Irradiation with deuterons

Technetium (Tc, [Kr]4 /65.vl), name and symbol after the Greek Tsxrmos (tech-nikos, artificial). Detected in Italy (1937) by Carlo Perrier and Emilio Segre in a sample of Mo which had been irradiated with deuterons at the E.O. Lawrence cyclotron in California. It was the first artificially produced element. 

Tritium and He are obtained by the reactions d(d, p)t and d(d, n) He, respectively, if solid D2O is irradiated with deuterons. However, tritium is produced with much higher yield by irradiation of Li with neutrons (cTn, = 940 b) ... 

By irradiation with deuterons, one proton is introduced into the nucleus and (dn), or (d, 2n) reactions lead to the production of elements with Z - - 1, for instance... 

Fig. 2. Examination of sintered spheres. A pair of sintered spheres is first imbedded in a matrix and then sectioned. (A) The exposed surface is irradiated with deuterons. (B) The specimen is then covered with a photographic film and the darkening of the film can be taken as an indication of the location of activity.

The sources most commonly used so far consisted of sintered disks containing about 100 mg ZnO enriched with 90% Zn. The disks were irradiated with 12 MeV deuterons or 30 MeV He particles, to yield the 78 h activity of Ga, and then annealed by heating in oxygen to 700-1,000 K for about 12 h and cooling down slowly (about 50 K h ) to room temperature. A Nal scintillation counter, 2-3 mm thick, is suitable for the detection of the 93 keV y-rays. Because of the relatively high transition energy, both source and absorber are generally kept at liquid helium temperature. 

The two Mossbauer levels of Pt, 99 keV and 130 keV, are populated by either EC of Au(fi/2 = 183 days) or isomeric transition of Pt(fi/2 = 4.1 days). Only a few authors, e.g., [323, 324] reported on the use of Pt, which is produced by thermal neutron activation of " Pt via " Pt(n, y) Pt. The source used in the early measurements by Harris et al. [322, 325] was carrier-free Au diffused into platinum metal. Walcher [326] irradiated natural platinum metal with deuterons to obtain the parent nuclide Au by (d, xn) reactions. After the decay of short-lived isotopes, especially Au(fi/2 = 6.18 days), Au was extracted with ethyl acetate, and the Au/Pt source prepared by induction melting. Buym and Grodzins [323] made use of (a, xn) reactions when bombarding natural iridium with... 

In 1937 the element of the atomic number 43 was discovered by Perrier and Segre who showed that radioactivity obtained by irradiation of molybdenum with deuterons was due to isotopes of the missing element ekamanganese. The metastable isomers Tc and " Tc had been produced by the nuclear reactions... 

Two main nuclear methods for the formation of the radioactive fluorine have been developed. The first involves a reaction of neon with deuterons, 20Ne(d, a) 18F, using elemental fluorine as a carrier. The second method uses irradiation of natural water with 30-MeV helium-3, [160 (3He,p)18F] or irradiation of lsO-enriched water with 16-MeV protons resulting in [lsO(p,n)18F]. This is a no carrier method and results in an anionic 18F fluoride. We will review here some of the synthetic ways based on these two major methods for introducing 18F isotope into organic compounds. Many of these compounds have special affinity to certain organs or receptors in the living body. 

All of these initial experiments had been based on the assumption that the reaction of deuterons with would be the most likely reaction in forming To eliminate the possibility of a favored reaction of neutrons with an experiment was devised in which a solution of saturated ammonium nitrate was irradiated with neutrons. It was expected that no detectable amount of radiocarbon would be produced. Instead, a relatively small amount of the precipitate paralyzed the screen-wall counter Within a few month s time, despite strong theoretical arguments to the contrary, it was demonstrated experimentally that the thermal neutron mode of production was heavily favored and that the half-life was on the order of years or millenia (15). 

Since about 1930 a great number of papers concerned with radiation effects on catalysts have been produced, but very little work in comparison has been done with ion bombardment. The great majority of the papers dealt with 7-, X-ray, electron or thermal neutron irradiations. Some of the later studies using protons, deuterons and a-particles are to some extent comparable to irradiations with ions . In some cases enhancement of the catalytic activity was found, in others in-... 

The first microgram quantities of plutonium were produced [S6] in 1942 by irradiation of natural uranium with deuterons in the cyclotron of Washington University in St. Louis. This plutonium was separated at the Chicago Metallurgical Laboratory of the Manhattan Project by Seaborg and his collaborators, who employed the method of carrier precipitation frequently used by radiochemists to extract small amounts of radioactive material present at low concentration. As wartime urgency required that a plutonium separation plant be designed and built before macro quantities of plutonium could be available for process development, it was decided to use the same carrier precipitation process that had successfully produced the first small quantities of this element. 

D.L. Emerson (1975). Production and annealing studies of lead irradiated with protons or deuterons. Radial. Eff. 24, 89-94. 

Even a chemically pure target may yield products of several elem ts, particularly in cyclotron irradiation, where many reaction paths are often possible. In the bombardment of magnesium with deuterons, the following reactions occur ... 

They did not observe any N02" in the proton irradiation of water, but by irradiating diamond dust in water with deuterons, they observed 70% NHs, 24% NO3", and 4% NO2". Gersberg and Kxohn (18)... 

An excellent way of measuring the material loss at the surface is use of thin-layer activation. A thin layer of radioactive tracer is produced on the surface by irradiation with charged particles. This technique can be applied to all types of iron, steel, nonferrous metals and alloys. It is particularly suitable for metal wear studies, because, if done carefully, the charged-particle activation little alters the mechanical properties of the surfaces of specimens. As the charged particles for irradiation, protons, deuterons, a particles, and occasionally He-particles accelerated by a cyclotron or other accelerators are used. Choosing the kind and energy of the charged particles, a radioactive layer of 10-1,000 pm thickness is produced. Typical nuclear reactions used are as follows. 

The majority of radioactive nuclides (radionuclides) are man-made, created by transforming a stable nuclide into an unstable state by irradiation with neutrons, protons, deuterons, alphas, gammas, or other nuclear particles. The source of these particles may be a radionuclide, a nuclear reactor, or a particle accelerator (Van de Graaff, cyclotron, linac, etc.). The tremendous variety of radionuclides discovered in this manner has given rise to many applications in physics, chemistry, biology, and, of course, medicine. The production of those medically useful radionuclides created by exposure to neutrons in a nuclear reactor is discussed in this chapter. 

When matter is irradiated with charged particles (protons, deuterons, helium-3, helium-4), some of the nuclides are transformed by nuclear reactions into radionuclides. The possibility of a nuclear reaction A(a,b)B is determined by the energy Q liberated per reaction. Q can be deduced from the mass difference between starting and end products by ... 

Of course one can also combine a proton and a deuteron irradiation to determine boron and lithium. Irradiating with 7 MeV deuterons and with 10 MeV protons would be a good combination. 

After a 30 min (aluminium-magnesium) or 2 h (aluminium) irradiation with a 4 mA beam of 10 MeV deuterons (degraded to 8.7-8.9 MeV) and removal of a surface layer (2.3.1), Mortier et al. (32) apply the following chemical... 

The yield of the chemical separation was checked in a separate experiment. Zirconium metal doped with 100 /ig/g boron was irradiated with 4.2 MeV deuterons. The induced 511 keV activity was measured repeatedly. Analysis of the decay curve gave the activity. After the measurements was chemically separated and the absorbed activity was measured and compared with the original activity. For the separation described the yield was 85 + 5 % (34). When however some graphite carrier was added before the dissolution, the yield was 98.3 + 7.7 % (36). It is believed that the large standard deviation of these results is due to uncertainties... 

Strijckmans et al. (52) describe the determination of carbon in nickel. After irradiation with 7 MeV deuterons (degraded to 4.1 - 5.0 MeV) the sample is chemically etched in 3 volumes 40 % hydrofluoric acid and 2 volumes 14 M nitric acid and partly dissolved in 25 ml of a solution of 140 mg/1 ammonium hexachloroplatinate in 6 M hydrochloric acid. The ammonium hexachloroplatinate is added to speed up the dissolution. 30 min. is sufficient to dissolve 0.14 - 0.30 g/cm. The volume is adjusted to 50 ml... 

Fig. VI-5 Decay curve of a Nb and Ta sample, irradiated with 5 MeV deuterons...

For the production of I from Cs, the target, CsIO, was irradiated with fast neutrons obtained from the reaction of deuterons on beryllium (109). After irradiation, the cesium iodate was dissolved in an aqueous solution of molecular iodine and the iodine extracted into carbon tetrachloride. Several I,I redox cycles were then carried out and the iodine was finally precipitated as silver iodide. The product was contaminated with I and I (the extent of contamination was not given) formed from iodate. 

Planet pluto) Plutonium was the second transuranium element of the actinide series to be discovered. The isotope 238pu was produced in 1940 by Seaborg, McMillan, Kennedy, and Wahl by deuteron bombardment of uranium in the 60-inch cyclotron at Berkeley, California. Plutonium also exists in trace quantities in naturally occurring uranium ores. It is formed in much the same manner as neptunium, by irradiation of natural uranium with the neutrons which are present. 

Ionic Reactions in TD/D2 Ethane Mixtures. The data in Table III show that deuteron transfer occurs in irradiated mixtures of D2 and ethane as well. Data are shown only for temperatures (<25°C.) at which ionic reactions clearly predominate. Analysis of data concerning thermal atomic and free-radical reactions at higher temperatures will be published elsewhere in the near future. The reaction of D3 + with ethane has been observed directly (1) and postulated (2) by other workers. Both groups have proposed that the sequence initiated by deuteron transfer to ethane proceeds as follows ... 

This is the case for the N(d, p) N reaction, which is exited by a deuteron beam with a 610-keV energy. Figure 6 shows the products of the nuclear reactions taking place upon deuteron irradiation, for the same samples shown in Figure 5. As occurs with hydrogen, nitrogen is also depleted by ion implantation treatment. 

The precursor of ° Ru is ° Rh (tip, = 3 years). It is prepared by irradiating natural ruthenium metal with 20 MeV deuterons, " Ru (d, n) Rh. The target is then allowed to decay for several months to diminish the accompanying Rh activity. In a report on ° Ru Mossbauer spectroscopy [111], the authors reported on spectra of Ru metal, RuOa, and [Ru(NH3)4(HS03)2] at liquid helium temperature in standard transmission geometry using a Ge(Li) diode to detect the 127 keV y-rays. The absorber samples contained 1 g of ruthenium per cm. ... 

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