W. Hajdas

Search for cold-fusion events

Abstract In a recent electrochemical investigation M. Fleischmann and S. Pons [1] found some excess heat, which — according to the authors — was due to the cold fusion of deuterium nuclei. Using a very similar experimental arrangement we looked for the characteristic neutrons and gamma rays from the dd fusion reaction. None were found. In addition, LaNi5, a substance which is known to absorb a very large amount of hydrogen, was loaded with deuterium gas. Again no nuclear fusion processes could be observed.

Cross section and analyzing power A y in the breakup reaction H 2 ( p →, pp ) n at 65 MeV: Collinearity configurations

Kinematically complete breakup cross section and proton analyzing power data for four different collinearity configurations (neutron at rest in the c.m. system) have been measured in the reaction [sup 2]H([ital [rvec p]],[ital pp])[ital n] at [ital E][sub [ital p]][sup lab]=65 MeV. The experimental data are compared with rigorous solutions of the Faddeev equations using the Argonne AV14, Bonn B, Nijmegen, and Paris potentials. While the overall agreement is quite good there exist distinct discrepancies between theoretical and experimental cross section and analyzing power data in some regions of phase space.

Analyzing power in n+d elastic scattering at 67 MeV

The analyzing power Ay of 2H(n, n)2H elastic scattering at En = 67 MeV has been measured in the angular range 30° < θ c.m. < 165°. The data are in good agreement with the results of our rigorous three-nucleon calculations employing the PARIS and the BONN B potential.

Effects of the Tucson-Melbourne three-nucleon force in the proton-deuteron breakup process at Ep = 65 MeV

Abstract We present the calculated cross sections and vector analyzing powers using the Bonn B nucleon-nucleon potential and the Tucson-Melbourne three-nucleon force ( 3NF ) for six collinearity and quasi-free scattering breakup configurations. These calculations are compared to the results of the recent kinematically complete pd experiments at E p = 65 MeV. The Tucson-Melbourne 3NF , adjusted together with the Bonn B potential to reproduce the triton binding energy, leads to small effects both in cross sections and analyzing powers in all six studied configurations.

Analyzing power of the 2H(n, np)n breakup reaction at 67 MeV in selected kinematical configurations

Abstract The angular distribution of the analyzing power A y for the 2 H( n , np)n breakup reaction at 67 MeV was measured in two kinematical regions: np quasi-free scattering and np final-state interaction. The results are compared with rigorous three-nucleon calculations using the Paris potential and allowing for charge dependence in the 1 S 0 state. According to the actual experimental conditions energy averaging was simulated in the theoretical calculations. In both configurations agreement between experimental and calculated values is found.

Differential cross section for elastic n+d scattering and n+d break-up quasi free-scattering at 67 MeV

Abstract The differential cross sections for the n+d elastic scattering and for the 2 H(n,np)n break-up reaction in the np quasi-free scattering configuration was measured at 67 MeV. The experimental data are compared with results of the calculations based on a rigorous solution of the three-nucleon Faddeev equations using meson-exchange potentials. Good agreement is found between experiment and theory for the n+d elastic-scattering cross section while in the case of np quasi-free scattering the theoretical predictions overestimate the data at neutron angles larger than 40° by about 30%.

Cross Section and Analyzing Power Ay in the Proton Induced Deuteron Breakup Reaction at 65 MeV

One of the basic questions in nuclear physics deals with the nature of the two-nucleon (2N) interaction. While QCD can not yet be solved in the nonperturbative regime required for an answer, meson theory has achieved some maturity and provides realistic 2N-forces, which are able to describe very well the great amount of 2N data. It is now of interest to see whether those forces can also be used in systems, where more than two nucleons interact. The simplest one, the three-nucleon system (3N) has always been considered as an ideal testing ground for our understanding of the 2N-interactions. Assuming 2N forces only, the Hamiltonian for the 3N system is fixed. Does it describe the experimental 3N observables? Is it necessary to introduce additionally genuine 3N forces in the dynamics of the 3N system? Now, with the advent of supercomputers, the 3N Faddeev equations can be solved in a numerically rigorous way for any local or nonlocal 2N interaction [1,2]. Therefore, the meson-exchange dynamics in nucleon-nucleon forces can be tested reliably in the 3N system by comparing the calculations with precise experimental data. The aim of the reported experiment is to provide accurate continuum 3N observables in those kinematical regions where, according to model calculations, the 3N force effects are enhanced and, simultaneously, the sensitivity to details of the 2N potential is small [3].

Cross section and analyzing power [ital A][sub [ital y]] in the breakup reaction [sup 2]H([ital [rvec p]],[ital pp])[ital n] at 65 MeV: Collinearity configurations

Kinematically complete breakup cross section and proton analyzing power data for four different collinearity configurations (neutron at rest in the c.m. system) have been measured in the reaction [sup 2]H([ital [rvec p]],[ital pp])[ital n] at [ital E][sub [ital p]][sup lab]=65 MeV. The experimental data are compared with rigorous solutions of the Faddeev equations using the Argonne AV14, Bonn B, Nijmegen, and Paris potentials. While the overall agreement is quite good there exist distinct discrepancies between theoretical and experimental cross section and analyzing power data in some regions of phase space.

Cross section and analyzing powerAyin the breakup reactionH2(p→,pp)nat 65 MeV: Collinearity configurations

Kinematically complete breakup cross section and proton analyzing power data for four different collinearity configurations (neutron at rest in the c.m. system) have been measured in the reaction [sup 2]H([ital [rvec p]],[ital pp])[ital n] at [ital E][sub [ital p]][sup lab]=65 MeV. The experimental data are compared with rigorous solutions of the Faddeev equations using the Argonne AV14, Bonn B, Nijmegen, and Paris potentials. While the overall agreement is quite good there exist distinct discrepancies between theoretical and experimental cross section and analyzing power data in some regions of phase space.

Absolute calibration of the transverse analyzing power in proton-carbon elastic scattering at 50. 24 MeV

To provide an accurately calibrated polarization analyzer, the analyzing power for elastic scattering of protons from natural carbon at {ital E}{sub lab}=50.24 MeV and {theta}{sub lab}=50.0{degree} was measured by scattering protons of very high and precisely known polarization (0.9965{plus minus}0.0007) from a graphite target. The result of the calibration is {ital A}=0.9277{plus minus}0.0036, where the error is the quadratic sum of the statistical error {plus minus}0.0033 and systematic uncertainties which total {plus minus}0.0016.