Isotope production

N.P. Dikiy, A.N. Dovbnya, N.A. Skakun, V.L. Uvarov, M.A. Khazhmuradov, B.I. Shramenko, Use of accelerators in geology, medicine, isotopes production and atomic power energetic. Problems of Atomic Science and Technology (PAST), Nuclear Physics Investigation Series, 2001, No. 1, pp. 26-35. 

The HFBR at Brookhaven National Laboratory is a heavy water moderated and cooled reactor designed to provide an intense beam of neutrons to the experimental area. In addition using thimbles i oiitaincd within the vessel, it provides isotopic production, neutron activation analysis, ami muiemi irradiations. It began operation in 1965 at a power of 40 MW to be upgraded to 60 MW m 19S2. 

Figure 3. Wave vector diagram for the reaction X + HD + - XI+ + J where I and J may he H or D according to the isotopic product considered...

Figure 5. Ratio of isotopic product ions as a function of average reactant ion kinetic energy He + HD+ andNe + HD +...

Table lb. Recoil separations for isotope production or enrichment... 

The only respect in which the hot atom chemistry of organometallic compounds has so far been applied to other fields of study is in the area of isotope enrichment. Much of this has been done for isolation of radioactive nuclides from other radioactive species for the purpose of nuclear chemical study, or for the preparation of high specific activity radioactive tracers. Some examples of these applications have been given in Table II. The most serious difficulty with preparation of carrier-free tracers by this method is that of radiolysis of the target compound, which can be severe under conditions suited to commercial isotope production, so that the radiolysis products dilute the enriched isotopes. A balance can be struck in some cases, however, between high yield and high specific activity (19, 7J),... 

Mausner, L. F. Kolsky, K. L. Joshi, V. Sweet, M. P. Meinken, G. E. Srivastava, S. C. In Scandium-47 A replacement for Cu-67 in nuclear medicine therapy with beta/gamma emitters, Isotope Production and Applications in the 21st Century, Proceedings of the International Conference on Isotopes, Vancouver, BC, Canada, 1999 Stevenson, N. R., Ed. World Scientific Publishing Singapore, 1999. 

It is expected that due to the short residence time of Be and Cl in the atmosphere, 10Be and 36C1 measurements on ice cores will directly reveal isotope production variations. Due to dilution in the C02 exchanging system the atmospheric 14C/C-ratio shows a dampened response to 14C production rate variations. In contrast to the noble gas radioisotopes the size of the effective dilution reservoir - atmosphere plus parts of the ocean and biosphere - depends on the characteristic... 

Studies Based on Isotope Production in Meteorites and on the Lunar Surface... 

ISOTOPE PRODUCTION IN ATMOSPHERES DIFFERENT PATHWAYS ACCORDING TO GEOCHEMICAL PROPERTIES... 

T.J. Ruth, Accelerators available for isotope production, in M.J. Welch, C.S. Redvaniy (Eds.), Handbook of Radiopharmaceuticals—Radiochemistry and Applications, Wiley, Chichester, 2003, pp. 71-86. 

Irradiations. The irradiations are performed at the Isotope Production Facility (IPF) at the Los Alamos Meson Physics Facility (LAMPF) Target handling has been described elsewhere (7-9) Irradiation lengths vary from 2 to 29 days at a nominal beam intensity of 500 p-amps (at the IPF). Generally, the targets are located in irradiation positions (stringers) 2 or 3. 

Isotope Production Facility" in LAMPF Users Handbook, Los Alamos National Laboratory report MP-DO-l-UHB (Rev) 1980, 6B-7. 

In practice, the Szilard-Chalmers reaction has not been very successful for production of substantial quantities of any isotope although it often works well for tracer or low irradiation levels. When greater levels of neutron irradiation became feasible with development of nuclear reactors, it was found that both enrichment factors and product yields decreased as neutron exposures increased to the values required for significant isotope production. 

Isotopic enrichment in the molecular system can in principle be achieved by a two-step process, namely, the selective excitation of a specific isotopic species by monochromatic light and the removal of the specific isotopic product from other isotopic species by physical or chemical means. 

Figure 7.4 shows the reduction in sulfates and the corresponding growth of both the parent carbonates and the offspring methane with subbottom depth. The methane production is parallel but lower in isotope production than the carbonates. In Figure 7.4 the sulfur isotope (< 34S) content is defined in an identical manner to Equation 7.2 with the replacement of the fraction 13C/12C by 34S/32S in both the numerator and the denominator, using Canon Diablo meteoritic troilite as a standard. The < 34S value increases from 20-60%c before substantial biogenic methane is produced. 

Stone JO (2000) Air pressure and cosmogenic isotope production. J Geophys Res 105 23753-23759 Stone JOH, Evans JM, Fifield LK, Allan GL, Cresswell RG (1998) Cosmogenic chlorine-36 production in calcite by muons. Geochim Cosmochim Acta 63 433-454... 

It is interesting to note, however, that at higher energies heavy ions can produce comparable yields to protons and at much lower specific energy. The main reason is that thick-target techniques now become feasible for heavy ions as well. The consequence is that, microampere-for-microampere at 50 MeV/u, ZC projectiles should be the equivalent of 600 MeV protons for isotope production, and are possibly better for the most exotic products [HARM]. 

Raw material for the 4 Gd target was produced by spallation reactions in a tantalum metal target by 750-MeV protons at the Isotopes Production Facility at LAMPF. The details of the irradiation and the chemistries associated with separating the hafnium and lanthanide fractions have been reported previously.9 ... 

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