Proton Synchrotron Radiation Diagnostics at HERA

Kube, G.; Priebe, Gunnar; Wiebers, Ch.; Wittenburg, K.

doi:10.1063/1.2401426

Cited by 7 publications

(9 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Since the SR power emitted is proportional to the fourth power of the relativistic g, the intensity of SR from a proton beam is 13 orders of magnitude lower than that of an electron beam with the same energy and the same radius of curvature. Nonetheless, synchrotron radiation has been used for diagnostics at the highest-energy proton accelerators [6,7].…”

Section: Introductionmentioning

confidence: 99%

First results of the LHC longitudinal density monitor

Jeff

Boccardi

Bravin

et al. 2011

Nuclear Instruments and Methods in Physics Research Section A:

View full text Add to dashboard Cite

SummaryThe Large Hadron Collider (LHC) at CERN is the world's largest particle accelerator. It is designed to accelerate and collide protons or heavy ions up to the center-of-mass energies of 14TeV. Knowledge of the longitudinal distribution of particles is important for various aspects of accelerator operation, in particular to check the injection quality and to measure the proportion of charge outside the nominally filled bunches during the physics periods. In order to study this so-called ghost charge at levels very much smaller than the main bunches, a longitudinal profile measurement with a very high dynamic range is needed. A new detector, the LHC Longitudinal Density Monitor (LDM) is a single-photon counting system measuring synchrotronlight by means of an avalanche photodiode detector. The unprecedented energies reached in the LHC allow synchrotronlight diagnostics to be used with both protons and heavy ions. A prototype was installed during the 2010 LHC run and was able to longitudinally profile the whole ring with a resolution close to the target of 50 ps. On-line correction for the effects of the detector deadtime, pile-up and afterpulsing allow a dynamic range of 10 5 to be achieved. First measurements with the LDM are presented here along with an analysis of its performance and an outlook for future upgrades. The Large Hadron Collider (LHC) at CERN is the world's largest particle accelerator. It is designed to accelerate and collide protons or heavy ions up to the center-of-mass energies of 14 TeV.Knowledge of the longitudinal distribution of particles is important for various aspects of accelerator operation, in particular to check the injection quality and to measure the proportion of charge outside the nominally filled bunches during the physics periods. In order to study this so-called ghost charge at levels very much smaller than the main bunches, a longitudinal profile measurement with a very high dynamic range is needed.A new detector, the LHC Longitudinal Density Monitor (LDM) is a single-photon counting system measuring synchrotron light by means of an avalanche photodiode detector. The unprecedented energies reached in the LHC allow synchrotron light diagnostics to be used with both protons and heavy ions.A prototype was installed during the 2010 LHC run and was able to longitudinally profile the whole ring with a resolution close to the target of 50 ps. On-line correction for the effects of the detector deadtime, pile-up and afterpulsing allow a dynamic range of 10 5 to be achieved.First measurements with the LDM are presented here along with an analysis of its performance and an outlook for future upgrades.

show abstract

Section: Introductionmentioning

confidence: 99%

First results of the LHC longitudinal density monitor

Jeff

Boccardi

Bravin

et al. 2011

Nuclear Instruments and Methods in Physics Research Section A:

View full text Add to dashboard Cite

show abstract

“…Assume that ρ = i ρ i 1 i is a piecewise constant function solving (15) and for given ϕ ∈ R n multiply (15) with ϕ := i ϕ i π1 i . We obtain…”

Section: Discretization Of the Time Evolution Operator And The Genmentioning

confidence: 99%

“…The Galerkin discretization of the continuous operators T (τ ) and Q described in the theory section is one source of errors. With regard to the transition probability matrix T(τ ), the discretization of the space causes the loss of information and the loss of the Markov property 3,9,15 . Let's consider a discretization of the space into n disjoint sets A 1 , .…”

Section: A Discretization Errormentioning

confidence: 99%

Estimation of the infinitesimal generator by square-root approximation

Donati

Heida

Keller

et al. 2018

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

In recent years, for the analysis of molecular processes, the estimation of time-scales and transition rates has become fundamental. Estimating the transition rates between molecular conformations is-from a mathematical point of view-an invariant subspace projection problem. We present a method to project the infinitesimal generator acting on function space to a low-dimensional rate matrix. This projection can be performed in two steps. First, we discretize the conformational space in a Voronoi tessellation, then the transition rates between adjacent cells is approximated by the geometric average of the Boltzmann weights of the Voronoi cells. This method demonstrates that there is a direct relation between the potential energy surface of molecular structures and the transition rates of conformational changes. We will show also that this approximation is correct and converges to the generator of the Smoluchowski equation in the limit of infinitely small Voronoi cells. We present results for a two dimensional diffusion process and alanine dipeptide as a high-dimensional system.

show abstract

“…This filling scheme is created in the LHC's injector complex which consists of a sequence of preaccelerators operating with different rf frequencies and filling schemes. Longitudinal matching of the beam throughout the complex requires sophisticated rf gymnastics in which longer bunches are split into a series of shorter bunches with some empty buckets between them [3]. Some particles can however enter these nominally empty buckets forming satellite bunches adjacent to the main bunches.…”

Section: Introductionmentioning

confidence: 99%

“…Nonetheless, synchrotron radiation has been used for diagnostics at the highest-energy proton accelerators using the edge effect [6][7][8].…”

Section: Introductionmentioning

confidence: 99%

Longitudinal density monitor for the LHC

Jeff

Andersen

Boccardi

et al. 2012

Phys. Rev. ST Accel. Beams

View full text Add to dashboard Cite

The longitudinal density monitor (LDM) is primarily intended for the measurement of the particle population in nominally empty rf buckets. These so-called satellite or ghost bunches can cause problems for machine protection as well as influencing the luminosity calibration of the LHC. The high dynamic range of the system allows measurement of ghost bunches with as little as 0.01% of the main bunch population at the same time as characterization of the main bunches. The LDM is a single-photon counting system using visible synchrotron light. The photon detector is a silicon avalanche photodiode operated in Geiger mode, which allows the longitudinal distribution of the LHC beams to be measured with a resolution of 90 ps. Results from the LDM are presented, including a proposed method for constructing a 3-dimensional beam density map by scanning the LDM sensor in the transverse plane. In addition, we present a scheme to improve the sensitivity of the system by using an optical switching technique.

show abstract

Proton Synchrotron Radiation Diagnostics at HERA

Cited by 7 publications

References 5 publications

First results of the LHC longitudinal density monitor

First results of the LHC longitudinal density monitor

Estimation of the infinitesimal generator by square-root approximation

Longitudinal density monitor for the LHC

Contact Info

Product

Resources

About