scholarly journals The Meson Production Targets in the high energy beamline of HIPA at PSI

2021 ◽  
Author(s):  
Daniela Kiselev ◽  
Pierre-André Duperrex ◽  
Sven Jollet ◽  
Stefan Joray ◽  
Daniel Laube ◽  
...  
Keyword(s):  
Meson Production ◽  
High Energy ◽  
Thick Target ◽  
Proton Accelerator ◽  
Beam Power ◽  
Graphite Target ◽  
Beam Dump ◽  
Neutron Spallation Source ◽  
Spallation Source ◽  
Paul Scherrer

Two target stations in the 590 MeV proton beamline of the High Intensity Proton Accelerator (HIPA) at the Paul Scherrer Institut (PSI) produce pions and muons for seven secondary beamlines, leading to several experimental stations. The two target stations are 18 m apart. Target M is a graphite target with an effective thickness of 5 mm, Target E is a graphite wheel with a thickness of 40 mm or 60 mm. Due to the spreading of the beam in the thick target, a high power collimator system is needed to shape the beam for further transport. The beam is then transported to either the SINQ target, a neutron spallation source, or stopped in the beam dump, where about 450 kW beam power is dissipated. Targets, collimators and beam dumps are described.

Preliminary Design of a Beam Dump for the High-Energy Proton Accelerator of PEFP

2008 ◽  
Vol 52 (9(3)) ◽  
pp. 799-804
Author(s):  
Jiho Kim ◽  
Do Heon Kim ◽  
Wan Young Maeng ◽  
Choong-Sup Gil
Keyword(s):  
High Energy ◽  
Proton Accelerator ◽  
Preliminary Design ◽  
High Energy Proton ◽  
Beam Dump ◽  
Energy Proton

Assessment of shutdown dose rates at the ESS target cooling system using SCALE6.2

2020 ◽  
Vol 22 (2-3) ◽  
pp. 309-318
Author(s):  
Amalia Chambon ◽  
Esben Klinkby ◽  
Leif Emås ◽  
Bent Lauritzen
Keyword(s):  
Dose Rate ◽  
Source Term ◽  
Cooling System ◽  
High Energy ◽  
Beam Power ◽  
Robot Arm ◽  
Robotic Arms ◽  
Dose Rates ◽  
Spallation Source ◽  
Conservative Estimation

The production of high-energy neutrons at the European Spallation Source through the spallation process may cause an erosion of the tungsten target. The eroded particles could be released into the target helium cooling system which contains four kind of filters. Among them, the auxiliary filters called “getters” are designed to capture volatile elements and remaining dust. In this work, the ORNL’s SCALE6.2 modelling and simulation suite for nuclear safety analysis is applied to assess shutdown dose rates and determine if added shielding and/or robotic arms are needed for their maintenance. SCALE6.2 is well adapted to treat this problem as it allows for isotope selection regarding source term calculation. Dose rates are determined by an ORIGEN2 source term and a MAVRIC shielding sequence calculation. As SCALE6.2 is non-standard software for ESS, the results are verified against MCNP, which is the baseline tool for neutronics analysis at ESS. Dose rate calculations show that additional shielding and/or robot arm are not needed to remove the getters after 3 months of cooling time, following 5400 h of operation at 5 MW beam power. At a distance of 1 mm from the getter, the dose rate is 0.2 mSv/h in the most conservative estimation.

Measurement and analysis of induced activities in concrete irradiated using high-energy neutrons at KENS neutron spallation source facility

2005 ◽  
Vol 115 (1-4) ◽  
pp. 623-629 ◽  
Author(s):  
Koji Oishi ◽  
Noriaki Nakao ◽  
Kazuaki Kosako ◽  
Hiroshi Yamakawa ◽  
Hiroshi Nakashima ◽  
...  
Keyword(s):  
High Energy ◽  
Neutron Spallation Source ◽  
Measurement And Analysis ◽  
Spallation Source

scholarly journals Fermilab proton accelerator complex status and improvement plans

2017 ◽  
Vol 32 (16) ◽  
pp. 1730012 ◽  
Author(s):  
Vladimir Shiltsev
Keyword(s):  
Particle Physics ◽  
High Energy ◽  
Proton Accelerator ◽  
Beam Power ◽  
High Energy Particle ◽  
Accelerator Complex ◽  
Fixed Target Experiments ◽  
Superconducting Rf ◽  
Extensive Program ◽  
And Performance

Fermilab carries out an extensive program of accelerator-based high energy particle physics research at the Intensity Frontier that relies on the operation of 8 GeV and 120 GeV proton beamlines for a number of fixed target experiments. Routine operation with a world-record 700 kW of average 120 GeV beam power on the neutrino target was achieved in 2017 as a result of the Proton Improvement Plan (PIP) upgrade. There are plans to further increase the power from 900–1000 kW. The next major upgrade of the FNAL accelerator complex, called PIP-II, is under development. It aims at 1.2 MW beam power on target at the start of the LBNF/DUNE experiment in the middle of the next decade and assumes replacement of the existing 40 years old 400 MeV normal-conducting Linac with a modern 800 MeV superconducting RF linear accelerator. There are several concepts to further double the beam power to [Formula: see text] 2.4 MW after replacement of the existing 8 GeV Booster synchrotron. In this review, we discuss current performance of the Fermilab proton accelerator complex, the upgrade plans for the next two decades and the accelerator R&D program to address cost and performance risks for these upgrades.

Accelerator Waste: A New Challenge for Radioanalytics

2007 ◽  
Author(s):  
Dorothea Schumann ◽  
Michael Wohlmuther ◽  
Jo¨rg Neuhausen
Keyword(s):  
Chemical Separation ◽  
Proton Accelerator ◽  
Accelerator Facility ◽  
Beam Dump ◽  
New Radio ◽  
Urgent Task ◽  
Theoretical Predictions ◽  
Paul Scherrer

The Paul Scherrer Institute (PSI) at Villigen (Switzerland) operates the most powerful accelerator facility in Europe. Due to the increasing quantities of accelerator waste with almost unknown radionuclide inventory, the development of new radio-analytical methods is an urgent task. Besides the characterization by γ-measurements and dose rate determinations, also the investigation of long-lived radionuclides, being probably essential for a final disposal, is required from Swiss authorities. Chemical separation is necessary for the determination of the majority of these isotopes. As a representive example for such studies, the analytics of a beam dump assembly is introduced. Samples were taken from the target E beam dump station from the 590 MeV proton accelerator facility. The content of several radionuclides with half-lives between 2 and 107 years was determined by γ-spectrometry and, after chemical separation, by Liquid Scintillation Counting (LSC) as well as Accelerator Mass Spectrometry (AMS). The results are compared with theoretical predictions. Long-term object of these studies is the elaboration of nuclide vectors, which allow the estimation of nuclide inventories by simple calculations.

Mechanical Spectroscopy Investigation of Liquid Pb-Bi Alloys

2012 ◽  
Vol 184 ◽  
pp. 434-439 ◽  
Author(s):  
Roberto Montanari ◽  
Alessandra Varone
Keyword(s):  
Distribution Functions ◽  
X Ray Diffraction ◽  
Mechanical Spectroscopy ◽  
X Ray ◽  
Neutron Spallation Source ◽  
Driven System ◽  
Spallation Source ◽  
Accelerator Driven System ◽  
The Mean ◽  
Diffraction Patterns

Liquid Pb–Bi eutectic alloy has been selected as coolant and neutron spallation source for the development of MYRRHA, an accelerator driven system. The alloy has been characterized in liquid state from melting (125 °C) to 650 °C by mechanical spectroscopy. Experiments have been carried out using hollow reeds of austenitic stainless steel filled with the Pb-Bi alloy and sealed at the extremities. From 350 °C to 520 °C modulus shows a remarkable drop accompanied by a broad internal friction maximum. In the same temperature range radial distribution functions, determined from X-ray diffraction patterns, evidenced variations of the mean distance between the 1st nearest neighbour atoms. The anelastic phenomena have been attributed to a structural re-arrangement of liquid metal. For comparison, other alloys of the Pb-Bi system with hypo-eutectic composition have been investigated.

High-Energy Meson Production

1954 ◽  
Vol 93 (1) ◽  
pp. 215-226 ◽  
Author(s):  
N. M. Duller ◽  
W. D. Walker
Keyword(s):  
Meson Production ◽  
High Energy

scholarly journals The starburst galaxy NGC 253 revisited by H.E.S.S. and Fermi-LAT

2018 ◽  
Vol 617 ◽  
pp. A73 ◽  
Author(s):  
◽  
H. Abdalla ◽  
F. Aharonian ◽  
F. Ait Benkhali ◽  
E. O. Angüner ◽  
...  
Keyword(s):  
Spectral Index ◽  
Power Law ◽  
Cosmic Ray ◽  
High Energy ◽  
Thick Target ◽  
Starburst Galaxy ◽  
Particle Accelerators ◽  
Power Law Distribution ◽  
Particle Population ◽  
Measurement Uncertainties

Context. NGC 253 is one of only two starburst galaxies found to emit γ-rays from hundreds of MeV to multi-TeV energies. Accurate measurements of the very-high-energy (VHE; E > 100 GeV) and high-energy (HE; E > 60 MeV) spectra are crucial to study the underlying particle accelerators, probe the dominant emission mechanism(s) and to study cosmic-ray interaction and transport. Aims. The measurement of the VHE γ-ray emission of NGC 253 published in 2012 by H.E.S.S. was limited by large systematic uncertainties. Here, the most up to date measurement of the γ-ray spectrum of NGC 253 is investigated in both HE and VHE γ-rays. Assuming a hadronic origin of the γ-ray emission, the measurement uncertainties are propagated into the interpretation of the accelerated particle population. Methods. The data of H.E.S.S. observations are reanalysed using an updated calibration and analysis chain. The improved Fermi–LAT analysis employs more than 8 yr of data processed using pass 8. The cosmic-ray particle population is evaluated from the combined HE–VHE γ-ray spectrum using NAIMA in the optically thin case. Results. The VHE γ-ray energy spectrum is best fit by a power-law distribution with a flux normalisation of (1.34 ± 0.14stat ± 0.27sys) × 10−13 cm−2 s−1 TeV1 at 1 TeV – about 40% above, but compatible with the value obtained in Abramowski et al. (2012). The spectral index Γ = 2.39 ± 0.14stat ± 0.25sys is slightly softer than but consistent with the previous measurement within systematic errors. In the Fermi energy range an integral flux of F(E > 60 MeV) = (1.56 ± 0.28stat ± 0.15sys) × 10−8 cm−2 s−1 is obtained. At energies above ∼3 GeV the HE spectrum is consistent with a power-law ranging into the VHE part of the spectrum measured by H.E.S.S. with an overall spectral index Γ = 2.22 ± 0.06stat. Conclusions. Two scenarios for the starburst nucleus are tested, in which the gas in the starburst nucleus acts as either a thin or a thick target for hadronic cosmic rays accelerated by the individual sources in the nucleus. In these two models, the level to which NGC 253 acts as a calorimeter is estimated to a range of fcal = 0.1 to 1 while accounting for the measurement uncertainties. The presented spectrum is likely to remain the most accurate measurements until the Cherenkov Telescope Array (CTA) has collected a substantial set of data towards NGC 253.

scholarly journals Studying neutron structure at Jefferson Lab through electron scattering off the deuteron, using CLAS12 and the Central Neutron Detector

2020 ◽  
Vol 1643 (1) ◽  
pp. 012191
Author(s):  
Paul Naidoo ◽  
Daria Sokhan ◽  
Pierre Chatagnon ◽  
Silvia Niccolai ◽  
Katheryne Price
Keyword(s):  
Neutron Detector ◽  
Meson Production ◽  
Deeply Virtual Compton Scattering ◽  
Virtual Compton Scattering ◽  
High Energy ◽  
Neutral Meson ◽  
Deuteron Target ◽  
Jefferson Lab ◽  
3D Tomography ◽  
Large Acceptance

Abstract Generalised Parton Distributions (GPDs) offer a way of imaging nucleons through 3D tomography. They can be accessed experimentally in processes such as Deeply Virtual Compton Scattering (DVCS) and Deeply Virtual Meson Production (DVMP), where a high energy electron scatters from a quark inside a nucleon and a high energy photon or meson is produced as a result. Jefferson Lab has recently completed its energy upgrade and Hall B houses the new, large-acceptance CLAS12 detector array optimised for measurements of DVCS and DVMP in the newly accessible kinematic regime. Measurements on the proton and neutron are complementary and both are necessary to facilitate access to the full set of GPDs and enable their flavour separation. Neutron DVCS and DVMP are possible with the use of a deuteron target – the first CLAS12 experiment with which has started taking data this year. To enable exclusive reconstruction of DVCS and neutral-meson DVMP, a dedicated detector for recoiling neutrons – the Central Neutron Detector (CND) – was integrated into CLAS12. We present the first CLAS12 deuteron-target experiment, with a focus on the performance of the CND.

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