Difference between revisions of "Notes from July 2nd, 2008 Meeting"

From New IAC Wiki
Jump to navigation Jump to search
Line 13: Line 13:
  
 
target thickness in <math>\frac{Dnuclei}{cm^{2}} \times \sigma in cm^{2}</math>
 
target thickness in <math>\frac{Dnuclei}{cm^{2}} \times \sigma in cm^{2}</math>
 +
 +
==Worst Case Isotropic Neutrons==
 +
 +
Let's say we have:
 +
 +
radius detector = 1 cm
 +
 +
1 meter away
 +
 +
fractional solid angle = <math>\frac{\pi * (1 cm)^{2}}{4 \pi (100cm^{2}} = \frac{1}{4} \times 10^{-4}</math> <= geometrical acceptance
 +
 +
10 \degree efficient of n \degree detection
 +
<math> 10^{4} \frac{photodisintegrations}{sec} \times \frac{1}{4} \cdot 10^{-4} \times 10^{-1} = .025 \frac{events}{sec}</math>
 +
 +
                                  ^          ^
 +
                                  |          |
 +
                                geometry  efficiency
 +
 +
 +
time for 10,sup>4</sup> events = 100 hours for 1%
 +
                                  24 hours for 2%
 +
                                  6 hours for 4%
 +
 +
Therefore, this experiment is do able.

Revision as of 13:40, 3 July 2008

Numbers for rate of Brems intensity spectrum:

[math]\frac{e^{-}}{sec}[/math] = [math]30 \cdot 10^{-3} \frac{Coulomb}{sec} \times \frac{50 \cdot 10^{-9} sec}{10^{-3} sec} \times \frac{1 \cdot e^{-}}{1.6 \cdot 10^{-19}Coulomb} =\gt 9.4 \cdot 10^{12} \frac{e^{-}}{sec} [/math]

[math]10^{-3} \frac{\frac{\gamma 's}{MeV}}{\frac{e^{-}}{radiation lengths}} \times 2 \cdot 10^{-4} radiation lengths \times 15 MeV \times 9.4 \cdot 10^{12} \frac{e^{-}}{sec}=2.8 \cdot 10^{7} \frac{\gamma}{sec}[/math]

Number of ɣ + d -> n + p events/sec

[math]2.8 \cdot 10^{7} \frac{\gamma}{sec} \times 4 \cdot 10^{-4} = 10^{4}[/math]

Probability of Photodisintegration Event

target thickness in [math]\frac{Dnuclei}{cm^{2}} \times \sigma in cm^{2}[/math]

Worst Case Isotropic Neutrons

Let's say we have:

radius detector = 1 cm

1 meter away

fractional solid angle = [math]\frac{\pi * (1 cm)^{2}}{4 \pi (100cm^{2}} = \frac{1}{4} \times 10^{-4}[/math] <= geometrical acceptance

10 \degree efficient of n \degree detection [math] 10^{4} \frac{photodisintegrations}{sec} \times \frac{1}{4} \cdot 10^{-4} \times 10^{-1} = .025 \frac{events}{sec}[/math]

                                 ^           ^
                                 |           |
                               geometry  efficiency


time for 10,sup>4 events = 100 hours for 1%

                                 24 hours for 2%
                                  6 hours for 4%

Therefore, this experiment is do able.