Search results for "IONIZATION"

Selective laser ionization of very neutron-rich cadmium isotopes: Decay properties of131Cd83and132Cd84

2000

A chemically selective laser ion source has been applied in a decay study of the very neutron-rich isotopes ${}^{131}\mathrm{Cd}$ and ${}^{132}\mathrm{Cd}$ at CERN/ISOLDE. For the ${\ensuremath{\beta}}^{\ensuremath{-}}$ decay of the $N=83$ nuclide ${}^{131}\mathrm{Cd}$ a surprisingly short half-life of $(68\ifmmode\pm\else\textpm\fi{}3)$ ms and a weak delayed-neutron branch of ${P}_{n}=(3.5\ifmmode\pm\else\textpm\fi{}1.0)%$ were observed. For the $N=84$ nuclide ${}^{132}\mathrm{Cd}$ a half-life of $(97\ifmmode\pm\else\textpm\fi{}10)$ ms and a ${P}_{n}$ value of $(60\ifmmode\pm\else\textpm\fi{}15)%$ were obtained. Schematic features of both decay schemes are developed. We find that our new d…

The effect of magnetic field strength on the time evolution of high energy bremsstrahlung radiation created by an electron cyclotron resonance ion so…

2009

Abstract An electron cyclotron resonance (ECR) ion source is one of the most used ion source types for high charge state heavy ion production. In ECR plasma the electrons are heated by radio frequency microwaves in order to provide ionization of neutral gases. As a consequence, ECR heating also generates very high electron energies (up to MeV region) which can produce a vast amount of bremsstrahlung radiation causing problems with radiation shielding and heating superconducting cryostat of an ECR ion source. To gain information about the time evolution of the electron energies in ECR plasma radial bremsstrahlung measurements were performed. JYFL 14 GHz ECR ion source was operated in pulsed …

SINGLET NEUTRINOS AS HOT DARK MATTER

1993

A model is presented that generates mass and magnetic moment matrices for singlet neutrinos radiatively at one-loop level. It allows the singlet neutrinos to account for the hot dark matter and the anomalous ionization of interstellar hydrogen.

β-decay studies of135–137Snusing selective resonance laser ionization techniques

2002

The decays of the very neutron rich Sn isotopes Sn135-137 were studied at CERN/ISOLDE using isotopic and isobaric selectivity achieved by the use of a resonance ionization laser ion source and mass spectroscopy, respectively. Neutron decay rates, gamma-ray singles, and gamma-gamma coincidence data were collected as a function of time. The half-life (T-1/2) and delayed neutron emission probability (P-n) values of 135 Sn were measured to be 530(20) ms and 21(3)%, respectively. For Sn-136, a T-1/2 of 250(30) ms was determined along with a P-n value of 30(5)%. For Sn-137, a T-1/2 of 190(60) ms and a P-n value of 58(15)% were deduced. Identification of low-energy transitions in Sb-135 was made p…

Astrophysics and spectroscopy with microcalorimeters on an electron beam ion trap

2003

The importance of the combination of electron beam ion trap (EBIT) spectroscopy with X-ray microcalorimeters in the field of astrophysics was discussed. X-ray astronomy involves heavily charged ion instruments , especially EBIT, to obtain improved quality atomic data. In this regard, the research program at the National Institute of Standards and Technology, which uses X-ray spectroscopic methods to study plasma and atomic physics, was also discussed.

Intense mass-separated beams of halogens and beta-delayed neutron emission from heavy bromine isotopes

1984

Improved production yields of short-lived halogens were obtained from a ThO2 target, irradiated with 600 MeV protons, in combination with a negative surface ionization source. Mass-separated samples were studied by decay spectroscopy. Production yields of radioactive isotopes of chlorine, bromine, iodine and astatine are presented. Half-lives and relative neutron emission probabilities were measured for the heavy bromine isotopes89−92Br. Normalizing to earlier publishedPn values for89Br, the results are:89Br (4.30±0.14s,P n =13.6±0.8%),90Br (1.92±0.06s,P n =24.8±1.5%),91Br (0.53 ±0.03 s,P n =30.1 ±2.1%), and92Br (0.31 ±0.02 s,P n =34.6±2.5%). Energy spectra ofβ-delayed neutrons were measure…

CMB anisotropies: cosmic confusion and polarization

2001

Abstract Some physical effects producing Cosmic Microwave Background (CMB) anisotropies are briefly described. The CMB angular power spectrum is calculated -in appropriate cases- with the essential aim of estimating and comparing the effects produced by reionization and gravitational waves; thus a problem of Cosmic Confusion is pointed out. Accurate measurements of the CMB polarization could solve this problem in future. Some comments about the PLANCK mission —ESA project for anisotropy detection— are given.

β−decay of the neutron-rich isotope215Pb

2013

This Brief Report reports on the first observation of the β--delayed γ decay of 215Pb, feeding states in 215Bi. The 215Pb beam was produced using resonant laser ionization and mass separated at the ISOLDE-CERN on-line mass separator. This ensured clean identification of the γ rays as belonging to the decay of 215Pb or its β-decay daughters. A half-life of 147(12) s was measured for the 215Pb β decay and a level scheme for the daughter nucleus 215Bi is proposed, resulting in an extended systematics of the excited states of the neutron-rich Bi isotopes.

2018

Abstract This article presents a pulsed narrowband injection-locked Titanium:Sapphire laser aimed for high-resolution in-jet resonance ionization spectroscopy at the SLOWRI/PALIS at RIKEN. The laser has been integrated into the PALIS laser laboratory enabling it to be utilized with the existing broadband Titanium:Sapphire and dye lasers. The seed efficiency has been evaluated to be close to unity over the master laser wavelength range ∼ 753 to 791 nm, and the slope efficiency, namely the ratio of the pump power to the output power, was determined to be ∼ 30 % at 780 nm. A two-step ionization scheme with 386.4016 nm first step and 286.731 nm second step into an autoionizing state was develop…

Resonance Ionization Laser Ion Source - Off-line tests at TRIUMF

2004

Resonance ionization laser ion sources (RILIS) developed into the most powerful tool for radioactive ion beam production at on-line facilities, as they provide a selective ionization process with inherent suppression of unwanted isobaric contaminations at the ion source. While typical tunable laser systems for these applications are based on dye lasers, we developed an all solid state laser system which consists of three pulsed titanium:sapphire (ti:sa) lasers pumped by a single high repetition rate Nd:YAG laser. Each ti:sa laser provides up to 2.5 W average output power at 12 kHz repetition rate in the wavelength region of 700-950 nm with optional frequency doubling in BBO crystals. This l…