Several epidemiological and animal studies have suggested that polyphenols, a group of secondary plant metabolites occurring mainly in the plant kingdom, may have a protective effect against some ...chronic degenerative diseases such as cancer. Polyphenols are part of the human diet, being present in vegetal food and beverages. Among them, an olive biophenol named hydroxytyrosol 2-(3,4- dihydroxyphenyl)ethanol, HTyr has recently received particular attention because of its antioxidant, antiproliferative, pro-apoptotic, and anti-inflammatory activities, which have the potential to specifically counteract all cancer hallmarks, thus representing the expectant biological activities underlying the anti-tumor properties of this polyphenol. After a description of the synthetic procedures to prepare pure HTyr, this review takes into consideration the chemopreventive and chemotherapeutic potential of HTyr as the result of its antioxidant, antiproliferative and anti-inflammatory activities. In particular, the review is focused on the current knowledge of the main cellular and molecular mechanisms used by HTyr to affect carcinogenesis, highlighting the specific oncogenic and inflammatory signaling pathways potentially targeted by HTyr.
Design of the proton and electron transfer lines for AWAKE Run 2c Ramjiawan, R.; Bencini, V.; Burrows, P.N. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2023, Letnik:
1049
Journal Article
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The Advanced Wakefield (AWAKE) Run 1 experiment, which concluded in 2018, achieved electron acceleration to 2GeV via plasma wakefield acceleration driven by 400GeV, self-modulated proton bunches ...extracted from the CERN SPS. The Run 2c phase of the experiment aims to advance these results by demonstrating acceleration up to about 10GeV while preserving the quality of the accelerated electron beam. For Run 2c, the Run 1 proton transfer line will be reconfigured to shift the first plasma cell 40m longitudinally and a second plasma cell will be added 1m downstream of the first. In addition, a new 150MeV beamline will be required to inject a witness electron beam, with a beam size of several microns, into the second plasma cell to probe the accelerating fields. Proposed adjustments to the proton transfer line and the design of the 150MeV electron transfer line are detailed in this paper.
We give direct experimental evidence for the observation of the full transverse self-modulation of a long, relativistic proton bunch propagating through a dense plasma. The bunch exits the plasma ...with a periodic density modulation resulting from radial wakefield effects. We show that the modulation is seeded by a relativistic ionization front created using an intense laser pulse copropagating with the proton bunch. The modulation extends over the length of the proton bunch following the seed point. By varying the plasma density over one order of magnitude, we show that the modulation frequency scales with the expected dependence on the plasma density, i.e., it is equal to the plasma frequency, as expected from theory.
The ENUBET project is aimed at designing and experimentally demonstrating the concept of monitored neutrino beams. These novel beams are enhanced by an instrumented decay tunnel, whose detectors ...reconstruct large-angle charged leptons produced in the tunnel and give a direct estimate of the neutrino flux at the source. These facilities are thus the ideal tool for high-precision neutrino cross-section measurements at the GeV scale because they offer superior control of beam systematics with respect to existing facilities. In this paper, we present the first end-to-end design of a monitored neutrino beam capable of monitoring lepton production at the single particle level. This goal is achieved by a new focusing system without magnetic horns, a 20 m normal-conducting transfer line for charge and momentum selection, and a 40 m tunnel instrumented with cost-effective particle detectors. Employing such a design, we show that percent precision in cross-section measurements can be achieved at the CERN SPS complex with existing neutrino detectors.
The main physics program of the CERN Super Proton Synchrotron (SPS) is dedicated to the fixed target physics experiments hosted in the North experimental Area (NA). Protons are delivered to the NA ...via third-integer resonant slow extraction over an almost 5 s flattop. In order to maximize the usable intensity delivered to the experiments, the flux of extracted particles should be kept as constant as possible. This is a very general requirement for fixed target experiments served by synchrotrons. Power supply ripples are a well-known issue in resonant slow extraction, affecting the quality of the spill. A long-standing effort is ongoing at CERN to characterize the SPS slow extraction frequency response to its main power supplies. In this paper, beam dynamics simulations are employed to understand and characterize the process, combined with dedicated beam based measurements.
We present a method to measure the transverse size and position of an electron or proton beam, close to the injection point in plasma wakefields, where other diagnostics are not available. We show ...that transverse size measurements are in agreement with values expected from the beam optics with a<10%uncertainty. We confirm the deflection of the low-energy (∼18MeV) electron beam trajectory by Earth’s magnetic field. This measurement can be used to correct for this effect and set proper electron bunch injection parameters. The advanced wakefield experiment at CERN (AWAKE) relies on these measurements for optimizing electron injection.
The Advanced Wakefield (AWAKE) Experiment is a proof-of-principle experiment demonstrating the acceleration of electron beams via proton-driven plasma wakefield acceleration. AWAKE Run 2 aims to ...build on the results of Run 1 by achieving higher energies with an improved beam quality. As part of the upgrade to Run 2, the existing proton and electron beamlines will be adapted and a second plasma cell and new 150-MeV electron beamline will be added. The specification for this new 150-MeV beamline will be challenging as it will be required to inject electron bunches with micron-level beam size and stability into the second plasma cell while being subject to tight spatial constraints. In this paper, we describe the techniques used (e.g., numerical optimizers and genetic algorithms) to produce the design of this electron line. We present a comparison of the methods used in this paper with other optimization algorithms commonly used within accelerator physics. Operational techniques are also studied including steering and alignment methods utilizing numerical optimizers and beam measurement techniques employing neural networks. We compare the performance of algorithms for online optimization and beam-based alignment in terms of their efficiency and effectiveness.
Abstract
A key aspect of the LHC Injectors Upgrade project is the connection of the PSB to the newly built Linac4 and the related installation of a new 160 MeV charge-exchange injection system. The ...new injection system was commissioned in winter 2020/21 and is now used operationally to tailor the transverse characteristics for the various beam types at CERN, such as high-intensity fixed target beams, LHC single bunch beams, and high-brightness beams for LHC. This contribution outlines the different injection strategies for producing the various beam types and discusses the application of numerical optimization algorithms to adjust injection settings in operation efficiently.
Abstract
The CERN SPS injection kicker magnets (MKP) were developed in the 1970’s, before beam power deposition was considered an issue. There are two types of these magnets in the SPS: MKP-S (small ...aperture) and MKP-L (large aperture) versions. The MKP-L magnets are very lossy from a beam impedance perspective: this would be an issue during SPS operation with the higher intensity beams needed in the future for HL-LHC. Hence, a beam screen has been developed, which is inserted in the aperture of each MKP-L module. The screen consists of silver fingers applied to alumina U-shaped chambers: the fingers have been optimized to achieve both adequately low beam induced power deposition and good high voltage (HV) behaviour. A surface coating, with a low secondary electron yield, is applied to the inner surface of the alumina chambers to reduce dynamic vacuum. The low-impedance MKP-L has been extensively HV tested in the lab before installation in the SPS. This paper briefly presents the design and focuses on the operational experience in the SPS, including heating and vacuum.
Losses and component activation are limiting performance factors for slow extraction with high-power applications, and new techniques of loss-reduction, such as bent crystals, require a stable and ...narrow separatrix angular spread. Conventional tune-sweep slow extraction results in an optics change and an accompanying separatrix rotation through the spill. This can be compensated by a dynamic closed-orbit bump, but requires a high level of complexity for setting up and monitoring. For the Super Proton Synchrotron (SPS), a simpler and powerful new extraction technique has been developed and deployed, providing a mechanism to fix the machine optics and hence separatrix completely through the spill. The technique with the name constant optics slow extraction (COSE) relies on high chromaticity and scaling all machine settings with beam rigidity following the momentum distribution of the beam. In this paper we describe the new COSE concept and its successful operational deployment in the SPS during the 2018 run.
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