Aktivierungsanalyse mit Deuteronen

Abstract

Band 12, Heft 2 1969 WOHLLEBEN und SCHUSTER, Aktivierungsanalyse mit Deuteronen 75 method. (iii) The procedure is simple. The time required for the chemical procedure is about 20 min excluding cooling and equilibration steps. The method seems suitable for the routine and many sample analysis of uranium of the amount higher than 0.1 flg.

Excitation functions of nuclear reactions producing11C

“…In both cases a common excitation energy region of about 9 MeV has been achieved that may be extended with additional data from the literature: The reaction riB(p, n)itC has been studied for Ev< 15 MeV with high projectile energy resolution for lzC spectroscopy [17,22] and at high energies Ep> 40 MeV for reaction mechanism investigations and interpretations in terms of direct mechanisms [23][24][25]. Radiochemical studies are reported [18] for the reaction 1~…”

“…Target thickness was obtained for alB by adopting the llB(p, n)HC cross section a= 282 _+ 28 mb at Ep=10.9MeV from [17] and for l~ by normalization to the maximum value a=267_+40 mb [18] of l~ n)llC at E d =2. 40 MeV with an activation run performed at the 3 MV Hamburg Van de Graaff.…”

“…Only the target foil had to be analyzed. * Union Carbide Corp., Oak Ridge, USA ** Goodfellow Ltd., Cambridge, England a maximum possible kinetic energy of 11C ~ projectile energy loss in target b range R(11C) from [49] d errors are those of reference cross sections [17,18] …”

Precision half-life measurement ofF17

“…Upon close inspection, the article does not mention the presence of 15 O contamination. Furthermore, the 1969 measurement [14], which reported a lower half-life and used the same 29 Si. Hence, for these reasons, we did not include the 1960 measurement in our averaging.…”

“…The lifetime of 17 F is currently known with less precision than the Q-value, while being derived from a number of conflicting measurements resulting in a large Birge ratio of 2.8 [11,12]. Recently, the half-life of 17 F has been measured to a precision of 0.05% [12], disagreeing with three [13][14][15] of the past five measurements [13][14][15][16][17], including a lower precision measurement [13] carried out by the same group. To help clarify the situation, an independent measurement of the 17 F half-life was performed at the Nuclear Science Laboratory of the University of Notre Dame.…”