Kjell Aleklett

The Peak and Decline of World Oil and Gas Production

Extrapolating the discovery trend of the past to determine future discovery and production should be straightforward, and the size distribution of the fields should be evident. But the atrociously unreliable nature of public data has given much latitude when it comes to interpreting the status of depletion and the impact of economic and political factors on production. This has allowed two conflicting views of the subject to develop. The first is what may be called the Natural Science Approach, which observes the factors controlling oil accumulation in Nature and applies immutable physical laws to the process of depletion. The second is what may be called the Flat-Earth Approach, in which the resource is deemed to be virtually limitless, with extraction being treated as if it were controlled only by economic, political and technological factors. This paper will endeavor to present the evidence for the Natural Science Approach, addressing the geological constraints; the technical basis of reserve estimatio...

Search for the production of element 112 in the 48Ca+238U reaction

Author(s): Loveland, Walter; Gregorich, Ken; Patin, Joshua B.; Peterson, D.; Rouki, C.; Zielinski, Peter M.; Aleklett, K.

Development journey and outlook of Chinese giant oilfields

Over 70% of China’s domestic oil production is obtained from nine giant oilfields. Understanding the behaviour of these fields is essential to both domestic oil production and future Chinese oil im ...

Problem-Based Distance Learning of Energy Issues via Computer Network.

Problem‐based learning (PBL) modified for distance education (PBDiL = Problem‐Based Distance Learning) has been used for teaching energy issues at Uppsala University, Sweden. Collaborative learning in groups of seven to eight students was enabled by computer communication and enhanced the use of Internet. Two different teaching methods have been tried and are compared, both being influenced by methods used in conventional face‐to‐face PBL. The problem presentation was entirely built on pictures, and examination through student reports was successful. A student remark, ‘I study on my own but yet not alone’ shows the importance of social contact.

Cross-section limits for the 208Pb(86Kr, n) 293118 reaction

Abstract.In April-May, 2001, the previously reported experiment to synthesize element 118 using the 208Pb(86Kr,n)293118 reaction was repeated. No events corresponding to the synthesis of element 118 were observed with a total beam dose of 2.6 x 1018 ions. The simple upper-limit cross-sections (1 event) were 0.9 and 0.6 pb for evaporation residue magnetic rigidities of 2.00 Tm and 2.12 Tm, respectively. A more detailed cross-section calculation, accounting for an assumed narrow excitation function, the energy loss of the beam in traversing the target and the uncertainty in the magnetic rigidity of the Z = 118 recoils is also presented. Re-analysis of the primary data files from the 1999 experiment showed the reported element 118 events are not in the original data. The current results put constraints on the production cross-section for synthesis of very heavy nuclei in cold-fusion reactions.

Total β-decay energies and masses of short-lived isotopes of zinc, gallium, germanium and arsenic

Abstract Experimental total β-decay energies for short-lived isotopes of zinc, gallium, germanium and arsenic are presented. The sources were produced as mass-separated fission products at the OSIRIS on-line separator at Studsvik. By applying β-γ coincidence methods, Q β values were determined for 75–78 Zn, 76–79 Ga, 79, 80 Ge and 80, 81, 83 As. For these nuclei to the shell N = 50 and in the vicinity of the r-process “seed”, the atomic mass excess could be derived, allowing the comparison of masses of very neutron-rich unstable nuclei with predictions from mass formulae.

Total β-decay energies and masses of tin, antimony and tellurium isotopes in the vicinity of 13250Sn82

Abstract Experimental β-decay energies for short-lived isotopes of tin, antimony and tellurium are presented. Mass-separated sources were produced at the on-line isotope separator OSIRIS. By applying β-γ coincidence methods, total β-decay energies have been determined for the following nuclides: 127−131 Sn, 128, 130, 131, 134 Sb and 134, 135 Te. The atomic mass excess has been derived for these nuclei, and comparisons are made with mass formula predictions.

Production of intermediate mass fragments in ultrarelativistic nuclear collisions

Cross sections for formation of intermediate mass (A < 50) fragments in the collision of 60 and 200 A GeV16O with 238U have been measured. Limiting fragmentation behavior is observed. The thresholds for multifragmentation (Eprojin A GeV) are apparently lower in nucleus-nucleus collisions as compared to p-nucleus collisions, consistent with models in which multifragmentation is due to a mechanical instability of nuclear matter.

Gold target fragmentation by 800 GeV protons

Abstract Target fragmentation formation cross sections, angular distributions, and range spectra were measured for the interaction of 800 GeV protons with 197 Au. From the measured formation cross sections, isobaric yields were deduced. The range distributions were converted to energy spectra. The angular distributions are sideward peaked for the fission/deep spallation products with the maxima in the distributions occurring at 30°–60°. The angular distributions and energy spectra are consistent with previous measurements of the interactions of energetic protons with gold. Within experimental uncertainties, the mass-yield distribution from the interaction of 800 GeV protons with gold is the same as from the interaction of 11.5 GeV protons with gold. The microcanonical model for statistical decay of very highly excited nuclei reproduces the general trend of the measured isobaric yields from the interaction of 800 GeV protons with 197 Au although the calculation predicts more structure in the yields than is observed.

Heavy-residue spectra in the interaction of 85A MeV 12C with 197Au

Abstract We have measured the heavy-residue differential range distributions in the interaction of 85 MeV/nucleon 12 C with 197 Au. The range distributions were converted to energy spectra using known range-energy relationships. The mean residue energies range from 15 keV/nucleon ( A = 189) to 314 keV/nucleon ( A = 131). Longitudinal momenta of the heavy residues have been deduced. The mean spectral energies and the shapes of the residue spectra are shown to be in agreement with the predictions of the VUU model.