IPAC2022 - List of Authors (Cha, H.J.)

Paper	Title	Page
WEPOST034	Magnetic Characterization of a Superconducting Transverse Gradient Undulator for Compact Laser Wakefield Accelerator-Driven FELs	1772
SUSPMF035	use link to see paper's listing under its alternate paper code
	K. Damminsek, A. Bernhard, H.J. Cha, A.W. Grau, A.-S. Müller, M.S. Ning, Y. Tong KIT, Karlsruhe, Germany S.C. Richter CERN, Meyrin, Switzerland R. Rossmanith DESY, Hamburg, Germany
	Funding: Federal Ministry of Education and Research of Germany and the Development and Promotion of Science and Technology Talents Project (DPST) A transverse gradient undulator (TGU) is a key component compensating for the relatively large energy spread of Laser Wakefield Accelerator (LWFA)-generated electron beams for realizing a compact Free Electron Laser (FEL). A superconducting TGU with 40 periods has been fabricated at the Karlsruhe Institute of Technology (KIT). In this contribution, we report that the superconducting TGU has been commissioned with nominal operational parameters at an off-line test bench. An experimental set-up for mapping the magnetic field on a two-dimensional grid in the TGU gap has been employed for the magnetic characterization. We show the first preliminary results of these measurements showing the longitudinal quality, the transverse gradient and the transient behaviour of the superconducting TGU field.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOST034
About •	Received ※ 08 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 20 June 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPOST027	Fabrication of Robust Thermal Transition Modules and First Cryogenic Experiment with the Refurbished COLDDIAG	2505
	H.J. Cha, N. Glamann, A.W. Grau, A.-S. Müller, D. Saez de Jauregui KIT, Eggenstein-Leopoldshafen, Germany
	Funding: This work is supported by the BMBF project 05H18VKRB1 HIRING (Federal Ministry of Education and Research). Two sets of thermal transition modules as a key component for the COLDDIAG (cold vacuum chamber for beam heat load diagnostics) refurbishment were manufactured, based on the previous design study. The modules are installed in the existing COLDDIAG cryostat and tested with an operating temperature of approximately 50 K at both a cold bore and a thermal shield. This cool-down experiment is a preliminary investigation aiming at beam heat-load studies at the FCC-hh where the beam screens will be operated at almost the same temperature. In this contribution, we report the fabrication processes of the mechanically robust transition modules and the first thermal measurement results with the refurbished COLDDIAG in a cryogenic environment. The static heat load in the refurbished cryostat remains unchanged, compared to that in the former one (4-K cold bore and 50-K shield with thin transitions), despite the increase in the transition thickness. It originates from the identical temperature at the cold bore and the shield, which can theoretically allow the heat intakes by thermal conduction and radiation between them to vanish.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOST027
About •	Received ※ 16 May 2022 — Accepted ※ 13 June 2022 — Issue date ※ 10 July 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Magnetic Characterization of a Superconducting Transverse Gradient Undulator for Compact Laser Wakefield Accelerator-Driven FELs

1772

SUSPMF035

use link to see paper's listing under its alternate paper code

K. Damminsek, A. Bernhard, H.J. Cha, A.W. Grau, A.-S. Müller, M.S. Ning, Y. Tong
KIT, Karlsruhe, Germany
S.C. Richter
CERN, Meyrin, Switzerland
R. Rossmanith
DESY, Hamburg, Germany

Funding: Federal Ministry of Education and Research of Germany and the Development and Promotion of Science and Technology Talents Project (DPST)
A transverse gradient undulator (TGU) is a key component compensating for the relatively large energy spread of Laser Wakefield Accelerator (LWFA)-generated electron beams for realizing a compact Free Electron Laser (FEL). A superconducting TGU with 40 periods has been fabricated at the Karlsruhe Institute of Technology (KIT). In this contribution, we report that the superconducting TGU has been commissioned with nominal operational parameters at an off-line test bench. An experimental set-up for mapping the magnetic field on a two-dimensional grid in the TGU gap has been employed for the magnetic characterization. We show the first preliminary results of these measurements showing the longitudinal quality, the transverse gradient and the transient behaviour of the superconducting TGU field.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOST034

About •

Received ※ 08 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 20 June 2022

Cite •

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

THPOST027

Fabrication of Robust Thermal Transition Modules and First Cryogenic Experiment with the Refurbished COLDDIAG

2505

H.J. Cha, N. Glamann, A.W. Grau, A.-S. Müller, D. Saez de Jauregui
KIT, Eggenstein-Leopoldshafen, Germany

Funding: This work is supported by the BMBF project 05H18VKRB1 HIRING (Federal Ministry of Education and Research).
Two sets of thermal transition modules as a key component for the COLDDIAG (cold vacuum chamber for beam heat load diagnostics) refurbishment were manufactured, based on the previous design study. The modules are installed in the existing COLDDIAG cryostat and tested with an operating temperature of approximately 50 K at both a cold bore and a thermal shield. This cool-down experiment is a preliminary investigation aiming at beam heat-load studies at the FCC-hh where the beam screens will be operated at almost the same temperature. In this contribution, we report the fabrication processes of the mechanically robust transition modules and the first thermal measurement results with the refurbished COLDDIAG in a cryogenic environment. The static heat load in the refurbished cryostat remains unchanged, compared to that in the former one (4-K cold bore and 50-K shield with thin transitions), despite the increase in the transition thickness. It originates from the identical temperature at the cold bore and the shield, which can theoretically allow the heat intakes by thermal conduction and radiation between them to vanish.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOST027

About •

Received ※ 16 May 2022 — Accepted ※ 13 June 2022 — Issue date ※ 10 July 2022

Cite •

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