Search results for "Recoil"

Primary-residue production cross sections and kinetic energies in 1AGeV 208Pb on deuteron reactions

2002

Abstract The production cross sections and the kinematical properties of primary residual nuclei have been studied in the reaction 208 Pb(1  A  GeV)+d. Isotopic distributions were measured for all elements from titanium ( Z =22) to lead ( Z =82). The measured kinematical properties of the residues were also used to disentangle the relevant reaction mechanisms, spallation–evaporation and spallation–fission. The fragment separator FRS at GSI, Darmstadt, was used to separate and identify the reaction products. The measured quantities are important for the design and planning of future radioactive-beam facilities and accelerator-driven systems. The measured data of the present work are comprehe…

Ca48+Bk249Fusion Reaction Leading to ElementZ=117: Long-Livedα-DecayingDb270and Discovery ofLr266

2014

The superheavy element with atomic number Z=117 was produced as an evaporation residue in the 48Ca+249Bk fusion reaction at the gas-filled recoil separator TASCA at GSI Darmstadt, Germany. The radioactive decay of evaporation residues and their α-decay products was studied using a detection setup that allowed measuring decays of single atomic nuclei with half-lives between sub-μs and a few days. Two decay chains comprising seven α decays and a spontaneous fission each were identified and are assigned to the isotope 294-117 and its decay products. A hitherto unknown α-decay branch in 270Db (Z=105) was observed, which populated the new isotope 266Lr (Z=103). The identification of the long-liv…

Half-lives andP n values of delayed-neutron precursors in the mass chains 85?87, 92, 135, 136 and 145

1978

Further results are presented on half-lives and neutron emission probabilities (P n ) of short-lived delayed-neutron precursors in the mass chains 85–87, 92, 135, 136 and 145 obtained with the recoil focussing parabola-type mass separator for unslowed fission products LOHENGRIN installed at the Grenoble high-flux reactor. A newP n -value of (44±14)% is given for the (0.73±0.06)s87As; theP n -values of seven precursor nuclides have been redetermined: (1.9±0.1)s85As with (22±8)%, 0.9s86As with (10.5±2.2)%, (0.35±0.04)s92Br with (21±8)%, (1.6±0.15)s135Sb with (14±1)%, (0.9±0.1)s136Sb with (19±9)%, (17.5±0.2)s136Te with (2.0±1.0)% and 0.6s145Cs with (12.5±3.0)%. The results are compared with th…

Microsecond isomers in 187Tl and 188Pb

2000

Lifetime measurements of states in nuclei with A=187 and 188 have been performed, using reactions between 155Gd and 36Ar and following the transport of evaporation residues to the focal plane of a gas-filled recoil separator. In a separate experiment using the 159Tb(32S, 4n) reaction the γ-decay of isomeric levels in 187Tl has been studied using delayed γ-γ coincidence measurements. From observation of their subsequent γ decay, the mean lifetimes were measured to be 1000 ± 55 ns and 1600 ± 100 ns. Although it was not possible to characterize the isomers completely, they are proposed as candidates for one-proton, two-neutron excitations. In the course of this study, the decay of an isomer in…

Probing shapes of very neutron deficientZ≈82 nuclei using the recoil-decay tagging method

1997

The JYFL gas-filled recoil separator, RITU, combined with efficient Ge-detector arrays has been employed in in-beam γ-ray studies of very neutron-deficient nuclei close to theZ=82 shell. Gamma-rays from nuclei produced at the few μb cross-section level have been detected.

Measurement of the neutron electric form factor

2003

Abstract The neutron electric form factor GE,n has been measured at three different four-momentum transfer in a D(|e|→, e′|e|→)p experiment. Neutronwere detected in a recoil 0 polarimeter, using a spin precession method. We present the experiment and the status of data analysis.

Investigation of a gas-catcher/ion guide system using alpha-decay recoil products

2002

Abstract 219Rn recoils from the alpha decay of 223Ra have been used to study the efficiency and delay time distributions of a gas-catcher/ion guide system. Ions with charge states up to +4 were coming out of the gas cell. Combining efficiency and delay time measurements, ion survival times in plasma free conditions can be deduced.

T- and P-asymmetries in the (γ, π−) reaction on 13C and 15N

1995

Abstract A simultaneous theoretical analysis of the polarization observables for negative pion photoproduction off the 13 C and 15 N nuclei is performed. A sensitivity of the target and recoil asymmetries to different ingredients of the theory (the Fermi motion, the final state interaction and the nuclear model input) is investigated. The importance of the high (2 hω ) configurations in the nuclea ground states is shown.

Recoil isomer tagging in the proton-rich odd-oddN=77isotones, 65142Tband 67144Ho

2001

Spin Physics with Photons — Technical Highlights and Spin-Offs

2016

The spin, as a fundamental property of a particle, has been a main object of investigation in particle and nuclear physics research in recent decades. For complete spin investigation, one requires a polarized target in addition to polarized beams and a recoil polarimeter. The advent of advanced beam and large acceptance detector technologies has driven the development of highly polarized, full angular acceptance targets. The Crystal Ball detector with its unique capability to cope with multi photon final states is used in Mainz at the A2 real photon facility in combination with a frozen spin polarized target. Technical highlights from the development of thin superconducting magnets to prov…