◽  
Hamideh Alasti ◽  
Douglas J. Moseley ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Radiation Therapy ◽  
Cone Beam Computed Tomography ◽  
Patient Dose ◽  
Cone Beam ◽  
Computed Tomography Imaging ◽  
Tomography Imaging

scholarly journals Development and characterization of Nb3Sn/Al2O3 superconducting multilayers for particle accelerators

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chris Sundahl ◽  
Junki Makita ◽  
Paul B. Welander ◽  
Yi-Feng Su ◽  
Fumitake Kametani ◽  
...  
Keyword(s):  
High Performance ◽  
High Energy ◽  
Particle Accelerators ◽  
Quality Factors ◽  
Critical Fields ◽  
Linear Accelerators ◽  
Cross Sectional ◽  
Low Field ◽  
Superconducting Radio Frequency

AbstractSuperconducting radio-frequency (SRF) resonator cavities provide extremely high quality factors > 1010 at 1–2 GHz and 2 K in large linear accelerators of high-energy particles. The maximum accelerating field of SRF cavities is limited by penetration of vortices into the superconductor. Present state-of-the-art Nb cavities can withstand up to 50 MV/m accelerating gradients and magnetic fields of 200–240 mT which destroy the low-dissipative Meissner state. Achieving higher accelerating gradients requires superconductors with higher thermodynamic critical fields, of which Nb3Sn has emerged as a leading material for the next generation accelerators. To overcome the problem of low vortex penetration field in Nb3Sn, it has been proposed to coat Nb cavities with thin film Nb3Sn multilayers with dielectric interlayers. Here, we report the growth and multi-technique characterization of stoichiometric Nb3Sn/Al2O3 multilayers with good superconducting and RF properties. We developed an adsorption-controlled growth process by co-sputtering Nb and Sn at high temperatures with a high overpressure of Sn. The cross-sectional scanning electron transmission microscope images show no interdiffusion between Al2O3 and Nb3Sn. Low-field RF measurements suggest that our multilayers have quality factor comparable with cavity-grade Nb at 4.2 K. These results provide a materials platform for the development and optimization of high-performance SIS multilayers which could overcome the intrinsic limits of the Nb cavity technology.

scholarly journals Synchrotron X-ray induced acoustic imaging

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Seongwook Choi ◽  
Eun-Yeong Park ◽  
Sinyoung Park ◽  
Jong Hyun Kim ◽  
Chulhong Kim
Keyword(s):  
Acoustic Imaging ◽  
Signal Frequency ◽  
X Rays ◽  
Repetition Period ◽  
Linear Accelerators ◽  
X Ray ◽  
X Ray Computed ◽  
Medical Linear Accelerators ◽  
Ionizing Radiation Exposure ◽  
X Ray Absorption

AbstractX-ray induced acoustic imaging (XAI) is an emerging biomedical imaging technique that can visualize X-ray absorption contrast at ultrasound resolution with less ionizing radiation exposure than conventional X-ray computed tomography. So far, medical linear accelerators or industrial portable X-ray tubes have been explored as X-ray excitation sources for XAI. Here, we demonstrate the first feasible synchrotron XAI (sXAI). The synchrotron generates X-rays, with a dominant energy of 4 to 30 keV, a pulse-width of 30 ps, a pulse-repetition period of 2 ns, and a bunch-repetition period of 940 ns. The X-ray induced acoustic (XA) signals are processed in the Fourier domain by matching the signal frequency with the bunch-repetition frequency. We successfully obtained two-dimensional XA images of various lead targets. This novel sXAI tool could complement conventional synchrotron applications.

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