Search results for "spectrometer"
showing 10 items of 751 documents
Hypernuclear Spectroscopy at JLab Hall C
2010
Abstract Since the 1st generation experiment, E89-009, which was successfully carried out as a pilot experiment of (e,e'K+) hypernuclear spectroscopy at JLab Hall C in 2000, precision hypernuclear spectroscopy by the (e,e'K+) reactions made considerable progress. It has evolved to the 2nd generation experiment, E01-011, in which a newly constructed high resolution kaon spectrometer (HKS) was installed and the “Tilt method” was adopted in order to suppress large electromagnetic background and to run with high luminosity. Preliminary high-resolution spectra of 7 Λ He and 28 Λ Al together with that of 12 Λ B that achieved resolution better than 500 keV(FWHM) were obtained. The third generation…
Search for new physics in beta-neutrino correlations with the WITCH spectrometer
2002
The WITCH (Weak Interaction Trap for CHarged particles) experiment is a retardation spectrometer coupled to a Penning trap and measures the beta-neutrino angular correlation via the shape of the recoil energy spectrum. The present form of the Standard Model describes weak processes in terms of vector and axial-vector type interactions, but the possible presence of scalar and tensor interactions is not yet ruled out. The main aim of this experiment is a test of the Standard Model for possible admixture of scalar and tensor currents. (C) 2002 Elsevier Science B.V. All rights reserved.
Beta decay studies with the total absorption technique: past, present and future
2005
Measurements of beta decay reduced transition probabilities are particularly relevant in nuclei far from the stability line. It has been demonstrated that a proper measurement of this quantity requires the use of the total absorption technique, which has become a reliable tool in recent years, thanks to the increased efficiency of the associated spectrometers and the development of new analysis techniques. In this paper, we present a brief history of the past and present use of these detectors and how they might be developed in the future.
A new upper limit of the electron anti neutrino rest mass from tritium β-decay
1993
Abstract A new upper limit of the electron anti neutrino rest mass has been deduced from the tritium β-decay spectrum. A source of molecular tritium has been investigated with a new solenoid retarding spectrometer. The results are m ν ϵ 2 = −38.8 ± 34.1 stat ± 15.1 syst (eV) 2 /c 4 from which we conclude m ν ϵ ≤ 7.2 eV/c 2 with 95% c.l. Our β-endpoint corresponds to a 3H-3He atomic mass difference of Δm( 3 H- 3 He) = 18590.8 ± 3 eV/c 2 (1σ) .
Low-lying excited states in the neutron-deficient isotopes163Os and165Os
2013
Excited states in the neutron-deficient isotopes Os-163 and Os-165 were identified using the JUROGAM and GREAT spectrometers in conjunction with the RITU gas-filled separator. The Os-163 and Os-165 nuclei were populated via the Cd-106(Ni-60,3n) and Mo-92(Kr-78,2p3n) reactions at bombarding energies of 270 MeV and 357 MeV, respectively. Gamma-ray emissions from these nuclei have been established unambiguously using the recoil-decay tagging technique and a coincidence analysis has allowed level schemes to be established. These results suggest that the yrast states are based upon negative-parity configurations originating from the f(7/2) and h(9/2) orbitals.
Λ polarization in associated K+–Λ electro-production
1999
Abstract The result of a feasibility study to measure the Λ polarization in associated K + – Λ electro-production is presented. This measurement was performed in the experimental Hall C at Jefferson Lab. The scattered electron was detected in the HMS spectrometer, and the electro-produced kaon and the proton from the Λ → pπ − decay were both detected in the SOS spectrometer. This quantity is very sensitive to the elementary p ( e , e ′ K ) Λ process and gives information on resonance production, and Regge exchange, among others. The result presented was measured at Q 2 =1.50 (GeV/c) 2 and cos θ Kγ CM =14°. The limits of the Λ polarization, with respect to the p γ × p K axis, were found to b…
T2-beta-spectroscopy at KATRIN and the challenge of controlling the electrostatic potentials
2013
Abstract The KATRIN-Collaboration at KIT-Karlsruhe is setting up a huge electrostatic spectrometer in order to search for the absolute value of the neutrino mass from the beta-spectrum of molecular tritium with a sensitivity limit of 0.2 eV. Apart from high intensity, high resolution and low background, this goal requires control of the 18.6 kV filter potential on the ppm level. The paper starts with discussing the impact of uncertainties of beta-endpoint, energy loss and filter potential on the uncertainty of the neutrino mass. Then it describes the various measures for controlling the applied high voltage as well as the potential distribution within the spectrometer and the gaseous tritiu…
The three-spectrometer setup for (e,e'x) coincidence experiments at the Mainz microtron MAMI
1995
A setup of three high-resolution magnetic spectrometers has been built up as the central facility for the precise determination of electron scattering cross sections in coincidence with hadrons. The operational experiencies with two of the spectrometers, A and B, demonstrate that both spectrometers exceed the specifications. With A and B, a series of ( e, e′x ) coincidence experiments were successfully performed. The third spectrometer, C, will be ready for operation in late autumn 1994.
Probing hypernuclei at $$ \bar P $$ anda and at MAMI-C
2008
Spectroscopy of Λ hypernuclei has recently become one of the most valuable tools for the experimental investigation of strangeness nuclear physics. Several new approached are being pursued currently: In Mainz, the Microtron MAMI has been upgraded to 1.5 GeV electron beam energy and will be used to produce strange hadronic systems in the near future. The KaoS spectrometer is being installed for large acceptance, high resolution strangeness reaction spectroscopy at the existing spectrometer facility. The Mainz hypernuclei research programme will be complemented by experiments on multi-strange systems at the planned FAIR facility at GSI. The γ-ray spectroscopy of double Λ hypernuclei produced …
The Experimental Program of the MAMI-Project
1992
At Mainz university, a 100% duty-factor electron accelerator for beam current and energy up to 100 µA and 855 MeV,respectively, has become operational recently, the Mainz Microtron MAMI. The experimental program is based on three major equipments which are built up and will be run by three facility-oriented collaborations. Collaboration A1 is centered around a magnetic spectrometer setup and will do experiments with virtual photons. For experiments with real photons collaboration A2 runs a high-efficiency tagger. Collaboration A3 sets up a polarized electron source in order to exploit the polarization degrees of freedom.