Why cosmic ray intensity needs correction with pressure?

In summary, the conversation discusses the use of pressure correction in measuring cosmic ray intensity. The equation used is I=Io*exp(-a(Pi-Pm)), where Io is the recorded intensity, a is a constant, Pi is the atmospheric pressure at the time of measurement, and Pm is the mean pressure in a particular area. The goal of the correction is to account for the decrease in cosmic ray flux due to higher atmospheric pressure. However, there is confusion about the interpretation of the parameters and the contradiction of the correction resulting in a lower intensity. Further discussion and clarification is needed.
  • #1
sctheorist
4
0
Hi guys,
I cannot understand why we need to correct cosray intensity with pressure and why the equation that describes the phenomenon is I=Io*exp(-a(Δp))? I want to know the phsyical meaning of this(i assume,experimental) result...

Thank you...
 
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  • #2
More context would help.
A correction where, and depending on which pressure?
 
  • #3
By pressure I mean the atmospheric pressure above the neutron monitor for example..The exact equation is:

I=Io*exp(-a(Pi-Pm)) where:

I=corrected with pressure intensity of cosray
Io=the intensity recorded by the neutron monitor
a= constant(namely the pressure coefficient)
Pi=the atm. pressure at the time of measurment
Po=the mean value of pressure in a particular amplitude where the measurment is taken

thanks...
 
  • #4
The higher the pressure, the more material (air) is above you and the fewer cosmic rays get through.
 
  • #5
Look Vanadium 50,

if the pressure is Pi>Pm then the argument in the exp is negative(a is positive) and exp(-a(Pi-Pm) is less than 1.So the corrected value I is less than the recorded Io,which doesn't make sense. In high pressure you supposed to record a value i.e. Io=40 and the correction should be I>Io because high pressure prevents you to count all events available,right?That's a contadiction if I am not wrong...
 
  • #6
Look, sctheorist (why so rude?) the sign of the correction depends on the sign of a.
 
  • #7
No no you misunderstood my friend...I used "look"' in a friendly manner..Maybe it's because I'm not american..Seriously I didn't mean to offend you or something..In my language this phrase has a different meaning..Anyway...

I had a thought today about that..Maybe it has something to do with the equation I=Io*exp(-μχ) that refers to an absorber above your detector. χ being the length of the path within the absorber that the particle crosses..
 
  • #8
Maybe it is just the interpretation of the parameters:
sctheorist said:
By pressure I mean the atmospheric pressure above the neutron monitor for example..The exact equation is:

I=Io*exp(-a(Pi-Pm)) where:

I=corrected with pressure intensity of cosray
Io=the intensity recorded by the neutron monitor
a= constant(namely the pressure coefficient)
Pi=the atm. pressure at the time of measurment
Po=the mean value of pressure in a particular amplitude where the measurment is taken

thanks...
If I0 corresponds to Pm (I think this should be P0) and I corresponds to Pi and a is positive:
Pi-Pm>0 (more pressure at i) corresponds to I<I0 (lower neutron flux at i).
 

1. Why does cosmic ray intensity need to be corrected for pressure?

Cosmic rays are high-energy particles that originate from sources outside our solar system. As they travel through space, they can interact with particles in the Earth's atmosphere, causing them to lose energy and decrease in intensity. The higher the atmospheric pressure, the more particles there are for the cosmic rays to interact with, resulting in a decrease in intensity. Therefore, in order to accurately measure cosmic ray intensity, corrections for pressure must be made.

2. How does pressure affect cosmic ray intensity?

As mentioned earlier, the higher the atmospheric pressure, the more particles there are for cosmic rays to interact with. These interactions cause the cosmic rays to lose energy, resulting in a decrease in intensity. This means that higher pressure levels will lead to a lower measured intensity of cosmic rays.

3. Why is pressure correction important for studying cosmic rays?

Cosmic rays play a crucial role in various fields of study, such as astrophysics, cosmology, and planetary science. They provide valuable information about the composition and structure of our universe. However, in order to accurately interpret data and make meaningful conclusions, it is essential to account for external factors that can affect cosmic ray measurements, such as pressure. Therefore, pressure correction is crucial for obtaining reliable and accurate data.

4. How is pressure correction for cosmic ray intensity calculated?

The correction for pressure is typically calculated using a formula that takes into account the atmospheric pressure at the location of the measurement, as well as the particle's energy and type. This formula is based on the understanding of how cosmic rays interact with particles in the atmosphere and how pressure affects these interactions.

5. Are there any other factors that need to be corrected for when measuring cosmic ray intensity?

Aside from pressure, other factors that can affect cosmic ray intensity include the Earth's magnetic field, solar activity, and the instrument's orientation and sensitivity. These factors also need to be taken into account and corrected for in order to obtain accurate measurements of cosmic ray intensity.

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