Rapor 1960-1969 yılları

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A home-made neutron crystal spectrometer for research and training
(T.A.E.C., Çekmece Nuclear Research Center, 1965-11) Akyüz, R. Ö.; Cansoy, Ç.; Domaniç, F.; TAEK-ÇNAEM
In order to make experimental research in the field of low energy nuclear physics, a crystal neutron spectrometer is constructed in ÇNAEM. The energy range is between 0,025 - 6 eV. The available monochromator single crystals are Be, NaCl, (CaCO3), Pb. The minimum precise rotation of spectrometer is 1 minute of arc in Bragg angle. Two Soller type collimators, one from reactor to crystal and the other from sample to counter, are used. The net angular divergence is approximately 5 minutes of arc. Counting system consists of two channels, one of which is used for monitoring the reactor. Counter tubes are B10 enriched BF3 proportional counters. The main problem in construction was, to design and give precise movement to the heavy crystal shielding.
A study of the structure change of water by measuring the sound velocity
(T.A.E.C. Çekmece Nuclear Research And Training Center, 1968-06) Yazgan, Ertuğrul; TAEK-ÇNAEM
The sound velocity has been measured in twice distilled water between 1-40°C with 0.5°C temperature intervals. The differences between the calculated velocities using a fifth degree polinom which was obtained by a computer and the measured velocities were plotted as a function temperature. It was noticed that at some temperatures this curve has not a random distribution character. The investigations showed that, at same temperatures Qurashi and Ahsanullah observed a series of discrete jumps in the activation energy of viscous flow of water, and Ahsanullah found discontinuities in the thermal expansion of water. The relationships among those three phenomens were investigated.
Crystal spectrometer measurement of Çekmece TR-1 thermal neutron spectrum
(T.A.E.C., Çekmece Nuclear Research Center, 1964) Domaniç, F.; TAEK-ÇNAEM; Akyüz, Ö.; Bayvas, F.; Cansoy, Ç.
The Thermal Neutron Spectrum of Çekmece TR-1 was measured by using a double drystal spectrometer and NaCf crystal with its (200) plane as monochromator. The neutron energy which corresponds to the maximum of thermal flux distribution was found to be E(0) = 0,0595 ev. Assuming that the flux distribution to be Maxwellian an attempt was made to analyze the measured data to evaluate the effective neutron temperature in the beam hole. Because the theoretical expressions given in the latest publications are found to be unsatisfactory in representing neutron reflectivity for slow neutrons, an experiment was carried out to determine the reflectivity in dependence of neutron energy, the results of the experiment showed that the reflectivity in proportional to E-0,45. By using this empirical relation the effective neutron temperature was found to be ≈ 337°K.
Determination of thallium by activation analysis based on the reaction 203T1 (n, 2n) 202T1
(T. A. E. C., Çekmece Nuclear Research Center, 1966-09) Erben, M. Talat; Okar, Sevim; TAEK-ÇNAEM
Thermal neutron activation of thallium leads to 3.9-year 204T1 and 4.3-min. 206T1 isotopes which are not gamma emitters. However, a method of analysis based on the reaction 203T1(n, γ) 204T1 has been developed by Delbecq et al., and used to detect thallium amounts with a sensistivity of 0.1 µg. In spite of this high sensitivity, this method has the disadvantage of measuring the beta activity and therefore is not very specific. In the present note an activation analysis based on the reaction 203T1(n,2n) 202T1 is discussed. The product isotope 202T1 has a convenient half-life of 12 days and is a gamma emitter, thereby makes the determination specific. On the other hand, owing to the rather high threshold (8-9 MeV) for this reaction the sensitivity is only about 20 µg of thallium for samples irradiated for 30 hours in the close-vicinity of the reactor fuel in a total flux of 10(13) n/cm2/sec.
Discussion on the possibilities of producing mutants resistant to peronospora tabacina (blue mold disease) of tobacco plants by seed treatment with ionizing radiation
(T.A.E.C., Çekmece Nuclear Research Center, 1964-11) TAEK-ÇNAEM; Polar, Emine
Inversion of the cyanide group into iso-cyanide under gamma irradiation
(T.A.E.C., Çekmece Nuclear Research Center, 1965-10) Erben, M. Talat; Ünseren, Envare; Seber, Nurten; TAEK-ÇNAEM
Infrared spectrophotometric evidence indicates that gamma irradiation of the nitriles causes partial inversion of the cyanide group into iso-cyanide according to the following mechanism: In the gamma flux, some of the cyanide groups are detached from the nitrile as cyan free radicals and, owing to their resonance-hybrid structure, .C=N - <-> - C=N., two distinct recombination processes take place leading partly to the usual cyanide and partly to the iso-cyanide, respectively. From a comparison of the optical densities at the characteristic frequency of the iso-cyanide absorption band in irradiated methacrylonitrile and ethyl iso-cyanide it is concluded that at least 20% of the cyanide groups were transformed into iso-cyanide in a specific sample of methacrylonitrile irradiated to a total dose of 0.1 megarads.
Isotopic and isotonic yields in nuclear fission
(T.A.E.C. Çekmece Nuclear Research Center, 1962) Erben, M. Talat; Güven, Binay; TAEK-ÇNAEM
The curves for isotopic and isotonic fission yields are calculated and shown to be the Weierstrass transforms of the isoboaric yield curve. The Well-known mass asymmetry of the fission is associated with asymmetry in charge and in neutron contents. There are "forbidden" zones at 44 Z 48 and at 64 N 78, where formation probabilities are extremely low. The distribution of the number of neutrons of the fission fragments is much narrower than what would be expected on the basis of the variation ranges for Z and N. The ambiguity existing about whether the fragments of a pair are meant to complement before or after prompt neutron boil-off is removed, and Glendenin's treatment is confirmed. There are indications, which are in full agreement with the properties of Wahl's empirical Z(p) function, that the proton closed shell contribution (if any) to the fine structure observed in the isobaric yield curve may be larger than the contribution of the neutron closed shell. The isotopic yields of the known nuclides are significantly smaller than the yields defined by the full theoretical curves for Z = 38, 39, 40, 41, 52, and 57, indicating that new isotopes of Sr, Y, Zr, Nb, Te, and La are still to be identified as primary fission products from the thermal neutron fission of U(235).
Kinetics of the reaction of Tetrachloro-p-Benzoquinone with TRI-n-Dodecyl amine
(T.A.E.C. Çekmece Nuclear Research Center, 1965-10) Erben, M. Talat; Dinçler, Güngör; TAEK-ÇNAEM
The kinetics of the reaction of chloranil with tri-n-dodecyl amine have been investigated in the temperature range 100-115.5°C and in the concentration range 0.036-0.0697 M. The kinetics follow a simple second-order mechanism. The energy of activation is 19.7 Kcal./mole. The reaction product is a quaternary amnonium salt, (trichloro-p-benzoquinonyl)-tri-n-dodecyl ammonium chloride. The rate constant is given by: k = 5.74 x 10(10) exp(-9950/T) (minute)(-1) (mole)(-1)
Localiztion properties of the unitary representations of the poincare group in field theory
(T.A.E.C., Çekmece Nuclear Research Center, 1968-02) Gürsey, Feza; TAEK-ÇNAEM
On second order correction to the average extrapolation length
(T.A.E.C., Çekmece Nuclear Research Center, 1963) İnönü, E.; TAEK-ÇNAEM
A first-order expression for the average extrapolation length in bare thermal reactors was given previously on the basis, of a many-group calculation. C. Yalçın extended this calculation to second order and obtained a complicated correction term which does not seem easy to apply. His results are analyzed and simplified here by considering the limit for continuous slowing down. It is shown that the second order correction is of the order of d/R, where is the first order average extrapolation length and R is a length which characterizes the size of the reactor.
On the Özemre's approach to the problem of reflected media
(T.A.E.C., Çekmece Nuclear Research Center, 1964-12) TAEK-ÇNAEM; Ertek, Çetin
It is shown that the global method proposed by Özemre for reflected media is based on a tacit assumption which can not hold in general but which turns out to be a fair approximation. The comparison of this method with the two group and the modified one group theories suggests that it occupies a place between them.
On the two dimensional solutions for an elastic semi-infinite medium with couple stress
(T.A.E.C., Çekmece Nuclear Research Center, 1965-04) Şuhubi, E. S.; TAEK-ÇNAEM
The governing differential equations for an elastic medium with couple stress are solved for a semi-infinite region in static plane deformation by using Fourier transforms. The formal solution can be utilized in a large class of boundary value problems concerning the region in question. For an arbitrary distribution of surface tractions and moments explicit results are given and the solution is obtained for the uniformly distributed surface tractions and moments.
Parameters for the first and second neutron resonance in 149 SM
(T.A.E.C., Çekmece Nuclear Research Center, 1968-06) Akyüz, Ö. R.; Cansoy, Ç.; Domaniç, F.; Örgeevren, Y.; TAEK-ÇNAEM
The total neutron cross section of natural samarium has been measured in the energy range from 0,06 to 1 eV with a crystal spectrometer using the Be(1011) and Be(1231) crystal planes as monochromators.In this region two resonances due to 149Sm are present. After correction for second order contamination caused by the monochromator, Doppler corrections have been applied to both resonances. Corrections for spectrometer resolution were needed only for the second resonance. Both resonances were fitted separately to the Breit-Wigner single-level formula by the method of least squares. The analysis gives the parameters of the resonances as follows: E(o) = 0.0973±0.0012 eV, Q(o) - 18348±376 b, r = 0.0635±0.0013 eV,r(n) = (0.0773±0.0025)x10(-3) eV for the first and E(o) = 0.872±0.012 eV, Q(o) = 2948±68 b, r =0.0635±0.0015 eV, r(n) = (0.1114±0.0041)x10 (-3) eV for the second. The statistical weight factor g is taken to be 9/16 for both levels.
Part I. Thermodynamic functions as particular cases of a single generating function : part II. cyclic properties of thermodynamic functions
(T. A. E. C., Çekmece Nuclear Research Center, 1969-05) Erben, M. Talat; TAEK-ÇNAEM
Bölüm I de, bütün termodinamik potansiyelleri , yani iç enerji E yi, Helmholtz serbest enerjisi F yi, Gibbs serbest enerjisi G yi ve entalpi H yi özel hal olarak veren genel bir jeneratris fonksiyon tarif edilmektedir. Bölüm II de, termodinamik değişkenler ( S, P, T, V ) ile termodinamik fonksiyonlar ( E, F, G, H ) sirküler bir diagram şeklinde dizilmekte ve bu diagram sayesinde pek çok termodinamik bağıntıların biribirinden sirküler permütasyon yoluyla çıkartıla- bildikleri gösterilmektedir.
Reactor kinetics equations according to P1- appoximation
(T.A.E.C., Çekmece Nuclear Research Center, 1969-12) Gençay, Şarman; TAEK-ÇNAEM
In this work we deduce the reactor kinetics equations according to P1-approximation developed by A. Y. ÖZEMRE.
Syntheses based on cholanic acid, ∆ 23 - cholone and 23 - amino norcholane
(T.A.E.C. Çekmece Nuclear Research Center, 1967-04) Ünseren, Envare; TAEK-ÇNAEM
Reduction of cholanic acid (III) with lithium aluminum hydride gave cholanyl alconol (IV). Benzoate, chloride, pyridinium chloride hydrate, ethyl carbonate, S-metnyl xanthate derivatives of cholanyl alcohol have been prepared, ∆23-Cholene has been obtained by the pyrolysis of the last two products. Osmium tetroxide hydroxylation of ∆-cnolene afforded 23,24-dioxy cholane (VIII). Schmid reaction on cholanic acid gave 23-amino norcholane (IX). Acetyl, benzoyl, and tosyl derivatives of the amine have been prepared. Reaction with potassium isocyanate gave norcholanyl urea (IX e). Norcholanic acid (X) has been obtained by the alcaline permanganate oxidation of 23-amino norcholane. Lithium aluminum hydride reduction of norcholanic acid gave norcholanyl alconol (XI).
The most general equations for multigroup neutron diffusion in P1 approximation
(T.A.E.C. Çekmece Nuclear Research Center, 1962) Şuhubi, Erdoğan; Özemre, Ahmed Yüksel; TAEK-ÇNAEM
Starting from the general transport equation and within the limits of P1 approximation, a set of coupled second order partial integro-differential equations is obtained. These equations consider the effect of m groups of retarded neutrons and contain both the first and the second derivatives of the neutron fluxes with respect to the time variable.
Turkish Atomic Energy Commission third activity report of the radioactive fallout laboratory : for the period of August 1965 - July 1966
(Turkish Atomic Energy Commission, 1966) Şenvar, C. B.; Ergin, M.; Usul, F.; Tuğsavul, Ayşen; Yazgan, E.; Saygılı, N.; TAEK
Unified transport theory of two - temperature fully ionized plasmas
(T.A.E.C., Çekmece Nuclear Research Center, 1968-07) Daybelge, Umur; TAEK-ÇNAEM
The transport coefficients of a nonisothermal, fully ionized plasma have been determined without any cut-off procedure. The theory is exact in the sense that it is valid not only for large values of the Coulomb logarithms themselves but also for large values of their arguments. The effect of interactions between electrons and plasma oscilations has been incorporated in the theory. External magnetic fields have not been considered.

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