Difference between revisions of "Solutions 5"

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(Created page with "1:<br> #Thermal neutrons have a kinetic energy of about 0.025eV #Fast neutrons are “braked” with elastic collisions with particles with the same size as the neutrons. A mod...")
 
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#Thermal neutrons have a kinetic energy of about 0.025eV
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#Thermal neutrons have a kinetic energy of about 0.025eV  
#Fast neutrons are “braked” with elastic collisions with particles with the same size as the neutrons. A moderator also needs to have a low cross-section for absorbing neutrons.
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#Fast neutrons are “braked” with elastic collisions with particles with the same size as the neutrons. A moderator also needs to have a low cross-section for absorbing neutrons.  
#A moderator is a material that brakes the neutrons, for instance H<sub>2</sub>O, D<sub>2</sub>O, C, Be. A neutron absorbent catches the neutrons and reacts with the neutron. Good absorbants are borium and gadolinium.
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#A moderator is a material that brakes the neutrons, for instance H<sub>2</sub>O, D<sub>2</sub>O, C, Be. A neutron absorbent catches the neutrons and reacts with the neutron. Good absorbants are borium and gadolinium.  
#From the nuclide carte we can see that <sup>3</sup>He has a high cross-section for the n,p-reaction.
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#From the nuclide carte we can see that <sup>3</sup>He has a high cross-section for the n,p-reaction.  
#The reaction <sup>3</sup>He+n arrow <sup>3</sup>H<sup>+</sup>+<sup>1</sup>H(+<sup>2</sup>e<sup>-</sup>). The charged particles from the reaction creates more ionisations when they travel towards the anode and the cathode, this gives a electric signal.
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#The reaction <sup>3</sup>He+n arrow <sup>3</sup>H<sup>+</sup>+<sup>1</sup>H(+<sup>2</sup>e<sup>-</sup>). The charged particles from the reaction creates more ionisations when they travel towards the anode and the cathode, this gives a electric signal.  
#The Q-value from the reaction is 764 keV, the reaction is exothermic.
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#The Q-value from the reaction is 764 keV, the reaction is exothermic.  
#<sup>3</sup>H<sup>+</sup> and <sup>1</sup>H<sup>+</sup> is created.
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#<sup>3</sup>H<sup>+</sup> and <sup>1</sup>H<sup>+</sup> is created.  
 
#The two products in the reaction recives opposing recoils 180 degrees. Conversion of momentum m<sub>1</sub>v<sub>1</sub>=m<sub>2</sub>v<sub>2</sub> gives: <br>
 
#The two products in the reaction recives opposing recoils 180 degrees. Conversion of momentum m<sub>1</sub>v<sub>1</sub>=m<sub>2</sub>v<sub>2</sub> gives: <br>
  
<math>m_{1}^{2}v_{1}^{2}=m_{2}^{2}v_{2}^{2}\leftarrow m_{1}E_{1}=m_{2}E_{2}\leftarrow E_{1}=\frac{m_{2}}{m{1}}E_{2}=\frac{1}{3}E_{2}</math>
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<math>m_{1}^{2}v_{1}^{2}=m_{2}^{2}v_{2}^{2}\rightarrow m_{1}E_{1}=m_{2}E_{2}\rightarrow E_{1}=\frac{m_{2}}{m{1}}E_{2}=\frac{1}{3}E_{2}</math>
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<math>E_{1}+E{2}=Q=764 keV\rightarrow E_{1} = 190 Kev, E_{2}=570 keV</math>

Revision as of 11:54, 18 June 2012

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  1. Thermal neutrons have a kinetic energy of about 0.025eV
  2. Fast neutrons are “braked” with elastic collisions with particles with the same size as the neutrons. A moderator also needs to have a low cross-section for absorbing neutrons.
  3. A moderator is a material that brakes the neutrons, for instance H2O, D2O, C, Be. A neutron absorbent catches the neutrons and reacts with the neutron. Good absorbants are borium and gadolinium.
  4. From the nuclide carte we can see that 3He has a high cross-section for the n,p-reaction.
  5. The reaction 3He+n arrow 3H++1H(+2e-). The charged particles from the reaction creates more ionisations when they travel towards the anode and the cathode, this gives a electric signal.
  6. The Q-value from the reaction is 764 keV, the reaction is exothermic.
  7. 3H+ and 1H+ is created.
  8. The two products in the reaction recives opposing recoils 180 degrees. Conversion of momentum m1v1=m2v2 gives:

[math]m_{1}^{2}v_{1}^{2}=m_{2}^{2}v_{2}^{2}\rightarrow m_{1}E_{1}=m_{2}E_{2}\rightarrow E_{1}=\frac{m_{2}}{m{1}}E_{2}=\frac{1}{3}E_{2}[/math]

[math]E_{1}+E{2}=Q=764 keV\rightarrow E_{1} = 190 Kev, E_{2}=570 keV[/math]