Search results for "Lung"

Investigation of the ββ decay of 116Cd into excited states of 116Sn

1994

Abstract The double-beta decay of 116Cd into excited states of 116Sn is experimentally and theoretically investigated. From an inclusive experiment, using an external source of isotopically enriched Cd, new most stringent limits for the allowed and non-standard-model decays into excited states are derived. It is further investigated whether the bremsstrahlung emitted by the ββ electrons can be used to derive information on the ground-state decay. For the two-neutrino-decay mode a calculation, using the quasiparticle random-phase approximation, shows that the disadvantage in phase space, in comparison to the ground-state decay, is partially compensated through the nuclear-matrix element. Exp…

Future Experimental Developments for Few-Body Physics at Mainz

1986

The racetrack microtron MAMI B [1] now under construction at Mainz will provide a high-intensity electron beam with energies up to 840 MeV. The 100% duty factor, high-quality beam is considered to be ideal for the investigation of the nucleus in the medium energy region. Coincidence experiments with the detection of the scattered electron and the hadronic reaction products will become possible in a wide kinematical range yielding the information about the response of the nucleus to the transferred energy and momentum. By the method of bremsstrahlung tagging intense secondary photon beams with high monochromacity and well known fluxes will be available for photonuclear research work. Further…

Measurement of photon showers in lead produced by electrons of 150 MeV

1976

Abstract The photon energy spectra induced by 150 MeV electrons in lead were measured in the energy range from 40 MeV up to the primary electron energy. The target thickness was varied between 0.1 and 2.5 radiation lengths X 0 . The photons were analyzed by use of a technique based on deuteron photodisintegration. Differential and integral shower spectra are presented and compared with Monte Carlo calculations of Nagel and Messel et al., both interpolated to our primary energy of 150 MeV. The measured spectra show good agreement with these Monte Carlo calculations for the thickest target of 2.5 X 0 and with calculated bremsstrahlung spectra for the thinnest target of 0.1 X 0 . Considerable …

Langevin approach to collisional bremsstrahlung in a magnetic field

1994

A new plunger device to measure lifetimes of unbound states in tagged exotic nuclei

2012

A new plunger device has been designed and is being built at the University of Manchester to measure lifetimes of unbound states in exotic nuclei approaching the proton drip-line. The device is designed to work in both vacuum and gas environments and will be used in conjunction with the gas filled separator RITU and the vacuum-mode separator MARA at the University of Jyvaskyla, Finland. This will enable the accurate measurement of excited state lifetimes identified via isomer and charged-particle tagging. The plunger will be used to address many key facets of nuclear structure physics with particular emphasis on the effect of deformation on proton emission rates.

Development of a new Recoil Distance Technique using Coulomb Excitation in Inverse Kinematics

2009

We report on an experiment using Coulomb excitation in inverse kinematics in combination with the plunger technique for measuring lifetimes of excited states of the projectiles. Aside from the investigation of E(5) features in 128Xe, the aim was to explore the special features of such experiments which are also suited to be used with radioactive beams. The measurement was performed at the JYFL with the Koln coincidence plunger device and the JUROGAM spectrometer using a 128Xe beam impinging on a natFe target at a beam energy of 525 MeV. Recoils were detected by means of 32 solar cells placed at extreme forward angles. Particle‐gated γ‐singles and γγ‐coincidences were measured at different t…

Heavy isotopes of actinium: 229Ac, 230Ac, 231Ac and 232Ac

1973

Abstract By irradiation of 232Th with 150-MeV bremsstrahlung and with 14-MeV neutrons, three new neutron-rich isotopes of actinium, 230Ac, 231Ac and 232Ac, were produced and identified and the previously reported isotope, 229Ac, was confirmed. The actinium isotopes were chemically isolated by a fast procedure based on elution with α-hydroxyisobutyric acid from cation exchange resins. For 229Ac, a half-life of 62·7 ± 0·5 min and a β-ray energy of 1·14 ± 0·15 MeV were found; 35 γ-rays were observed, the strongest ones with the following energies and relative intensities: 135·3(34), 146·4(35), 164·6(100), 252·2(24), 261·9(39), 317·0(23), 539·9(20), 569·1(91), and 605·2 keV(23). For 230Ac, a ha…

Plunger Lifetime Measurements in 102Pd

2006

Recently, an intense experimental effort has been devoted to the search of empirical proofs of critical‐point symmetries in nuclear structure. These symmetries describe shape‐phase transitions and provide parameter‐free predictions (up to over‐all scale factors) for excitation spectra and B(E2) values. This contribution reports on recent plunger‐lifetime measurements ON 102Pd carried out at LNL, Legnaro, with the Cologne plunger apparatus coupled to the GASP spectrometer and using the 92Zr(13C,3n)102Pd reaction at 48 MeV. According to the results of our measurements, 102Pd is so far the best known paradigm of the E(5) critical‐point symmetry.

Photoproduction of $ \pi^{0}$ -pairs off protons and off neutrons

2015

Total cross sections, angular distributions, and invariant-mass distributions have been measured for the photoproduction of $\pi^0\pi^0$ pairs off free protons and off nucleons bound in the deuteron. The experiments were performed at the MAMI accelerator facility in Mainz using the Glasgow photon tagging spectrometer and the Crystal Ball/TAPS detector. The accelerator delivered electron beams of 1508 and 1557~MeV, which produced bremsstrahlung in thin radiator foils. The tagged photon beam covered energies up to 1400~MeV. The data from the free proton target are in good agreement with previous measurements and were only used to test the analysis procedures. The results for differential cros…

On numerical broadening of particle-size spectra: a condensational growth study using PyMPDATA 1.0

2022

This work discusses the numerical aspects of representing the condensational growth of particles in models of aerosol systems such as atmospheric clouds. It focuses on the Eulerian modelling approach, in which fixed-bin discretisation is used for the probability density function describing the particle-size spectrum. Numerical diffusion is inherent to the employment of the fixed-bin discretisation for solving the arising transport problem (advection equation describing size spectrum evolution). The focus of this work is on a technique for reducing the numerical diffusion in solutions based on the upwind scheme: the multidimensional positive definite advection transport algorithm (MPDATA). S…