Abstract
The CNO cycle is one of the fundamental processes of hydrogen burning in stars. The first reaction of the cycle is the radiative proton capture on
$$^{12}$$
12
C and the rate of this
...$$^{12}$$
12
C(p,
$$\gamma $$
γ
)
$$^{13}$$
13
N reaction is related to the
$$^{12}$$
12
C/
$$^{13}$$
13
C ratio observed e.g. in the Solar System. The low-energy cross section of this reaction was measured several times in the past, however, the experimental data are scarce in a wide energy range especially around the resonance at 1.7 MeV. In the present work the
$$^{12}$$
12
C(p,
$$\gamma $$
γ
)
$$^{13}$$
13
N cross section was measured between 300 and 1900 keV using the activation method. This method was only used several decades ago in the low-energy region. As the activation method provides the total cross section and has uncertainties different from those of the in-beam
$$\gamma $$
γ
-spectroscopy technique, the present results provide a largely independent data set for future low-energy extrapolations and thus for astrophysical reaction rate calculations.
In order to provide data for the simulation of the astrophysical γ-process, the cross section measurement of the 124Xe(p,γ)125Cs reaction is in progress at MTA Atomki using the activation technique. ...Precise information on the decay characteristics of the reaction products is of crucial importance for measurements carried out using this method. The half-lives of the produced 125Cs and its daughter 125Xe are published in previous works, but with large uncertainties and ambiguous values. To make these nuclear parameters more precise, the half-lives have been re-measured with high precision using γ-spectroscopy. The obtained new half-life values are t1/2 = 44.35 ± 0.29 minutes for 125Cs and t1/2 = 16.87 ± 0.08 hours for 125Xe.
The precise knowledge of the half-life of the reaction product is of crucial importance for a nuclear reaction cross section measurement carried out with the activation technique. The cross section ...of the
151Eu(
α
,
n
)
154Tb reaction has been measured recently using the activation method, however, the half-life of the 10 h isomer in
154Tb has a relatively high uncertainty and ambiguous values can be found in the literature. Therefore, the precise half-life of the isomeric state has been measured and found to be
T
1
/
2
=
9.994
h
±
0.039
h
. With careful analysis of the systematic errors, the uncertainty of this half-life value has been significantly reduced.
PDF
