Search results for "Physics::Accelerator Physics"
showing 10 items of 1235 documents
The Endcap Disc DIRC detector of PANDA
2019
Abstract At the international FAIR laboratory, an upcoming significant enlargement of the GSI installations near Darmstadt, Germany, the PANDA antiproton experiment will investigate fundamental questions of hadron physics in the charm quark energy range. Antiprotons in the 1.5 to15 GeV/c momentum range will interact with gas jet or pellet fixed targets. The Endcap Disc DIRC (Detection of Internally Reflected Cherenkov light) covers the forward endcap solid angle of the PANDA target spectrometer to positively identify charged kaons. Monte-Carlo simulations indicate that from 1 up to 4 GeV/c one can achieve kaon–pion separation with a separation power of at least 3 standard deviations. For th…
Radiation damage of heavy crystalline detector materials by 24GeV protons
2013
Abstract Samples of three heavy crystalline materials: PbWO4, Bi4Si3O12, and PbF2 were irradiated in a high-intensity 24 GeV proton beam at the CERN PS to fluencies of 3.8×1013 protons/cm2. The optical transmission radiation damage was measured and all crystals show a shift of the cutoff in the transmission spectrum that is not observed when the crystals are irradiated with γ radiation. This shift of the cutoff under proton irradiation seems to be a general property of the heavy crystalline materials. A mechanism for this proton-induced transmission damage is discussed.
Search for heavy charged long-lived particles in proton–proton collisions at s=13TeV using an ionisation measurement with the ATLAS detector
2019
This Letter presents a search for heavy charged long-lived particles produced in proton-proton collisions at root s= 13 TeV at the LHC using a data sample corresponding to an integrated luminosity ...
Decay pion spectroscopy: a new approach
2019
We propose a new experiment for decay pion spectroscopy of light hypernuclei at electron- and proton-beam facilities, using the recoil distance technique for separation of produced hypernuclei and a magnetic spectrometer for precise measurement of the decay pion momentum. Low-pressure MWPCs are advocated for low-energy recoil detection as they provide position and time information and are highly insensitive to gamma-ray and electron background. The position and timing characteristics of such a recoil detector were studied using ~5 MeV {\alpha}-particles. By using the present proposed approach the rate of the detected hypernuclei can be increased by one-to-two orders of magnitude compared to…
Development and test of iron-free quadrupole lenses with high magnetic flux densities
2003
Abstract Iron-free magnetic quadrupole lenses have been developed for the focusing of energetic bunched heavy-ion beams. These devices are operated in a pulsed mode and provide very strong magnetic fields. A magnetic flux density of more than 14 T has been reached in a 100 mm long quadrupole with a 20 mm wide aperture, which corresponds to a magnetic flux density of ∼1400 T/m. The pulse duration of the applied electric current is approximately 300 μs with a flat top of several μs. The calculated and measured field properties of the quadrupoles are presented. In a first test experiment with a fast-extracted 650 MeV/u 197 Au 79+ beam (bunch length ∼500 ns) at GSI the focusing properties could…
The decay of $^{31}$Ar
1990
10 pages, 1 table, 4 figures.
Physical mechanism of the linear beam-size effect at colliders
1996
We present qualitative but precise description of the linear beam-size effect predicted for the processes in which unstable but long--living particles collide with each other. We derive physically pronounced equation for the events rate which proves that the linear beam-size effect corresponds to the scattering of one beam of particles on the decay products of the other. We compare this linear beam-size effect with the known logarithmic beam-size effect measured in the experiments on a single bremsstrahlung at VEPP-4 and HERA.
A high power liquid hydrogen target for the Mainz A4 parity violation experiment
2005
We present a new powerful liquid hydrogen target developed for the precise study of parity violating electron scattering on hydrogen and deuterium. This target has been designed to have minimal target density fluctuations under the heat load of a 20$\mu$A CW 854.3 MeV electron beam without rastering the electron beam. The target cell has a wide aperture for scattered electrons and is axially symmetric around the beam axis. The construction is optimized to intensify heat exchange by a transverse turbulent mixing in the hydrogen stream, which is directed along the electron beam. The target is constructed as a closed loop circulating system cooled by a helium refrigerator. It is operated by a …
Contact Interactions with Polarized Beams at HERA
1998
The discovery potential of the HERA collider, with and without polarized beams, for electron-quark contact interactions in neutral current scattering is reviewed. The measurement of spin asymmetries in the polarized case could give crucial information on the chiral structure of new interactions.
A direct determination of the proton-electron mass ratio
1978
The cyclotron resonance of protons and electrons in a magnetic field of 5.7 Tesla produced by a superconducting solenoid has been measured. Protons and electrons were alternately confined in an electrostatic quadrupole trap. The quotient of the cyclotron frequencies provides a first direct determination of the proton-electron mass ratio. The result ofM p /M e =1836.1502(53) agrees with other more precise but indirect determinations of this quantity.