• Progress in Medical Physics
• /
• v.28 no.3
• /
• pp.129-133
• /
• 2017

The machine log files recorded by a scanning control unit in proton beam therapy system have been studied to be used as a quality assurance method of scanning beam deliveries. The accuracy of the data in the log files have been evaluated with a standard calibration beam scan pattern. The proton beam scan pattern has been delivered on a gafchromic film located at the isocenter plane of the proton beam treatment nozzle and found to agree within ${\pm}1.0mm$. The machine data accumulated for the scanning beam proton therapy of five different cases have been analyzed using a statistical method to estimate any systematic error in the data. The high-precision scanning beam log files in line scanning proton therapy system have been validated to be used for off-line scanning beam monitoring and thus as a patient-specific quality assurance method. The use of the machine log files for patient-specific quality assurance would simplify the quality assurance procedure with accurate scanning beam data.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.10a
• /
• pp.154-157
• /
• 2005

The use of electron-beam(E-Beam) manufacture systems provides a means to alleviate optic exposure equipment's problems. We designed an E-beam manufacture system with SEM function. Optimal beam scanning is one of the most important conditions in the performance of E-beam and SEM. The performance of E-beam manufacture system and images of SEM are a close affinity with each other. Developed E-beam manufacture system consist of the controllers of high voltage, scanning, optic and high voltage generator. In this paper, we analyze the condition of steady beam scanning and describe the development of controller fer optimal beam scanning.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.17 no.5
• /
• pp.1202-1207
• /
• 1993

An optical method of slit beam scanning topography is presented for the 3-dimensional profile measurement of free-formed surfaces. A slit beam of laser is projected in a scanning mode and its illuminated trajectory on the object is captured by using a CCD camera. The 3-dimensional coordinates of the trajectory is then computed by using the given geometry between the slit beam and the camera, so that the whole surface profile of the object can be obtained in a successive manner. Detailed optical principles are described with special emphasis to lateral are discussed to demonstrate the measuring performances of the slit beam scanning topography proposed in this study.

• Journal of the Semiconductor & Display Technology
• /
• v.18 no.3
• /
• pp.72-76
• /
• 2019

A Q-switched diode-pumped neodymium-doped yttrium vanadate (YVO₄, λ =1064nm) laser was used for the direct patterning of indium tin oxide (ITO) films on glass substrate. During the laser direct patterning, the laser beam was incident on the two different directions of glass substrate and the laser ablated patterns were compared and analyzed. At a low scanning speed of laser beam, the larger laser etched lines were obtained by laser beam incident in reverse side of glass substrate. On the contrary, at a higher scanning speed, the larger etched pattern sizes were found in case of the beam incidence from front side of glass substrate. Furthermore, it was impossible to find no ablated patterns in some laser beam conditions for the laser beam from reverse side at a much higher scanning speed and repetition rate of laser beam. The laser beam is expected to be transferred and scattered through the glass substrate and the laser beam energy is thought to be also dispersed and much more influenced by the overlapping of each laser beam spot.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.06a
• /
• pp.1875-1878
• /
• 2005

It is not efficient and scarcely out of the question to use commercial expensive electron beam lithography system widely used for semiconductor fabrication process for the manufacturing application field of various devices in the small business scope. Then scanning electron microscope based electron beam machining system is maybe regarded as a powerful model can be used for it simply. To get a complete suite of thus proper system, column unit build up with electron beam gun head unit is necessarily required more than anything else to modify scanning electron microscope. In this study, various components included ceramic isolation plate and main body which are essentially constructed for electron beam gun head unit are designed and manufactured. And this electron beam gun head unit will be used for next connected study in the development step of scanning electron microscope based electron beam machining system.

• Laser Solutions
• /
• v.18 no.3
• /
• pp.6-8
• /
• 2015

Finishing process includes deburring, polishing and edge radiusing. It improves the surface profile of specimen and eliminates the alien substance on surface. Deburring is the elimination process for debris of edges. Polishing lubricates surfaces by rubbing or chemical treatment. There are two types for electron finishing. The one is using pulse beam. The other is using the convergent and scanning electron beam. Pulse type device appropriates the large area process. But it does not control the beam dosage. Scanning type device has advantages for dosage control and edge deburring. We design the convergence and scan type. It has magnetic lenses for convergence and scan device for scanning beam. Magnetic lenses consist of convergent and objective lens. The lenses are designed by the specification(beam size and working distance). In this paper, we evaluate the convergence performance by pattern process. Also, we analysis the results and important factors for process. The important factors for process are beam size, pressure, stage speed and vacuum. These results will be utilized into systematizing pattern shape and the factors.

• Nuclear Engineering and Technology
• /
• v.54 no.11
• /
• pp.4310-4321
• /
• 2022

The concept of dense granular-flow target (DGT) for the China Initiative Accelerator Driven Subcritical system (CiADS) is an attractive choice for high heat removal ability, low chemical toxicity, and radiotoxicity. A wobbling hollow beam is proposed to enhance the homogeneity of temperature rise of flowing particles in beam-target coupling zone. In this paper, the design procedure of target and beam parameters was discussed firstly. Then we simulated the heat deposition and transfer of the scanning beam in DGT to study the effect of beam parameters. The results show the flux density of proton beam plays a crucial role in the distribution of temperature rise while the contributions from scanning frequency heat transfer are also obvious. Moreover, heat transfer in transversal directions is insignificant, resulting in a low heat flux towards the sidewalls of DGT. This work not only contributes to the design of DGT, but also beneficial for understanding the beam-target coupling in porous materials.

• Nuclear Engineering and Technology
• /
• v.54 no.3
• /
• pp.1016-1023
• /
• 2022

In proton therapy, a highly conformal proton dose can be delivered to the tumor by means of the steep distal dose penumbra at the end of the beam range. The proton beam range, however, is highly sensitive to range uncertainty, which makes accurately locating the proton range in the patient difficult. In-vivo range verification is a method to manage range uncertainty, one of the promising techniques being prompt gamma imaging (PGI). In earlier studies, we proposed gamma electron vertex imaging (GEVI), and constructed a proof-of-principle system. The system successfully demonstrated the GEVI imaging principle for therapeutic proton pencil beams without scanning, but showed some limitations under clinical conditions, particularly for pencil beam scanning proton therapy. In the present study, we upgraded the GEVI system in several aspects and tested the performance improvements such as for range-shift verification in the context of line scanning proton treatment. Specifically, the system showed better performance in obtaining accurate prompt gamma (PG) distributions in the clinical environment. Furthermore, high shift-detection sensitivity and accuracy were shown under various range-shift conditions using line scanning proton beams.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.22 no.8
• /
• pp.1622-1631
• /
• 1997

A 3-stages Active Microstrip Phased Array Antenn(AMPAA) is implemented using Injection-Locking Coupled Oscillators(ILCO). The AMPAA is a beam scanning active antenna with capability of electrical scanning by frequency varation of ILCO. The synchronization of resonance frequencies in array elements is occured by ILCO, and the ILCO amplifies the injection signal and functions as a phase shifter. The microstrip ptch is operated as a radiation element. The unilateral amplifier is a mutual coupling element of AMPAA, eliminates the reverse locking signal and controls the locking bandwidth of ILCO. The possibility of Monolithic Microwave Integrated Circuits(MMIC) of T/R module is proposed by simplified and integrated fabrication process of AMPAA. The 0.75.$lambda_{0}$ is fixed for a mutual coupling space to wide the scanning angle and minimize the multi-mode. The AMPAA has beam scanning angle of 31.4.deg., HPBW(Half Power Beam Widths) of 26.deg., directive gain of 13.64dB and side lobe of -16.5dB were measured, respectively.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.18 no.6
• /
• pp.558-564
• /
• 2009

To aim at obtaining a correct and fine small pattern by an electron beam lithography several conditions and methods affecting a real pattern shape needs to be investigated. A micro/nano sized pattern shape is sometimes dependent on the scanning method. In this work, four types of scanning methods are implemented and their characteristics are investigated. For a $11\times11um$ pattern, a Zigzag scanning method proves a precise pattern generation. The other ways such as SEM scanning and swirl in-out scanning method result in some distorted pattern shape. It is proved that abrupt change in the pattern generation limits to obtaining a fine and small pattern.