IPAC2016 - List of Authors (Xu, Y.H.)

Paper	Title	Page
MOPMR054	Double-slit Interferometer Measurements at SPEAR3	368
	C.L. Li, W.J. Zhang East China University of Science and Technology, Shanghai, People's Republic of China M.J. Boland SLSA, Clayton, Australia W.J. Corbett, M. Grinberg SLAC, Menlo Park, California, USA T.M. Mitsuhashi KEK, Ibaraki, Japan Y.H. Xu DongHua University, Songjiang, People's Republic of China W.J. Zhang University of Saskatchewan, Saskatoon, Canada
	The resolution of a conventional telescope used to image visible-light synchrotron radiation is often limited by diffraction effects. To improve resolution, the double-slit interferometer method was developed at KEK and has since become popular around the world. Based on the Van Cittert-Zernike theorem relating transverse source profile to transverse spatial coherence, the particle beam size can be inferred by recording fringe contrast as a function of interferometer slit separation. In this paper, we describe the SPEAR3 double-slit interferometer, develop a theoretical framework for the interferometer and provide experimental results. Of note the double-slit system is 'rotated' about the beam axis to map the dependence of photon beam coherence on angle.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMR054
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THPOY050	Time Response of a Gridded X-ray Beam Ionization Chamber	4220
SUPSS083	use link to see paper's listing under its alternate paper code
	Y.H. Xu, Z.H. Sun DongHua University, Songjiang, People's Republic of China D.V. Campen, W.J. Corbett SLAC, Menlo Park, California, USA C.L. Li East China University of Science and Technology, Shanghai, People's Republic of China W.J. Zhang University of Saskatchewan, Saskatoon, Canada
	Recently, Quick-Scanning Extended X-ray Absorption Spectroscopy (QEXAS) has become an important tool for in-situ characterization of materials and measurement of associated electronic structure. In this case the time response of the ionization chamber affects the measurement resolution and therefore overall performance of the QEXAS system. Common parallel-plate ionization chambers have a step-response rise time of about 0.1 sec, which does not meet the requirements of QEXAS. To speed up the response, we constructed a gridded ionization chamber with variable bias voltage and optional background gas (N2 or He, respectively). To characterize the system we used a high-frequency beam chopper upstream of the ionization chamber and a high-speed, low-noise preamplifier to measure the step response of the chamber as a function of bias voltage and background gas conditions.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOY050
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THPOY051	Upgrades to the SPEAR3 Single-Photon Bunch Measurement System	4223
	T.M. Cope, S. Allison, W.J. Corbett, Y.H. Xu SLAC, Menlo Park, California, USA
	The SPEAR3 accelerator uses a Single Photon Time-Correlated Counting (TCSPC) system to accurately measure the time profile of electron bunches circulating in the storage ring. The detection hardware uses the PicoHarp 300 TCSPC processor module initially equipped with an available Hamamatsu H7360-01 photon counting head. The H7360-01 was later replaced with a PicoQuant Hybrid-06 PMA to decrease single-photon arrival time jitter. At the same time we adopted an EPICS-based TCSPC software package developed at DIAMOND for robust data acquisition and display. In this paper we report on recent beam profile measurements and upgrades to the data acquisition software system including installation of a local EPICS IOC for real-time access to the bunch profile from SLAC's centralized Accelerator Control Room (ACR). High-level operator interface and monitoring applications developed in Python are discussed.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOY051
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Paper

Title

Page

Double-slit Interferometer Measurements at SPEAR3

368

C.L. Li, W.J. Zhang
East China University of Science and Technology, Shanghai, People's Republic of China
M.J. Boland
SLSA, Clayton, Australia
W.J. Corbett, M. Grinberg
SLAC, Menlo Park, California, USA
T.M. Mitsuhashi
KEK, Ibaraki, Japan
Y.H. Xu
DongHua University, Songjiang, People's Republic of China
W.J. Zhang
University of Saskatchewan, Saskatoon, Canada

The resolution of a conventional telescope used to image visible-light synchrotron radiation is often limited by diffraction effects. To improve resolution, the double-slit interferometer method was developed at KEK and has since become popular around the world. Based on the Van Cittert-Zernike theorem relating transverse source profile to transverse spatial coherence, the particle beam size can be inferred by recording fringe contrast as a function of interferometer slit separation. In this paper, we describe the SPEAR3 double-slit interferometer, develop a theoretical framework for the interferometer and provide experimental results. Of note the double-slit system is 'rotated' about the beam axis to map the dependence of photon beam coherence on angle.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMR054

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

THPOY050

Time Response of a Gridded X-ray Beam Ionization Chamber

4220

SUPSS083

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

Y.H. Xu, Z.H. Sun
DongHua University, Songjiang, People's Republic of China
D.V. Campen, W.J. Corbett
SLAC, Menlo Park, California, USA
C.L. Li
East China University of Science and Technology, Shanghai, People's Republic of China
W.J. Zhang
University of Saskatchewan, Saskatoon, Canada

Recently, Quick-Scanning Extended X-ray Absorption Spectroscopy (QEXAS) has become an important tool for in-situ characterization of materials and measurement of associated electronic structure. In this case the time response of the ionization chamber affects the measurement resolution and therefore overall performance of the QEXAS system. Common parallel-plate ionization chambers have a step-response rise time of about 0.1 sec, which does not meet the requirements of QEXAS. To speed up the response, we constructed a gridded ionization chamber with variable bias voltage and optional background gas (N2 or He, respectively). To characterize the system we used a high-frequency beam chopper upstream of the ionization chamber and a high-speed, low-noise preamplifier to measure the step response of the chamber as a function of bias voltage and background gas conditions.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOY050

Export •

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

THPOY051

Upgrades to the SPEAR3 Single-Photon Bunch Measurement System

4223

T.M. Cope, S. Allison, W.J. Corbett, Y.H. Xu
SLAC, Menlo Park, California, USA

The SPEAR3 accelerator uses a Single Photon Time-Correlated Counting (TCSPC) system to accurately measure the time profile of electron bunches circulating in the storage ring. The detection hardware uses the PicoHarp 300 TCSPC processor module initially equipped with an available Hamamatsu H7360-01 photon counting head. The H7360-01 was later replaced with a PicoQuant Hybrid-06 PMA to decrease single-photon arrival time jitter. At the same time we adopted an EPICS-based TCSPC software package developed at DIAMOND for robust data acquisition and display. In this paper we report on recent beam profile measurements and upgrades to the data acquisition software system including installation of a local EPICS IOC for real-time access to the bunch profile from SLAC's centralized Accelerator Control Room (ACR). High-level operator interface and monitoring applications developed in Python are discussed.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOY051

Export •

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