Investigation of the thermal Al-26(n, p(i))Mg-26 and Al-26(n, alpha(i))Na-23 reactions

A homogeneous deposit of (2.58 +/- 0.12) x 10(17) Al-26 atoms was produced applying the method of electrodeposition. With this target, the Al-26(n(th) , p(i))Mg-26 and the Al-26(n(th), alpha (i))Na-23 reactions were studied at the high flux reactor of the ILL in Grenoble. Thermal cross section values for five transitions were obtained. The value for the Al-26(n(th), p(0))Mg -26 cross section, (8.1 +/- 0.8) mb, is a factor 3 lower than reported in t he literature. For the Al-26(n(th),p(1))Mg-26 cross section, a value of (19 42 +/- 95) mb was found, which is in reasonable agreement with the literatu re values. The result obtained for the Al-26(n(th), p(2))Mg-26 cross sectio n, (17 +/- 4) mb, lies more than a factor 10 below the upper limit reported . A cross section value for the Al-26(n(th), alpha (0))Na-23 reaction of (2 61 +/- 13) mb was found, which is more than a factor 3 lower than reported in the literature. The Al-26(n(th), alpha (1))Na-23 reaction finally was ob served for the first time resulting in an accurate cross section value of ( 74 +/- 4) mb. (C) 2001 Elsevier Science B.V. All rights reserved.