FLS2023 - List of Keywords (insertion-device)

Paper	Title	Other Keywords	Page
WE4P36	The Cryogenic Undulator Upgrade Programme at Diamond Light Source	vacuum, undulator, MMI, cryogenics	211
	Z. Patel, W. Cheng, A. George, S.H. Hale, R. Mercado, A. Ramezani Moghaddam, M. Reeves, G. Sharma, S. Tripathi DLS, Oxfordshire, United Kingdom M.V. Marziani University of Cape Town, Cape Town, South Africa
	Diamond Light Source has installed four 2 m long, 17.6 mm period Cryogenic Permanent Magnet Undulators (CPMUs) as upgrades for crystallography beamlines since 2020, with two more planned within the next year. The CPMUs provide 2 - 3 times more brightness and 2 - 4 times more flux than the pure permanent magnet (PPM) devices they are replacing. They have been designed, built, and measured in-house. All four have a 4 mm minimum operating gap and are almost identical in their construction: the main difference being an increase in the number of in-vacuum magnet beam support points from four to five, between CPMU-1 and CPMUs 2 - 4, to better facilitate shimming, particularly at cold temperatures. The ability to shim at cryogenic temperatures necessitated the development of an in-vacuum measurement system. The details of the measurement system will be presented alongside the mechanical and cryogenic design of the undulators; including issues with the magnet foils, and the shimming procedures and tools used to reach the tight magnetic specifications at room temperature and at 77 K.
	Poster WE4P36 [1.656 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-FLS2023-WE4P36
About •	Received ※ 23 August 2023 — Revised ※ 29 August 2023 — Accepted ※ 31 August 2023 — Issued ※ 02 December 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WE4P38	Pulsed Wire Measurement of 20 mm Period Hybrid Undulator and Effects of Dispersion	undulator, experiment, laser, vacuum	218
	S.M. Khan, G. Mishra Devi Ahilya University, Indore, India M. Gehlot DESY, Hamburg, Germany
	In the pulsed wire method, a thin wire is stretched along the undulator axis with a sensor located near the undulator end. When a current flows through the wire, the Lorentz force on the wire sets up a travelling wave that is picked up by a sensor. Sensor output v. time gives the field integral v. position along the undulator length. We investigate pulsed wire measurements of field integrals and phase error of a 20 mm-period, 500 mm-long undulator and discuss variation in performance with Hall probe data, without any dispersion correction algorithm. Dispersion in the wire introduces dispersion corrected pulse lengths for the field integral measurements. Two field integrals of the undulator were measured with an accuracy close to 2 Gcm and 2 Gcm² with the Hall probe result. The contributions of dispersion to the phase error of the undulator are analyzed. The dispersion assisted phase advance in the undulator in the pulsed wire is measured with a higher slope in comparison to the Hall probe data. Dispersion limited optical phase growth along the undulator length causes period length fluctuations and yields a discrepancy in the phase error computation in comparison to Hall probe data.
DOI •	reference for this paper ※ doi:10.18429/JACoW-FLS2023-WE4P38
About •	Received ※ 22 August 2023 — Revised ※ 22 August 2023 — Accepted ※ 31 August 2023 — Issued ※ 02 December 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

WE4P36

The Cryogenic Undulator Upgrade Programme at Diamond Light Source

vacuum, undulator, MMI, cryogenics

211

Z. Patel, W. Cheng, A. George, S.H. Hale, R. Mercado, A. Ramezani Moghaddam, M. Reeves, G. Sharma, S. Tripathi
DLS, Oxfordshire, United Kingdom
M.V. Marziani
University of Cape Town, Cape Town, South Africa

Diamond Light Source has installed four 2 m long, 17.6 mm period Cryogenic Permanent Magnet Undulators (CPMUs) as upgrades for crystallography beamlines since 2020, with two more planned within the next year. The CPMUs provide 2 - 3 times more brightness and 2 - 4 times more flux than the pure permanent magnet (PPM) devices they are replacing. They have been designed, built, and measured in-house. All four have a 4 mm minimum operating gap and are almost identical in their construction: the main difference being an increase in the number of in-vacuum magnet beam support points from four to five, between CPMU-1 and CPMUs 2 - 4, to better facilitate shimming, particularly at cold temperatures. The ability to shim at cryogenic temperatures necessitated the development of an in-vacuum measurement system. The details of the measurement system will be presented alongside the mechanical and cryogenic design of the undulators; including issues with the magnet foils, and the shimming procedures and tools used to reach the tight magnetic specifications at room temperature and at 77 K.

Poster WE4P36 [1.656 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-FLS2023-WE4P36

About •

Received ※ 23 August 2023 — Revised ※ 29 August 2023 — Accepted ※ 31 August 2023 — Issued ※ 02 December 2023

Cite •

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

WE4P38

Pulsed Wire Measurement of 20 mm Period Hybrid Undulator and Effects of Dispersion

undulator, experiment, laser, vacuum

218

S.M. Khan, G. Mishra
Devi Ahilya University, Indore, India
M. Gehlot
DESY, Hamburg, Germany

In the pulsed wire method, a thin wire is stretched along the undulator axis with a sensor located near the undulator end. When a current flows through the wire, the Lorentz force on the wire sets up a travelling wave that is picked up by a sensor. Sensor output v. time gives the field integral v. position along the undulator length. We investigate pulsed wire measurements of field integrals and phase error of a 20 mm-period, 500 mm-long undulator and discuss variation in performance with Hall probe data, without any dispersion correction algorithm. Dispersion in the wire introduces dispersion corrected pulse lengths for the field integral measurements. Two field integrals of the undulator were measured with an accuracy close to 2 Gcm and 2 Gcm² with the Hall probe result. The contributions of dispersion to the phase error of the undulator are analyzed. The dispersion assisted phase advance in the undulator in the pulsed wire is measured with a higher slope in comparison to the Hall probe data. Dispersion limited optical phase growth along the undulator length causes period length fluctuations and yields a discrepancy in the phase error computation in comparison to Hall probe data.

DOI •

reference for this paper ※ doi:10.18429/JACoW-FLS2023-WE4P38

About •

Received ※ 22 August 2023 — Revised ※ 22 August 2023 — Accepted ※ 31 August 2023 — Issued ※ 02 December 2023

Cite •

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