Search results for "PLASMA"
showing 10 items of 4043 documents
Hybrid simulation of electron cyclotron resonance heating
2008
Electron Cyclotron Resonance (ECR) heating is a fundamentally important aspect in understanding the physics of Electron Cyclotron Resonance Ion Sources (ECRIS). Absorption of the radio frequency (RF) microwave power by electron heating in the resonance zone depends on many parameters including frequency and electric field strength of the microwave, magnetic field structure and electron and ion density profiles. ECR absorption has been studied in the past by e.g. modelling electric field behaviour in the resonance zone and its near proximity. This paper introduces a new ECR heating code that implements damping of the microwave power in the vicinity of the resonance zone, utilizes electron de…
Equation of state of strongly interacting matter: spectra for thermal particles and intensity correlation of thermal photons
2010
We find that an equation of state for hot hadronic matter consisting of all baryons having $M < 2$ GeV and all mesons having $M < 1.5$ GeV, along with Hagedorn resonances in thermal and chemical equilibrium, matches rather smoothly with lattice equation of state (p4 action, ${N_��}=8$) for T up to $\approx 200$ MeV, when corrected for the finite volume of hadrons. Next we construct two equations of state for strongly interacting matter; one, HHL, in which the above is matched to the lattice equation of state at $T=165$ MeV and the other, HHB, where we match it to a bag model equation of state with critical temperature $T_c=165$ MeV. We compare particle spectra, thermal photon spectra …
NUCLEAR-STRUCTURE EFFECTS ON DOUBLE BETA DECAYS TO 0+ STATES IN 76Ge
2011
Neutrinoless double beta (0νββ) decay of 76 Ge to the ground state and first excited 0+ state in 76 Se is discussed in terms of the associated nuclear matrix elements. The effects arizing from the size of the single-particle model space and the occupancies of the individual orbits are discussed in the framework of the (higher) quasiparticle random-phase approximation with effective, G -matrix-derived nuclear forces. It is found that the orbital occupancies play a role for the size of the nuclear matrix element. Contrary to the ground-state transition the transition to the first excited 0+ state does not depend sensitively on the size of the model space.
Deconvolution of the spectral line profiles for the plasma temperature estimation
2010
Abstract The Hg 253.7 nm spectral line profiles, emitted from the mercury–argon high-frequency electrodeless discharge lamps (HFEDL) have been measured by means of a high-resolution scanning Fabry–Perrot interferometer at the mercury cold spot temperature value at 20 °C, different discharge current and buffer gas values. The deconvolution procedure by means of the Tikhonov's regularization method was performed to obtain the real spectral line shape. The influence of the instrumental function and absorption, real width of the Hg 253.7 nm resonance line and temperature of the radiating atoms are obtained. The results were compared with the results of the nonlinear multiparameter mathematical …
The first cooled beams from JYFL ion cooler and trap project
2002
Abstract A ion manipulation scheme employing a linear radiofrequency quadrupole and a Penning trap is described. It provides means to improve emittance, cool, bunch and mass-purify the existing ion beams from an Ion Guide Isotope Separator while preserving its fast operation. The ion beam cooler is operational and capable to cool ion beam down to eV regime in few ms with at least 60 percent transmission.
Charge-state dynamics of 1.4- and 11-MeV/u uranium ions penetrating H2 and He gas targets
2018
Abstract Theoretical description and interpretation are presented of the recent experimental data on stripping of fast 238U ions, penetrating H2 and He gaseous targets: obtained in GSI, Darmstadt, Germany at 1.4 MeV/u with a H2 stripper, and in RIKEN, Saitama, Japan at 11 MeV/u with H2 and He strippers. Electron-loss and capture cross sections for uranium ions, interacting with H2 and He targets are calculated and used as input data in the BREIT code to obtain dynamic characteristics of uranium-ion beams: non-equilibrium and equilibrium charge-state fractions, mean and equilibrium charges, and equilibrium thicknesses. Special attention is paid for the calculation of the dynamic characterist…
A highly selective laser ion source for bunched, low emittance beam release
2004
A novel type of resonance ionization laser ion source (RILIS) is under development, which combines the advantages of laser ionization with those of a source-implemented ion trap. This laser ion source trap (LIST) system, based on a gas-filled linear radio-frequency quadrupole ion trap, decouples the evaporation and ionization process by introduction of a primary surface ion repeller. Apart from significantly enhancing the selectivity in radioactive ion beam production, optimum control on the temporal pulse structure and the emittance of the generated laser ion bunch is obtained. A variety of operational modes from quasi-dc to microseconds-bunched ion beams with variable repetition rate can …
Beam phase measurement system for the K130 cyclotron in Jyväskylä
1993
Abstract A phase measurement system for Jyvaskyla new K = 130 heavy ion cyclotron has been designed and realized. The phase measurement is done using a set of capacitive probes to detect phase information from the internal ion beam. This data is vital for tuning purposes to obtain an isochronous magnetic field and to maximize the ion beam intensity.
High-resolution laser resonance ionization spectroscopy of $^{143-147}$Pm
2020
The European physical journal / A 56(2), 69 (2020). doi:10.1140/epja/s10050-020-00061-8
Highly deformed band inAg105
1995
The isotope Ag-105 has been studied using 169.5 MeV Cl-37 ions impinging on Ge-76. The Nordball Ge array detected the gamma rays and a 4 pi charged particle detector system detected emitted light charged particles. A very deformed band has been established using Doppler shift attenuation methods. The analysis is based on the gamma gamma coincidences and the angular dependence of the four rings of Ge detectors in Nordball. The deformation of the band is deduced to be beta(2)=0.37(-0.02)(+0.03).