A5076954049- Particle Accelerators and Free-Electron Lasers
- Superconducting Materials and Applications
- Particle accelerators and beam dynamics
- Particle Detector Development and Performance
- Particle physics theoretical and experimental studies
- Gyrotron and Vacuum Electronics Research
- High-Energy Particle Collisions Research
- Distributed and Parallel Computing Systems
- Magnetic confinement fusion research
- Advanced X-ray Imaging Techniques
- Advancements in Photolithography Techniques
- Laser-Plasma Interactions and Diagnostics
- Quantum Chromodynamics and Particle Interactions
- Photonic and Optical Devices
- Structural Health Monitoring Techniques
- Advanced Electrical Measurement Techniques
- Analytic Number Theory Research
- Radio Astronomy Observations and Technology
- Engineering Applied Research
- Dark Matter and Cosmic Phenomena
- Advanced Measurement and Metrology Techniques
- Antenna Design and Optimization
- Image Processing Techniques and Applications
- Medical Imaging Techniques and Applications
- International Science and Diplomacy
European Organization for Nuclear Research
2016-2025
Gladstone Institutes
2025
Princeton University
2024
Institut de Recherche sur les Lois Fondamentales de l'Univers
2024
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2024
École Polytechnique Fédérale de Lausanne
2016-2024
University of Naples Federico II
2024
University of Liverpool
2015-2023
TU Wien
2020-2022
Instituto de Física Corpuscular
2022
At the Large Hadron Collider (LHC), absolute luminosity calibrations obtained by van der Meer (vdM) method are affected mutual electromagnetic interaction of two beams. The colliding bunches experience relative orbit shifts, as well optical distortions akin to dynamic-$\beta$ effect, that both depend on transverse beam separation and must therefore be corrected for when deriving scale. In vdM regime, beam-beam parameter is small enough shift can calculated analytically. corrections...
Machine learning entails a broad range of techniques that have been widely used in Science and Engineering since decades. High-energy physics has also profited from the power these tools for advanced analysis colliders data. It is only up until recently Learning started to be applied successfully domain Accelerator Physics, which testified by intense efforts deployed this several laboratories worldwide. This case CERN, where focused devoted application beam dynamics studies at Large Hadron...
Optics measurements at the LHC are mainly based on turn-by-turn signal from hundreds of beam position monitors (BPMs). Faulty BPMs produce erroneous causing unreliable computation optics functions. Therefore, detection faulty prior to is crucial for adequate analysis. Most faults can be removed by applying traditional cleaning techniques. However, functions reconstructed cleaned data systematically exhibit a few nonphysical values which indicate presence remaining BPMs. A novel method...
New analytical formulas are derived for the rank and local discrepancy of Farey fractions. The new formula is applicable to all fractions involves sums a lower order compared searched one. This serves establish unconditional estimate that decrease with sequence. improves currently known estimates. A recursive expression also given. second any fraction from sum Mertens function, again, improving
Huntington's Disease (HD) is caused by a CAG repeat expansion in the gene encoding Huntingtin (HTT ) . While normal HTT function appears impacted mutation, specific pathways unique to versus loss of are unclear. To understand impact expansion, we evaluated biological signatures knockout ( KO) those that occur from applying multi-omics, live cell imaging, survival analysis and novel feature-based pipeline study cortical neurons (eCNs) derived an isogenic human embryonic stem series (RUES2)....
The LHC is currently operating with a proton energy of 4 TeV and ${\ensuremath{\beta}}^{*}$ functions at the ATLAS CMS interaction points 0.6 m. This close to design value 7 (${\ensuremath{\beta}}^{*}=0.55\text{ }\text{ }\mathrm{m}$) represented challenge for various aspects machine operation. In particular, huge effort was put into optics commissioning an unprecedented peak $\ensuremath{\beta}$ beating around 7% achieved in high hadron collider.
Linear optics measurements and correction for charged particle beams are reviewed, including the historical path, recent trends, a comparison of different approaches, providing valuable reference years to come.
A novel scheme for the focusing of high-energy leptons in future linear colliders was proposed 2001 [P. Raimondi and A. Seryi, Phys. Rev. Lett. 86, 3779 (2001)]. This has many advantageous properties over previously studied schemes, including being significantly shorter a given energy having better bandwidth. Experimental results from ATF2 accelerator at KEK are presented that validate operating principle such by demonstrating demagnification 1.3 GeV electron beam down to below 65 nm height...
Optics stability during all phases of operation is crucial for the LHC. Tools and procedures have been developed rapid checks beta beating, dispersion, linear coupling, as well prompt optics corrections. Important errors different beam commissioning were observed locally corrected using segment-by-segment technique. The most relevant corrections at injection corroborated with dedicated magnetic measurements.
In this paper the influence of betatron coupling on transverse beam emittances is described using resonance driving terms formalism. Betatron and vertical dispersion generated by magnetic installation errors are major sources emittance. A new scheme for minimizing latter presented here, together with results from measurements carried out in 2010 at ESRF electron storage ring, which provided emittance about 4.4 pm, a record low machine. Two schemes automatic compensation introduced insertion...
Since 2015 the LHC has been operating at 6.5 TeV. In 2016 β-functions interaction points of ATLAS and CMS were squeezed to 0.4 m. This is below design β*=0.55 m 7 TeV, instrumental surpass luminosity 1034 cm−2 s−1. Achieving a lower than nominal β* possible thanks extraordinary performance LHC, in which control optics played fundamental role. Even though β-beating for virgin machine was above 100%, corrections reduced rms 1% two main experiments 2% around ring. guarantees safe operation as...
The control of the betatron coupling is importance for safe beam operation in LHC. In this article we show recent advancements methods and algorithms to measure correct coupling. benefit using a more precise formula relating resonance driving term ${f}_{1001}$ $\mathrm{\ensuremath{\Delta}}{Q}_{min}$ presented. quality measurements increased, with about factor 3, by selecting position monitor (BPM) pairs phase advances close $\frac{\ensuremath{\pi}}{2}$ through data cleaning singular value...
Optics measurement algorithms have been improved in preparation for the commissioning of LHC at higher energy, i.e., with an increased damage potential. Due to machine protection considerations energy sets tighter limits maximum excitation amplitude and total beam charge, reducing signal noise ratio optics measurements. Furthermore precision 2012 (4 TeV) was insufficient understand size measurements determine interaction point (IP) $\ensuremath{\beta}$-functions (${\ensuremath{\beta}}^{*}$)....
Recently, resonance driving terms were successfully measured in the CERN SPS and BNL RHIC from Fourier spectrum of beam position monitor (BPM) data. Based on these measurements a new analysis has been derived to extract truly local observables BPM These are called since they share some similarities with global terms. In this paper we derive analytically present experimental sextupolar RHIC. Nondestructive using ac dipoles also presented.
Proton beams were successfully steered through the entire ring of CERN Large Hadron Collider (LHC) on September 10th 2008. A reasonable lifetime was achieved for counterclockwise beam, namely beam 2, after radiofrequency capture particle bunch established. This provided unique opportunity acquiring turn-by-turn betatron oscillations a maximum 90 turns right at injection. Transverse coupling not corrected and chromaticity estimated to be large. Despite this largely constrained scenario,...
The CLIC study is exploring the scheme for an electron-positron collider with a center-of-mass energy of 3 TeV in order to make multi-TeV range accessible lepton physics. current goal project demonstrate feasibility technology by year 2010. Recently, important progress has been made concerning high-gradient accelerating structure tests and experiments beam test facility, CTF3. Several aspects are dealt through international collaborations, which considerably boosted study.
In circular machines, nonlinear dynamics can impact parameters such as beam lifetime and could result in limitations on the performance reach of accelerator. Assessing understanding these effects experiments is essential to confirm accuracy magnetic model improve machine performance. A direct measurement nonlinearities be obtained by characterizing dependency tune a function amplitude oscillations (usually defined detuning). The conventional technique excite large amplitudes with single kick...
This contribution describes the experimental program already undergoing and to be completed on High Luminosity LHC (HL-LHC) IT String, an important intermediate milestone of HL-LHC project at CERN. First, it magnet circuits String. Afterwards, different systems installed perform are detailed. The proposed tests defined for validation cryogenic system, full remote alignment powering protection schemes all magnets working in unison. strategy will allow a verification integrated system before...
Modern colliders bring into collision a large number of bunches to achieve high luminosity. The long-range beam-beam effects arising from parasitic encounters at such are mitigated by introducing crossing angle. Under these conditions, crab cavities (CC) can be used restore effective head-on collisions and thereby increase the geometric Such have been proposed for both linear circular colliders. rf operated in transverse dipole mode, which imparts on beam particles kick that varies with...
ATF2 is a final-focus test beam line which aims to focus the low emittance from ATF damping ring vertical size of about 37 nm and demonstrate nanometer level stability. Several advanced diagnostics feedback tools are used. In December 2008, construction installation were completed commissioning started, supported by an international team Asian, European, U.S. scientists. The present status first results described.