Search results for "beam [electron]"
showing 10 items of 433 documents
A linear radiofrequency ion trap for accumulation, bunching, and emittance improvement of radioactive ion beams
2000
An ion beam cooler and buncher has been developed for the manipulation of radioactive ion beams. The gas-filled linear radiofrequency ion trap system is installed at the Penning trap mass spectrometer ISOLTRAP at ISOLDE/CERN. Its purpose is toaccumulate the 60-keV continuous ISOLDE ion beam with high efficiency and to convert it into low-energy low-emittance ion pulses. The efficiency was found to exceed 10\,\% in agreement with simulations. A more than 10-fold reduction of the ISOLDE beam emittance can be achieved. The system has been used successfully for first on-line experiments. Its principle, setup and performance will be discussed. An ion beam cooler and buncher has been developed fo…
Ion source and low energy beam transport prototyping for a single-ended heavy ion ToF-ERDA facility
2023
We present the status of the ion source and low energy beam transport prototyping activities for a heavy ion time-of-flight elastic recoil detection analysis (ToF-ERDA) equipment, designed to accelerate a flux of 1–10 particle nano-Ampere of 40Ar6-12+ ions to 3–6 MeV energy for depth profiling of light elements. The prototype injector consists of a novel permanent magnet electron cyclotron resonance ion source CUBE-ECRIS with a minimum-B quadrupole field topology, and a 90° permanent magnet dipole with adjustable field strength for charge state selection. We report experimentally measured argon beam currents as a function of the applied microwave power and ion source potential to demonstrat…
Development of procedures for programmable proximity aperture lithography
2013
Abstract Programmable proximity aperture lithography (PPAL) with MeV ions has been used in Jyvaskyla and Chiang Mai universities for a number of years. Here we describe a number of innovations and procedures that have been incorporated into the LabView-based software. The basic operation involves the coordination of the beam blanker and five motor-actuated translators with high accuracy, close to the minimum step size with proper anti-collision algorithms. By using special approaches, such writing calibration patterns, linearisation of position and careful backlash correction the absolute accuracy of the aperture size and position, can be improved beyond the standard afforded by the repeata…
Study of the recombination around the excitonic region of MBE ZnSe:Cl thin films
2008
The recombination processes around the excitonic region of undoped ZnSe and chlorine doped ZnSe thin films were studied by continuous-wave photoluminescence (cw-PL) and time-resolved photoluminescence (TRPL) spectroscopies. Samples with different chlorine concentration were obtained by varying the temperature of the Cl source. The evolution of the PL signal and its decay time were analyzed as a function of temperature. Activation energy (Ea) values associated to the quenching of the D0X and band-to-band emission were obtained from the temperature dependent cw-PL experiments. The activation energy was lower for the film with higher Cl content. The characteristic exponential decay time (TPL) …
Beam optics and magnet technology of the microtron in mainz
1981
Abstract A description is given of the beam transport system for injection into the first microtron of MAMI. Further, a special procedure to improve the field distribution of the dipole magnets is described in some detail and results are given.
Production and decay of charmed mesons at the Z resonance
1991
Abstract In a sample of 190 000 hadronic Z decays, three signals of charm production are observed: two from the exclusive decays D ° → K − π + and D ∗+ → D °π + → K − π + π + and one in the transverse-momentum distribution of soft hadrons relative to the nearest jet. The features of these signals are in good agreement with expectations based on the standard model and previous measurements of the branching fractions. The number of D ∗± → K ± π ± π ± per hadronic decay of the Z is measured to be (5.11±0.34) × 10 −3 , and the branching ratio B(D 0 → K − π + ) is (3.62 ± 0.34 ± 0.44)%. Charm hadronization has been studied. The average fraction of the beam energy carried by the D ∗ meson is foun…
High-resolution scattering experiments at the K130 cyclotron in Jyväskylä
2018
Abstract An experimental setup for nuclear reaction studies induced by light and heavy ions is described. It consists of a versatile Large Scattering Chamber equipped with two rotating tables for mounting detectors. A dedicated beam diagnostic system is used to monitor the energy spectrum of the beam on target. The system provides the necessary feedback for tuning of the K-130 cyclotron to reduce the energy spread of the accelerated beam by at least a factor of 3 down to about 0.3% of the nominal energy while maintaining beam currents around 20 pnA. At lower beam currents a 0.1% energy spread can be achieved. This improvement makes a significant impact on the scope of reaction studies possi…
Probing the limit of nuclear existence: Proton emission from 159Re
2006
WOS: 000240847400007
Decay of the high-spin isomer in 160Re: Changing single-particle structure beyond the proton drip line
2011
WOS: 000286708700015
Electromagnetic transition probabilities in 130Ce
1992
Abstract Lifetimes of excited nuclear states have been measured in 130Ce using the coincidence-plunger technique. The employed nuclear reaction was 98Mo(36S, 4n)130Ce at a beam energy of 150 MeV. The measurement has been performed at the NSF Daresbury using the ESSA 30 set-up. It was possible to determine lifetimes for the 4+ to 16+ states in 130Ce. The experimental B(E2) values could be well reproduced by calculations using the triaxial rotor model with β = 0.26 and γ = 21° as well as the rotation vibration model (β = 0.25).