IBIC2019 - List of Authors (Hwang, J.G.)

Paper	Title	Page
MOCO04	Overview of Bunch-Resolved Diagnostics for the Future BESSY VSR Electron-Storage Ring	50
	G. Schiwietz, J.G. Hwang, M. Koopmans, M. Ries HZB, Berlin, Germany
	The upgrade of the BESSY II light source in Berlin towards the Variable pulse-length Storage-Ring BESSY VSR will lead to a complex fill pattern. This involves co-existing electron bunches with significant variations of bunch-length, bunch charge as well as charge density. Among many other boundary conditions, this calls for bunch resolved measurements with sub-ps time resolution and micrometer spatial resolution. Currently, we are constructing a diagnostic platform connected to three new dipole beamlines for visible light as well as THz measurements. The mid-term aim is a 24/7 use of beam-diagnostic tools and the development of advanced methods for specific purposes. Recently, we have set-up a sub-ps streak camera* and we are investigating other innovative methods for bunch-length as well as lateral size determination using visible light* at the first of our new diagnostic dipole beamlines. Preliminary results as well as our concepts for achieving high sensitivity, good signal-to-noise ratio and time resolution will be presented and discussed at the conference. * G.Schiwietz et al., J.Phys.:Conf. Series 1067, 072005 (2018) T.Mitsuhashi, M.Tadano, Proc. of EPAC¿02, Paris, France, p. 1936 * J.Breunlin et al., NIM- A803, pp.55 (2015) &refs. therein
	Slides MOCO04 [10.924 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-MOCO04
About •	paper received ※ 04 September 2019 paper accepted ※ 08 September 2019 issue date ※ 10 November 2019
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TUPP027	Development of a Precision Pepper-Pot Emittance Meter	369
	G. Hahn PAL, Pohang, Republic of Korea J.G. Hwang HZB, Berlin, Germany
	A fast single-shot emittance measurement device, a pepper-pot emittance meter, was developed. In the manufacturing stage, in order to guarantee the quality of the holes in the pepper-pot mask, we fabricated two mask using different methods that are made of phosphor bronze by optical lithography process and SUS by laser cutting. After the comparison of each SEM (Scanning Electron Microscope) measurement data, the phosphor bronze mask fabricated by lithography was found to be suitable. The rotation and translation matrices are applied on all images obtained by the camera to mitigate the relative angular misalignment errors between MCP, mirror and CMOS camera with respect to the mask. By applying the instrument in the NFRI ion source, the four-dimensional phase-space distribution of ion beams is retrieved and compared with the result measured by using a slit-scan method. In this paper, we describe the fabrication process, data analysis method and beam measurement results of the developed emittance meter.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-TUPP027
About •	paper received ※ 09 September 2019 paper accepted ※ 10 September 2019 issue date ※ 10 November 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPP003	A new button-type beam position monitor for BESSY II and BESSY VSR	508
	J.G. Hwang, V. Dürr, F. Falkenstern, M. Ries, A. Schälicke, G. Schiwietz, D. Wolk HZB, Berlin, Germany
	Funding: This work was supported by the German Bundesministerium für Bildung und Forschung, Land Berlin and grants of Helmholtz Association. The future BESSY VSR system involves more than one order-of-magnitude differences in the total charge of adjacent short and long bunches within the bunch train. Thus, any signal ringing beyond a nanosecond in time will cause a misreading of beam position and current, specifically for low bunch charges. This calls for improved performance for the bunch-selective operation of the beam-position-monitor (BPM) system. We report on the corresponding design and fabrication of a new button BPM with advanced features, such as impedance matching inside the button as well as optimization of insulator material, button size, and position, for reduced crosstalk between buttons.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-WEPP003
About •	paper received ※ 04 September 2019 paper accepted ※ 10 September 2019 issue date ※ 10 November 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Overview of Bunch-Resolved Diagnostics for the Future BESSY VSR Electron-Storage Ring

50

G. Schiwietz, J.G. Hwang, M. Koopmans, M. Ries
HZB, Berlin, Germany

The upgrade of the BESSY II light source in Berlin towards the Variable pulse-length Storage-Ring BESSY VSR will lead to a complex fill pattern. This involves co-existing electron bunches with significant variations of bunch-length, bunch charge as well as charge density. Among many other boundary conditions, this calls for bunch resolved measurements with sub-ps time resolution and micrometer spatial resolution. Currently, we are constructing a diagnostic platform connected to three new dipole beamlines for visible light as well as THz measurements. The mid-term aim is a 24/7 use of beam-diagnostic tools and the development of advanced methods for specific purposes. Recently, we have set-up a sub-ps streak camera* and we are investigating other innovative methods for bunch-length** as well as lateral size determination using visible light*** at the first of our new diagnostic dipole beamlines. Preliminary results as well as our concepts for achieving high sensitivity, good signal-to-noise ratio and time resolution will be presented and discussed at the conference.
* G.Schiwietz et al., J.Phys.:Conf. Series 1067, 072005 (2018)
** T.Mitsuhashi, M.Tadano, Proc. of EPAC¿02, Paris, France, p. 1936
*** J.Breunlin et al., NIM- A803, pp.55 (2015) &refs. therein

Slides MOCO04 [10.924 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-MOCO04

About •

paper received ※ 04 September 2019 paper accepted ※ 08 September 2019 issue date ※ 10 November 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPP027

Development of a Precision Pepper-Pot Emittance Meter

369

G. Hahn
PAL, Pohang, Republic of Korea
J.G. Hwang
HZB, Berlin, Germany

A fast single-shot emittance measurement device, a pepper-pot emittance meter, was developed. In the manufacturing stage, in order to guarantee the quality of the holes in the pepper-pot mask, we fabricated two mask using different methods that are made of phosphor bronze by optical lithography process and SUS by laser cutting. After the comparison of each SEM (Scanning Electron Microscope) measurement data, the phosphor bronze mask fabricated by lithography was found to be suitable. The rotation and translation matrices are applied on all images obtained by the camera to mitigate the relative angular misalignment errors between MCP, mirror and CMOS camera with respect to the mask. By applying the instrument in the NFRI ion source, the four-dimensional phase-space distribution of ion beams is retrieved and compared with the result measured by using a slit-scan method. In this paper, we describe the fabrication process, data analysis method and beam measurement results of the developed emittance meter.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-TUPP027

About •

paper received ※ 09 September 2019 paper accepted ※ 10 September 2019 issue date ※ 10 November 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPP003

A new button-type beam position monitor for BESSY II and BESSY VSR

508

J.G. Hwang, V. Dürr, F. Falkenstern, M. Ries, A. Schälicke, G. Schiwietz, D. Wolk
HZB, Berlin, Germany

Funding: This work was supported by the German Bundesministerium für Bildung und Forschung, Land Berlin and grants of Helmholtz Association.
The future BESSY VSR system involves more than one order-of-magnitude differences in the total charge of adjacent short and long bunches within the bunch train. Thus, any signal ringing beyond a nanosecond in time will cause a misreading of beam position and current, specifically for low bunch charges. This calls for improved performance for the bunch-selective operation of the beam-position-monitor (BPM) system. We report on the corresponding design and fabrication of a new button BPM with advanced features, such as impedance matching inside the button as well as optimization of insulator material, button size, and position, for reduced crosstalk between buttons.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-WEPP003

About •

paper received ※ 04 September 2019 paper accepted ※ 10 September 2019 issue date ※ 10 November 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)