Photon-beam-position-monitor in PLS Diagnostic Beamline

Kim, Changbum; Yoon, Jong Hwan; Kim, Seungnam; Kim, Myong-jin; Kim, Hee Seob; Ryu, C. M.; Lee, Chae-soon; Seo, In Deuk; Park, Chongdo; Lee, Hae Cheol; Hong, Man-soo; Huang, J. Y.; Han, Yeongjin; Park, Jaehun; Ko, In Soo

doi:10.3938/jkps.56.1981

Cited by 4 publications

(3 citation statements)

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“…An integrated transport code, which consists of a 1.5dimensional core transport code and a pellet injection module [7][8][9], is adopted to simulate the plasma transport and pellet injection in tokamak plasmas. The core transport code self-consistently calculates the continuity equation of electron density, the momentum equations of electron and ion, the current diffusion equation and the toroidal momentum equation.…”

Section: Numerical Models Of Pellet Injection and Plasma Transportmentioning

confidence: 99%

“…The H-mode transition from L-mode is assumed to occur when the power across the separatrix exceeds the H-mode threshold power scaled by the ITER database [19]. After the H-mode transition, the turbulence suppression functions composed of magnetic and rotational shears [8,20] are switched on so that an H-mode pedestal may build up until reaching the pressure gradient limited by ELM.…”

Section: Numerical Models Of Pellet Injection and Plasma Transportmentioning

confidence: 99%

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Transport simulation of ELM pacing by pellet injection in tokamak plasmas

Kim¹,

Na²,

Hong³

et al. 2010

Nucl. Fusion

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This paper deals mainly with the numerical simulation on edge localized mode (ELM) pacing by pellet injection that is useful for fuelling and control of plasma profiles to achieve enhanced tokamak operations. The fuelling and pellet-induced ELMs are simulated with a 1.5-dimensional core transport code, which includes a neutral gas shielding model and a grad-B drift model for pellet deposition in H-mode tokamak plasmas. Fuelling and ELM pacing experiments by pellet injections at JET are introduced as a current experimental approach. For the description of ELM triggering by pellet injection based on ideal ballooning mode criteria, three possible models are suggested and discussed on their ELM characteristics, respectively: (i) the density enhanced ELMs in the post-pellet phase, (ii) the modification of the surface averaged pressure profiles in a transport time scale and (iii) the local increase in the pressure (density and/or temperature) gradients perturbed by pellets. Among them, the pellet-induced density perturbation model is adopted, in practice, to carry out an ELM pacing simulation in preparation for future experiments in KSTAR. The numerical simulation shows that the artificially induced ELM by pellets releases the reduced energy bursts, compared with spontaneous ELMs. The energy loss per burst by the pellet-induced ELM turns out to be much smaller than that by the spontaneous ELM as the pellet injection frequency becomes higher in ELM pacing. Based on the simulation results showing good agreement with the general ELM characteristics observed in pellet pacing experiments, the ELM pacing by pellet injection is very promising for mitigating the ELM energy bursts to the divertor by controlling the injection frequency.

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Section: Numerical Models Of Pellet Injection and Plasma Transportmentioning

confidence: 99%

Section: Numerical Models Of Pellet Injection and Plasma Transportmentioning

confidence: 99%

Transport simulation of ELM pacing by pellet injection in tokamak plasmas

Kim¹,

Na²,

Hong³

et al. 2010

Nucl. Fusion

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show abstract

“…PLS-II photon beam position monitor system [4] consists of pick-up, translation stage and Libera photon electronics. Figure 1 shows the pick-up for the PLS-II PBPM.…”

Section: Pls-ii Photon Beam Position Monitormentioning

confidence: 99%

Data analysis of photon beam position at PLS-II

Shin

Huang

et al. 2016

AIP Conference Proceedings

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Analysis and control of the photon beam position at PLS-II

Kim

et al. 2016

J Synchrotron Radiat

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At third-generation light sources, the photon beam position stability is a critical issue for user experiments. In general, photon beam position monitors are developed to detect the real photon beam position, and the position is controlled by a feedback system in order to maintain the reference photon beam position. At Pohang Light Source II, a photon beam position stability of less than 1 mm r.m.s. was achieved for a user service period in the beamline, where the photon beam position monitor is installed. Nevertheless, a detailed analysis of the photon beam position data was necessary in order to ensure the performance of the photon beam position monitor, since it can suffer from various unknown types of noise, such as background contamination due to upstream or downstream dipole radiation, and undulator gap dependence. This paper reports the results of a start-to-end study of the photon beam position stability and a singular value decomposition analysis to confirm the reliability of the photon beam position data.

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Photon-beam-position-monitor in PLS Diagnostic Beamline

Cited by 4 publications

References 0 publications

Transport simulation of ELM pacing by pellet injection in tokamak plasmas

Transport simulation of ELM pacing by pellet injection in tokamak plasmas

Data analysis of photon beam position at PLS-II

Analysis and control of the photon beam position at PLS-II

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