Experimental study of the E.L.S.A. electron-beam halo

Haouat, G.; Pichoff, N.; Couillaud, C.; Crescenzo, J. Di; Joly, Simon; Sequin, S.; Striby, S.

doi:10.1063/1.48046

Cited by 4 publications

(6 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…There is an additional problem with sensitive sensors such as CCD's and especially intensified CCD's. Blooming in the CCD (charge spill to neighboring pixels) and electron avalanche in the intensifier can disrupt, or at least influence, the measurement and possibly damage the sensor [15]. Advanced charge injection device cameras do not suffer blooming and have the advantage of large intrinsic dynamic range (DR * 10 5 ) [16].…”

Section: Introductionmentioning

confidence: 99%

“…To extend the DR, a number of strategies have been suggested. One of these [15] is to initially use a neutral density (ND) filter to reduce the core intensity so that it does not saturate the camera sensor. Then the filter is removed, allowing the core intensity to saturate the camera sensor, in order to view the less intense wings of the distribution.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Beam halo imaging with a digital optical mask

Zhang

Fiorito

Shkvarunets

et al. 2012

Phys. Rev. ST Accel. Beams

View full text Add to dashboard Cite

Beam halo is an important factor in any high intensity accelerator. It can cause difficulties in the control of the beam, emittance growth, particle loss, and even damage to the accelerator. It is therefore essential to understand the mechanisms of halo formation and its dynamics. Experimental measurement of the halo distribution is a fundamental tool for such studies. In this paper, we present a new high dynamic range, adaptive masking method to image beam halo, which uses a digital micromirror-array device. This method has been thoroughly tested in the laboratory using standard optical techniques, and with an actual beam produced by the University of Maryland Electron Ring (UMER). A high dynamic range (DR $ 10 5 ) has been demonstrated with this new method at UMER and recent studies, with more intense beams, indicate that this DR can be exceeded by more than an order of magnitude. The method is flexible, easy to implement, low cost, and can be used at any accelerator or light source. We present the results of our measurements of the performance of the method and illustrative images of beam halos produced under various experimental conditions.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Beam halo imaging with a digital optical mask

Zhang

Fiorito

Shkvarunets

et al. 2012

Phys. Rev. ST Accel. Beams

View full text Add to dashboard Cite

show abstract

“…At low anode-coil currents (~15 A), there is a linear beam-spot broadening with increasing bunch charge, while, at higher anode-coil currents (>18 A), the spot size is large and almost constant with charge. The low-coil-current behaviour has been observed before and attributed to space-charge effects [3].…”

Section: A Resultsmentioning

confidence: 80%

“…Then, the halo can be properly observed by increasing amplification of the light intensifier. This method yields better results than the saturated-core method, described in reference [3], since undesirable phenomena, which can spoil observation of the halo, are eliminated and background light is considerably reduced.…”

Section: The Hole-bored Screen Methodsmentioning

confidence: 99%

“…It is a modified version of the devices used to diagnose transverse profile on the ELSA facility [2]. The setup, which has been described in detail in a previous paper [3], consists of an electron/photon conversion screen, a transport optics and a video camera. The converter, which is moved in the beam path by an actuator, is an optical transition radiation (OTR) screen.…”

Section: Experimental Techniquementioning

confidence: 99%

See 1 more Smart Citation

Halo of a high-brightness electron beam

Haouat

Pichoff

Couillaud

et al.

Proceedings Particle Accelerator Conference

Self Cite

View full text Add to dashboard Cite

The experimental study of transverse profile of the ELSA-linac electron beam has been undertaken in order to analyze the mechanisms of halo formation and development in the generation, acceleration and transport of a highintensity, high-brightness charged-particle beam. Measurements are reported in which the beam profile is observed over four to five decades. They were performed using an imaging technique in which light emitted from an optical transition radiation (OTR) screen placed in the beam path is transported through conventional optics to an intensified video camera. The electron-density distribution is shown to be dependent on the beam current, through space charge effects, initial conditions and transport configuration.

show abstract

Observation of space-charge driven beam instabilities in a radio frequency photoinjector

et al. 1997

Self Cite

View full text Add to dashboard Cite

This article describes an experimental determination of the correlated, longitudinal phase-space electron distribution produced by a radio frequency photoinjector. Measurements of the electron beam energy spectra and pulse shapes are analyzed to deduce the longitudinal phase space at the exit of the photoinjector rf cavity. Data were obtained for micro-pulse charges of 0.5, 1.0, 2.0, 3.0, 4.0, and 5.0 nC, and show different phenomena in the low-charge and high-charge regimes. At low beam charge, the uncorrelated energy spread increases with increasing charge density, while rf bunching appears to cancel any pulse-length elongation due to the space-charge forces. At high beam charge, the data show that the micro-pulse separates into three distinct sub-pulses of nearly equal charge, and with a temporal separation proportional to the relativistic plasma frequency. These effects are compared with the space-charge generated instabilities and virtual-cathode phenomena observed in lower voltage devices. The implications that these results have upon the fundamental limits of beam brightness and magnetic pulse compression limitations are discussed.

show abstract

Experimental study of the E.L.S.A. electron-beam halo

Cited by 4 publications

References 2 publications

Beam halo imaging with a digital optical mask

Beam halo imaging with a digital optical mask

Halo of a high-brightness electron beam

Observation of space-charge driven beam instabilities in a radio frequency photoinjector

Contact Info

Product

Resources

About