Electron scattering at high energy (>100 MeV) has been playing as an electron femtoscope (a femtometrescale electron microscope), which provides reliable information on the internal structure of ...nuclei
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. This is because electron scattering has several features that make it an ideal probe of nuclear structure: (1) The Coulomb interaction is well understood and model independent, (2) Electrons are structureless particles, and (3) Electrons can deeply probe the internal structure of nuclei without causing any serious disturbance. By using these features, elastic and inelastic electron scattering has been applied to the study of stable nuclei, from deuteron to uranium. Elastic electron scattering is a key tool to determine the charge density distribution of nuclei, whereas inelastic electron scattering provides various information about their nuclear structure, such as their excited states, giant resonances, and nucleon properties through the single-proton knock-out reaction and other reactions
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.
The SCRIT electron scattering facility, aiming at electron scattering off short-lived unstable nuclei, has been constructed at the RIKEN RI Beam Factory. This facility consists of a racetrack ...microtron (RTM), an electron storage ring (SR2) equipped with the SCRIT system, and a low-energy RI separator (ERIS). SCRIT (self-confining radioactive isotope ion targeting) is a novel technique to form internal targets in an electron storage ring. Experiments for evaluating performance of the SCRIT system have been carried out using the stable 133Cs1+ beam and the 132Xe1+ beam supplied from ERIS. Target ions were successfully trapped in the SCRIT system with 90% efficiency at a 250mA electron beam current, and luminosity exceeding 1026/(cm2s) was maintained for more than 1s. Electrons elastically scattered from the target ions were successfully measured. Applicability of the SCRIT system to electron scattering for unstable nuclei has been established in experiments.
Silicon vertex tracker for RHIC PHENIX experiment Taketani, A.; Akiba, Y.; Apdula, N. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
11/2010, Letnik:
623, Številka:
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Journal Article
Recenzirano
The PHENIX experiment at Relativistic Heavy Ion Collider will be equipped with Silicon Vertex tracker to enhance its physics capability. There are four layers of silicon sensor to reconstruct charged ...tracks with 50μm resolution of decay length measurement. The VTX surrounds the collision point. The inner two layers and the outer two layers are composed of 30 pixel ladders and 44 stripixel ladders, respectively. We have been developing these detectors and done a performance test with 120GeV proton beam.
We aim at evaluating time evolutions of charge state distributions of target ions in internal targets formed by the self-confining RI ion target (SCRIT) technique. The charge state distribution of ...the target ions is important for optimizing the SCRIT performance, because the number of target ions escaping from the SCRIT is increasing with decreasing the mass-to-charge ratio (A/q) of the target ions. To quantitatively evaluate the charge state distribution, we developed the E-scanning method that separates target ions by their A/q using a fixed magnetic field and a scanning electric field in the E×B velocity filter. Results in the measurements with 138Ba ions, the 138Ba1+∼7+ ions trapped in the SCRIT were identified clearly, and their time evolutions were observed for the first time at a trapping time of 30 ∼ 300 ms.
•The SCRIT technique forms a internal ion target.•The charge state of target ions have a significant impact on the SCRIT performance.•We developed the E-scanning method for evaluating the detailed charge state distributions.•The time evolutions of 138Ba1+∼7+ ions trapped in the SCRIT were observed for the first time.
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