Zobrazeno 1 - 10
of 50
pro vyhledávání: '"Chongdo Park"'
Publikováno v:
AIP Advances, Vol 12, Iss 3, Pp 035025-035025-9 (2022)
We present a numerical method of calculating the pressure profile of a large ultra-high vacuum (UHV) system using finite-element analysis (FEA) that exploits the continuity of gas flow. In this study, we introduce a modified FEA (MFEA) that excludes
Externí odkaz:
https://doaj.org/article/e16cce96b30443b596ae22411d24a73f
Publikováno v:
Journal of Vacuum Science & Technology B. 41:014202
The concept of transmission conductance is required to describe phenomena occurring in a tube with wall pumping. This is because the gas flow is not constant along the length of the tube but decreases, which implies that the geometric conductance det
Autor:
Seunghwan Shin, Jae-Young Choi, Ilmoon Hwang, Sung Chul Kim, Changbum Kim, Chongdo Park, Mungyung Kim
Publikováno v:
Journal of the Korean Physical Society. 71:775-779
The upgraded Pohang-Light-Source (PLS-II) was opened to the public in 2012. Among many improvements of the PLS-II, a top-up operation was one of the highlights of them, and the stability of the electron beam was improved significantly. For the top-up
Publikováno v:
Applied Science and Convergence Technology. 25:67-72
This article describes an electrical network analysis (ENA) method to calculate the pressure distribution of a vacuum system in a molecular flow regime. The vacuum system was modeled using electrical components. For an accurate analysis, a complexly
Publikováno v:
Applied Science and Convergence Technology. 24:84-89
The base pressure and outgassing rate of a mild steel chamber were measured and compared to those of a stainless steel chamber. A combined sputter-ion and non-evaporable getter pump with a nominal pumping speed of 490 l/s generated the base pressure
Publikováno v:
Journal of Visualized Experiments.
Steels are commonly used materials in the fabrication of vacuum systems because of their good mechanical, corrosion, and vacuum properties. A variety of steels meet the criterion of low outgassing required for high or ultrahigh vacuum applications. H
In the storage ring of PLS-II, we reduced mechanical displacement of electron beam position monitors (e-BPMs) that is caused by heating during e-beam storage. The orbit feedback system intends that the electron beam pass through the center of the BPM
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::e0688f4a6d9f06315bbb75e02157904c
Publikováno v:
Journal of the Korean Vacuum Society. 20:1-6
A sudden step change is observed in the vertical position readings from beam position monitors (BPMs) mounted at the several sector vacuum chambers of Pohang Light Source. To study the source of this sudden step change, we measured the RF transmissio
Autor:
Chongdo Park, Changbum Kim, Jung Yun Huang, Hae Cheol Lee, Hee Seob Kim, Man-soo Hong, In Soo Ko, Jong Chel Yoon, Chun Kil Ryu, Yeongjin Han, Myong-jin Kim, Seung-Nam Kim, Chae-Soon Lee, Jaehun Park, In Deuk Seo
Publikováno v:
Journal of the Korean Physical Society. 56:1981-1984
Publikováno v:
Europhysics Letters (EPL). 74:903-908
We propose that dynamically induced internal fields be utilized in obtaining materials with low dielectric constant at high frequencies. We also demonstrate the validity of the proposal by measuring the effective dielectric constant of polyimide disp