Search results for "RADIOCHEMISTRY"

Radiochemical Studies of Complex Nuclear Reactions

1995

Simulations of the stopping efficiencies of fission ion guides

2017

With the Ion Guide Isotope Separator On-Line (IGISOL) facility, located at the University of Jyväskylä, products of nuclear reactions are separated by mass. The high resolving power of the JYFLTRAP Penning trap, with full separation of individual nuclides, capacitates the study of nuclides far from the line of stability. For the production of neutron-rich medium-heavy nuclides, fissioning of actinides is a feasible reaction. This can be achieved with protons from an in-house accelerator or, alternatively, with neutrons through the addition of a newly developed Be(p,xn)-converter. The hereby-obtained fission products are used in nuclear data measurements, for example fission yields, nuclear …

A study of a helium-jet ion guide for an on-line isotope separator

1981

Abstract A new method based on helium-jet techniques permits primary recoil ions, produced in radioactive decay or in nuclear reactions to be run directly through a mass separator. Results obtained with a 227 Ac source promise qualities complementary with those obtained with conventional ion sources and indicate an overall efficiency of the order of 10%. Preliminary results with 20 Na recoils from the 20 Ne(p,n)-reaction indicate that most of the ionic species transported out from the target chamber are negatively charged.

The Szilard–Chalmers effect in macrocyclic ligands to increase the specific activity of reactor-produced radiolanthanides: Experiments and explanatio…

2012

Abstract Successful utilization of medical isotopes in the radiolabeling reactions to a significant degree depends on the technically achievable specific activity. In this respect, the Szilard-Chalmers effect is considered in detail as a radiochemical tool to increase the specific activity of radionuclides produced by direct nuclear reactions. In the present study, a physico-chemical model is described utilizing the specific aspects of thermodynamically and kinetically stabilised metal-ligand complexes. The approach is applied as a proofof- principle study to increase the specific activity of 166Ho, produced via the (n, γ) nuclear reaction. As a target material, 165Ho-DOTA is used. In this …

Study of Proton and 3He Induced Reactions on 235U at Low Energies

2014

Abstract Highly enriched 235 U targets were irradiated with 6.5 − 16.1 MeV protons and 20.4 − 42.0 MeV 3 He ions. The irradiated targets were measured with γ and α spectrometric methods to identify and quantify the produced reaction products. After primary activity measurements the targets were dissolved, and interesting Pu and Np reaction products were chemically separated from the target material, and measured for activity again. From the activity results it was possible to calculate the reaction cross sections for differently produced nuclides. The data obtained from the experiment resulted in earlier unknown excitation functions on proton and 3 He induced nuclear reactions on 235 U.

Attempts to chemically investigate element 112

2006

Summary Two experiments aiming at the chemical investigation of element 112 produced in the heavy ion induced nuclear fusion reaction of 48Ca with 238U were performed at the Gesellschaft für Schwerionenforschung (GSI), Darmstadt, Germany. Both experiments were designed to determine the adsorption enthalpy of element 112 on a gold surface using a thermochromatography setup. The temperature range covered in the thermochromatography experiments allowed the adsorption of Hg at about 35 °C and of Rn at about -180 °C. Reports from the Flerov Laboratory for Nuclear Reactions (FLNR), Dubna, Russia claim production of a 5-min spontaneous fission (SF) activity assigned to 283112 for the 238U(48Ca,3n)…

Activation cross-sections for some 14·8 MeV neutron-induced nuclear reactions on caesium: Isomer ratios of 134Cs, 133Xe and 130I

1970

Abstract Absolute cross-sections for 14·8 MeV neutron-induced reactions on 133Cs were determined using the activation technique. The results, with maximum errors of 15 per cent, are: ρ(n,γ)=7·1 mb (ρ(n,γ) 134m Cs =1·82 mb , ρ(n,γ) 134g Cs =5·3 mb ; ρ(n,2n) 132 Cs =1620 mb ; ρ(n,p)=10·5 mb (ρ(n,p) 133m Xe =4·8 mb , ρ(n,p) 133g Xe =5·7 mb ; ρ(n,α)=1·14 mb (ρ(n,α) 130m I =0·54 mb , ρ(n,α) 130g I =0·6 mb ; ρ(n, 3 He ) 131 I =3·2 μ barn ; ρ(n,2p) 132 I ⩽12 μ barn . At this particle energy direct interaction processes also contribute. The isomer cross-section ratios σ m σ g for 134Cs, 133Xe and 130I are 0·34±0·08, 0·85±0·15 and 0·91±0·2 respectively. A reinvestigation of the alleged 127I (n, 3n)1…

Production of plutonium tracers in 237Np nuclear reactions with 3He-ions in the energy range from 26 to 60 MeV

1998

Cross-sections for the reaction Np-237 + He-3 --> Pu-236,Pu-237,Pu-238 at He-3 bombarding energies from 26 to 60 MeV were measured. Thick-target yields, based on the measured and previously known cross-sections were constructed. The results are discussed and compared with Ether reactions leading to the formation of the same final nuclei. (C) 1998 Elsevier Science S.A.

<title>Study of color centers in optical fibers to be used for ITER plasma diagnostics</title>

2007

ABSTRACT The paper presents a comparative study, by off-line measurements of the irradiation induced optical attenuation in several large diameter (600 µm) optical fibers subjected to gamma-rays and neutron irradiation. The optical fiber samples fall into two categories: optical fibers with an enhanced UV transmission (high OH content core) and solarization resistant optical fibers. The irradiation conditions were as follows: a) gamma irradiation at a 60 Co source, with a dose rate of 0.33 kGy/h +/- 5%, up to the maximum total irradiation dose of 313 kGy; b) neutron irradiation (mean energy 5.2 MeV) using a deuteron beam (13 MeV) and a thick beryllium target, for a total fluence of 6x10 12 …

Oxygen diffusion in tissues supplied by capillaries.

1968

(1968). Oxygen Diffusion in Tissues Supplied by Capillaries. Scandinavian Journal of Clinical and Laboratory Investigation: Vol. 21, No. sup102, pp. II-B-II-B.