| SCI 270: On Nuclear Technology Practice Problems |
Answers are given for your reference only. Please do your part of
the learning, because no one else will be able to do that for you.
Your skills of problem solving are tested and useful in the future. Answers are useless. Acquiring skills and abilities are the goals of learning, marks indications of your performances on these tasks.
The reaction14N (a, p) 17O is _ endo-thermic
Q = _ -1.207 _ MeV/reaction (negative indicating energy required)
= _ -1.17e11 _ J/mol (Energy required per mol of reactions)
The reaction14N (n, p) 14C is _exo-thermic
Mass of 14C = _ 14.003241 _ amu
Q = _ 0.623 _ MeV/reaction
14B ( , b) _14C_
18N ( , b a) _14C_
9Be (6Li, p) _14C_
9Be (7Li, d) _14C_
11B (a, p) _14C_
12C (a, 2p) _14C_
12C (t, p) _14C_
13C (d, p) _14C_
13C (t, d) _14C_
|Now you have learned various types of nuclear reactions.|
|Number of Nuclei|
remain after 24 hours
|59Co (n, g) 60 mCo||20 b|
|59Co (n, g) 60Co||17 b|
_6.14e17 (almost no change)_
|Reaction for the synthesis of a transuranium element|
Transuranium elements are those whose atomic number range from 93 to 103.
Their atomic numbers are higher than that of uranium (92).
Elements Ac to Lw are called actinides, they are a group as are the rare
earth elements (atomic number 57-71).
Transuranium element Np and Pu were obtained using neutron bombardment of uranium. Heavier ones have been synthesized by bombarding Pu with neutrons. Yet, still heavier ones are made by bombarding heavy nuclei with light atomic nuclei:
252Cf + 10B = 247Lw103 + 5 n
252Cf + 11B = 247Lw103 + 6 n
|Reaction for the synthesis of a transactinide element|
Still heavier elements with atomic number greater than 103 are called
transactinide elements. For example,
249Cf98 + 12C = 257Rf104 + 4 n
The most important particles for inducing nuclear reactions are neutrons,
protons, alpha particles, and light atomic nuclei.
A neutron source provide neutrons for inducing nuclear reactions or for other purpose. It can be a mixture of alpha or gamma radionuclides and some light nuclides such as Be, Li, or B. These elements release neutrons when bombarded by alpha particles or gamma rays.
Another neutron source are (p, n) nuclear reactions. The protons from particle acclerators are used to bombard light nuclides, and the reactions release neutrons.
When selectron a neutron source, the energy of the neutrons is an important feature to consider, because the cross section of a nuclear reaction depends on the energy of the neutrons.