skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Diffusion measurement from observed transverse beam echoes

Abstract

For this research, we study the measurement of transverse diffusion through beam echoes. We revisit earlier observations of echoes in RHIC and apply an updated theoretical model to these measurements. We consider three possible models for the diffusion coefficient and show that only one is consistent with measured echo amplitudes and pulse widths. This model allows us to parameterize the diffusion coefficients as functions of bunch charge. We demonstrate that echoes can be used to measure diffusion much quicker than present methods and could be useful to a variety of hadron synchrotrons.

Authors:
ORCiD logo [1];  [2]
  1. Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States). Accelerator Physics Center
  2. Brookhaven National Lab. (BNL), Upton, NY (United States)
Publication Date:
Research Org.:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org.:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
OSTI Identifier:
1338631
Alternate Identifier(s):
OSTI ID: 1339143
Report Number(s):
FERMILAB-PUB-16-392-APC; arXiv:1610.02093
Journal ID: ISSN 2469-9888; 1490698; TRN: US1701016
Grant/Contract Number:
AC02-07CH11359; AC02-98CH10886
Resource Type:
Journal Article: Published Article
Journal Name:
Physical Review Accelerators and Beams (Online)
Additional Journal Information:
Journal Name: Physical Review Accelerators and Beams (Online); Journal Volume: 20; Journal Issue: 1; Journal ID: ISSN 2469-9888
Publisher:
American Physical Society (APS)
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS

Citation Formats

Sen, Tanaji, and Fischer, Wolfram. Diffusion measurement from observed transverse beam echoes. United States: N. p., 2017. Web. doi:10.1103/PhysRevAccelBeams.20.011001.
Sen, Tanaji, & Fischer, Wolfram. Diffusion measurement from observed transverse beam echoes. United States. doi:10.1103/PhysRevAccelBeams.20.011001.
Sen, Tanaji, and Fischer, Wolfram. Mon . "Diffusion measurement from observed transverse beam echoes". United States. doi:10.1103/PhysRevAccelBeams.20.011001.
@article{osti_1338631,
title = {Diffusion measurement from observed transverse beam echoes},
author = {Sen, Tanaji and Fischer, Wolfram},
abstractNote = {For this research, we study the measurement of transverse diffusion through beam echoes. We revisit earlier observations of echoes in RHIC and apply an updated theoretical model to these measurements. We consider three possible models for the diffusion coefficient and show that only one is consistent with measured echo amplitudes and pulse widths. This model allows us to parameterize the diffusion coefficients as functions of bunch charge. We demonstrate that echoes can be used to measure diffusion much quicker than present methods and could be useful to a variety of hadron synchrotrons.},
doi = {10.1103/PhysRevAccelBeams.20.011001},
journal = {Physical Review Accelerators and Beams (Online)},
number = 1,
volume = 20,
place = {United States},
year = {Mon Jan 09 00:00:00 EST 2017},
month = {Mon Jan 09 00:00:00 EST 2017}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1103/PhysRevAccelBeams.20.011001

Save / Share:
  • For this research, we study the measurement of transverse diffusion through beam echoes. We revisit earlier observations of echoes in RHIC and apply an updated theoretical model to these measurements. We consider three possible models for the diffusion coefficient and show that only one is consistent with measured echo amplitudes and pulse widths. This model allows us to parameterize the diffusion coefficients as functions of bunch charge. We demonstrate that echoes can be used to measure diffusion much quicker than present methods and could be useful to a variety of hadron synchrotrons.
  • We have made a direct determination of the diffusion rates in a stored, coasting antiproton beam by observing the decay rates associated with beam echoes in the longitudinal plane. The beam echoes, similar to those observed in other fields of physics, are generated by a sequential impulse excitation at harmonics of the beam revolution frequency. The echo envelope follows a characteristic response which, however, can be modified by the presence of even a very weak scattering process, permitting a sensitive determination of the longitudinal diffusion rate in the beam. {copyright} {ital 1996 The American Physical Society.}
  • Transverse beam echoes can be excited with a single dipole kick followed by a single quadrupole kick. They have been used to measure diffusion in hadron beams and have other diagnostic capabilities. Here we develop theories of the transverse echo nonlinear in both the dipole and quadrupole kick strengths. The theories predict the maximum echo amplitudes and the optimum strength parameters. We find that the echo amplitude increases with smaller beam emittance and the asymptotic echo amplitude can exceed half the initial dipole kick amplitude. We show that multiple echoes can be observed provided the dipole kick is large enough.more » The spectrum of the echo pulse can be used to determine the nonlinear detuning parameter with small amplitude dipole kicks. Simulations are performed to check the theoretical predictions. In the useful ranges of dipole and quadrupole strengths, they are shown to be in reasonable agreement.« less
  • Transverse beam echoes can be excited with a single dipole kick followed by a single quadrupole kick. They have been used to measure diffusion in hadron beams and have other diagnostic capabilities. Here we develop theories of the transverse echo nonlinear in both the dipole and quadrupole kick strengths. The theories predict the maximum echo amplitudes and the optimum strength parameters. We find that the echo amplitude increases with smaller beam emittance and the asymptotic echo amplitude can exceed half the initial dipole kick amplitude. We show that multiple echoes can be observed provided the dipole kick is large enough.more » The spectrum of the echo pulse can be used to determine the nonlinear detuning parameter with small amplitude dipole kicks. Simulations are performed to check the theoretical predictions. In the useful ranges of dipole and quadrupole strengths, they are shown to be in reasonable agreement.« less
  • A method is introduced for simultaneously measuring transverse speed and axial velocity using a single optical beam and a standard photon Doppler velocimetry (PDV) sensing architecture. This result is of particular interest given the recent, widespread use of PDV and the fact that optical velocimetry has thus far been limited to measuring motion in one dimension per probe. Further, this result demonstrates that both axial velocity data and transverse speed data (at least qualitative) may be obtained entirely through signal analysis; not requiring hardware modification. This result is immediately relevant to analyses of existing PDV data and to future effortsmore » in high-speed optical velocimetry.« less