Modern Physics 5 Question 20

22. Results of calculations for four different designs of a fusion reactor using D-D reaction are given below. Which of these is most promising based on Lawson criterion ?

(2009)

(a) Deuteron density $=2.0 \times 10^{12} cm^{-3}$, confinement time

$$ =5.0 \times 10^{-3} s $$

(b) Deuteron density $=8.0 \times 10^{14} cm^{-3}$, confinement time $=9.0 \times 10^{-1} s$

(c) Deuteron density $=4.0 \times 10^{23} cm^{-3}$, confinement time

$$ =1.0 \times 10^{-11} s $$

(d) Deuteron density $=1.0 \times 10^{24} cm^{-3}$, confinement time

$$ =4.0 \times 10^{-12} s $$

Match the Column

Column I Column II
(A) Nuclear fusion (p) Converts some matter
into energy
(B) Nuclear fission (q) Generally possible for
nuclei with low atomic
number
(C) $\beta$-decay (r) Generally possible for
nuclei with higher atomic
number
(D) Exothermic
nuclear reaction
(s) Generally possible for
weak nuclear forces
Show Answer

Answer:

Correct Answer: 22. (c, d)

Solution:

  1. As given in the paragraph, a reactor is termed successful, if

$$ n t _0>5 \times 10^{14} s cm^{-3} $$



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