Dedicated beam position monitor pair for model-independent lattice characterization at NSLS-II

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Li, Yongjun, Ha, Kiman, Padrazo, Danny, Kosciuk, Bernard, Bacha, Belkacem, Seegitz, Michael, Rainer, Robert, Mead, Joseph, Yang, Xi, Tian, Yuke, Todd, Robert, Smaluk, Victor, Cheng, Weixing
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866911490757361664
author Li, Yongjun
Ha, Kiman
Padrazo, Danny
Kosciuk, Bernard
Bacha, Belkacem
Seegitz, Michael
Rainer, Robert
Mead, Joseph
Yang, Xi
Tian, Yuke
Todd, Robert
Smaluk, Victor
Cheng, Weixing
author_facet Li, Yongjun
Ha, Kiman
Padrazo, Danny
Kosciuk, Bernard
Bacha, Belkacem
Seegitz, Michael
Rainer, Robert
Mead, Joseph
Yang, Xi
Tian, Yuke
Todd, Robert
Smaluk, Victor
Cheng, Weixing
contents This paper reports recent lattice characterization results obtained at the National Synchrotron Light Source II (NSLS-II) storage ring, conducted without reliance on a lattice model. A pair of beam position monitors (BPMs) with bunch-by-bunch (B$\times$B) resolution, were recently installed in a section of the storage ring free of magnetic fields. The new BPM pair measured the beam, or bunch's transverse Poincaré map precisely after the beam was excited. Linear one-turn-matrices (OTM) were then derived, and from these, the 4-dimensional coupled Twiss parameters were extracted at the locations of the BPM pair. By normalizing beam oscillation amplitudes with the Twiss parameters, the global action-variables were obtained. These action-variables facilitated the measurement of the local Twiss parameters observed by other BPMs independent on lattice model. This method is general, and particularly useful in certain scenarios such as a round beam mode in a diffraction-limited light source ring. We applied it to assess both weakly and strongly coupled lattices at the NSLS-II ring. Through analysis of the strongly coupled lattice, the quadrupole tilt errors were estimated to be less than 400 \siμrad. Utilizing the BPMs' B$\times$B resolution, for the first time we observed the variations of the linear lattice along a long bunch-train.
format Preprint
id arxiv_https___arxiv_org_abs_2406_16660
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Dedicated beam position monitor pair for model-independent lattice characterization at NSLS-II
Li, Yongjun
Ha, Kiman
Padrazo, Danny
Kosciuk, Bernard
Bacha, Belkacem
Seegitz, Michael
Rainer, Robert
Mead, Joseph
Yang, Xi
Tian, Yuke
Todd, Robert
Smaluk, Victor
Cheng, Weixing
Accelerator Physics
This paper reports recent lattice characterization results obtained at the National Synchrotron Light Source II (NSLS-II) storage ring, conducted without reliance on a lattice model. A pair of beam position monitors (BPMs) with bunch-by-bunch (B$\times$B) resolution, were recently installed in a section of the storage ring free of magnetic fields. The new BPM pair measured the beam, or bunch's transverse Poincaré map precisely after the beam was excited. Linear one-turn-matrices (OTM) were then derived, and from these, the 4-dimensional coupled Twiss parameters were extracted at the locations of the BPM pair. By normalizing beam oscillation amplitudes with the Twiss parameters, the global action-variables were obtained. These action-variables facilitated the measurement of the local Twiss parameters observed by other BPMs independent on lattice model. This method is general, and particularly useful in certain scenarios such as a round beam mode in a diffraction-limited light source ring. We applied it to assess both weakly and strongly coupled lattices at the NSLS-II ring. Through analysis of the strongly coupled lattice, the quadrupole tilt errors were estimated to be less than 400 \siμrad. Utilizing the BPMs' B$\times$B resolution, for the first time we observed the variations of the linear lattice along a long bunch-train.
title Dedicated beam position monitor pair for model-independent lattice characterization at NSLS-II
topic Accelerator Physics
url https://arxiv.org/abs/2406.16660