Author Topic: Radiation  (Read 938745 times)

Offline Luke Pemberton

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Re: Radiation
« Reply #780 on: April 02, 2018, 06:46:32 PM »
The effect of high-energy cosmic rays on humans is unknown but is considered by most authorities not to be of serious concern for exposures of less than a few years.

Care to comment on your this point, that you brought to the forum. It's your information.
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Offline Luke Pemberton

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Re: Radiation
« Reply #781 on: April 02, 2018, 06:51:14 PM »
Cosmic ray fluxes, consisting of completely ionized atomic nuclei originating outside the solar system and accelerated to very high energies, provided average dose rates of 1.0 millirads per hour in cislunar space** and 0.6 millirads per hour on the lunar surface.

Interesting. It would appear that the dose is less on your highly radioactive surface than in cisluanr space. Any comments?

Now let's take a key point about this data and the CRaTER data. See that word in bold - average. Let's investigate the idea of an average and actual dosimeter readings. Let's say that we have 15 days in a row and the dose rate in millirads measured by a detector in space each day follows the sequence.

1 1 1 1 1 2 2 2 2 2 3 3 3 3 3

What is the average daily dose for the 15 days?

What would you average dose read for a mission that occurred during the first 5 days?

Now compare your received dose for the mission with the average daily dose recorded by the detector in space. What can you say about the notion of average dose and actual measured dose over a mission?

Accumulated total dose divided by mission duration is the way to go. I see nothing wrong.  Stay with me.  How can Apollo 11 have less dosage than cislunar background radiation?  How does that work?

I'll do the sums for you then, using your own assumptions of accumulated dose/duration:

The accumulated dose for 15 days would be 30 units, the average dose would be 2 units/day.

If I were to go on a mission in the first five days, my accumulated dose would be 5 units, my average daily dose would be 1 unit/day.

Over to you: Can a mission dose be less than the average dose recorded over a longer time period?
Only two things are infinite, the universe and human stupidity, and I'm not sure about the former - Albert Einstein.

I can calculate the motion of heavenly bodies, but not the madness of people – Sir Isaac Newton.

A polar orbit would also bypass the SAA - Tim Finch

Offline timfinch

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Re: Radiation
« Reply #782 on: April 02, 2018, 06:55:24 PM »
Why are we considering variation in mission duration or even daily radiation dose?  The mission was eight days and that is a given and it matters not what the daily dose was.  It is the accumulated dose that is biologically important.  I am missing your point.
« Last Edit: April 02, 2018, 07:04:28 PM by timfinch »

Offline timfinch

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Re: Radiation
« Reply #783 on: April 02, 2018, 06:57:12 PM »
Do you have reason to disbelieve NASA's statement that cislunar space had a level of 1 millirad/hr?

Offline Luke Pemberton

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Re: Radiation
« Reply #784 on: April 02, 2018, 07:06:42 PM »
Why are we considering variation in mission duration or even daily radiation dose?  The mission was eight days and that is a given and it matter not wath the daily dose was.  It is the accumulated dose that is biologically important.  I am missing your point.

I agree with you, that accumulated dose is important, but as we are dealing with mission doses that are no more than a chest x-ray or CT scan; we can work within acceptable parameters of accumulated dose. Now, let me remind you:

You introduced the notion of daily dose of <0.22 mGr/day and then comparing this to cislunar daily levels.

You told me mission accumulated dose / mission duration was the way to go. I'm using your assumptions.

You now want to move on to data that is representative of 1969 and you cited an average dose of 1 mrad/day. I can only deal with your assumptions of dose / day and the data you present.

So let's go through this again. I have a satellite in space that records the daily dose thus:

1 1 1 1 1 2 2 2 2 2 3 3 3 3 3

What is the average daily dose? Please answer.

What is the average daily dose for an astronaut of they fly a mission on the first five days of the profile above.

What's the problem with using your new data of average dose without understanding fluctuation in the background GCR.
Only two things are infinite, the universe and human stupidity, and I'm not sure about the former - Albert Einstein.

I can calculate the motion of heavenly bodies, but not the madness of people – Sir Isaac Newton.

A polar orbit would also bypass the SAA - Tim Finch

Offline timfinch

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Re: Radiation
« Reply #785 on: April 02, 2018, 07:07:55 PM »
Something has to be wrong.  Either NASA got the GCR radiation of cislunar space wrong or the recorded the mission dose wrong.  Of course there is the possibility it is all right and mission dose represents a stay in LEO and not a lunar transit but who am I to cast stones?

Offline Luke Pemberton

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Re: Radiation
« Reply #786 on: April 02, 2018, 07:11:26 PM »
Something has to be wrong.

You have 15 coins of value 1 1 1 1 1 2 2 2 2 2 3 3 3 3 3

What is the average value of the 15 coins?

What is the average value of the first five coins in the sequence?
Only two things are infinite, the universe and human stupidity, and I'm not sure about the former - Albert Einstein.

I can calculate the motion of heavenly bodies, but not the madness of people – Sir Isaac Newton.

A polar orbit would also bypass the SAA - Tim Finch

Offline timfinch

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Re: Radiation
« Reply #787 on: April 02, 2018, 07:12:25 PM »
Why are we considering variation in mission duration or even daily radiation dose?  The mission was eight days and that is a given and it matter not wath the daily dose was.  It is the accumulated dose that is biologically important.  I am missing your point.

I agree with you, that accumulated dose is important, but as we are dealing with mission doses that are no more than a chest x-ray or CT scan; we can work within acceptable parameters of accumulated dose. Now, let me remind you:

You introduced the notion of daily dose of <0.22 mGr/day and then comparing this to cislunar daily levels.

You told me mission accumulated dose / mission duration was the way to go. I'm using your assumptions.

You now want to move on to data that is representative of 1969 and you cited an average dose of 1 mrad/day. I can only deal with your assumptions of dose / day and the data you present.

So let's go through this again. I have a satellite in space that records the daily dose thus:

1 1 1 1 1 2 2 2 2 2 3 3 3 3 3

What is the average daily dose? Please answer.

What is the average daily dose for an astronaut of they fly a mission on the first five days of the profile above.

What's the problem with using your new data of average dose without understanding fluctuation in the background GCR.

Ok, I'll play along.  Accumulated dose = 30 over 15 days the average dose is 2 units/day.  So is that the tactic?  You want to pretend daily fluctuation occured and sometimes they got less and other times they got more?  Does it matter.  Dosimeters measure accumulated dose.  Where are we going with this?

Offline timfinch

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Re: Radiation
« Reply #788 on: April 02, 2018, 07:13:08 PM »
Something has to be wrong.

You have 15 coins of value 1 1 1 1 1 2 2 2 2 2 3 3 3 3 3

What is the average value of the 15 coins?

What is the average value of the first five coins in the sequence?
one.

Offline timfinch

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Re: Radiation
« Reply #789 on: April 02, 2018, 07:19:52 PM »
So when are we going to talk about the elephant in the room?

Offline timfinch

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Re: Radiation
« Reply #790 on: April 02, 2018, 07:20:40 PM »
Say it with me.  Checkmate!

Offline Luke Pemberton

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Re: Radiation
« Reply #791 on: April 02, 2018, 07:29:07 PM »
You want to pretend daily fluctuation occured and sometimes they got less and other times they got more?  Does it matter.  Dosimeters measure accumulated dose.  Where are we going with this?

I'm not pretending anything, and of course it matters. On one mission your dosimetry will be above the average and on another mission your dosimetry will be below the average. That's the problem with your argument of citing an average dose taken with one detector over many months or years, and then trying to compare dosimetry that is taken over a few days with a completely different detection technique or placement of a detector. It's apple and pears whatever you do.

If you look at the CRaTER data, or even your precious graph, you'd find that fluctuations occur on a daily basis. See those big spikes, that correspond to the SPEs. They might tell you that there are variations. If you understood ExCel, you'd see the thickness of the line is an artefact of plotting over 60 000 varying data points. So yes, the GCR data does vary on a daily basis.

The GCR flux is not constant. It varies slightly daily within a cycle, and is strongly modulated over a single cycle, with further modulation over numerous cycles.

Do you understand the term integrated flux? That was the purpose of the 1 1 1 1 1 2 2 2 2 2 3 3 3 3 3 example.

I defer this to Jay, if he wishes to enter the fray again, and he can offer you the same insight that he offered Jarrah White. He's better at explaining it than I.
« Last Edit: April 02, 2018, 07:34:22 PM by Luke Pemberton »
Only two things are infinite, the universe and human stupidity, and I'm not sure about the former - Albert Einstein.

I can calculate the motion of heavenly bodies, but not the madness of people – Sir Isaac Newton.

A polar orbit would also bypass the SAA - Tim Finch

Offline timfinch

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Re: Radiation
« Reply #792 on: April 02, 2018, 07:32:55 PM »
Show me some love and concede.  Nothing wrong with being on the wrong side of the truth as long as you learn from the experience.

Offline Luke Pemberton

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Re: Radiation
« Reply #793 on: April 02, 2018, 07:33:36 PM »
Show me some love and concede.

Jimmy Anderson has just taken England's 4th wicket. They're rampant.

Quote
Nothing wrong with being on the wrong side of the truth as long as you learn from the experience.

I agree, and where I have been leading you since you introduced your 'new data' with the average is the idea of flux. So learn from experience - do you understand the term integrated flux?
« Last Edit: April 02, 2018, 07:36:10 PM by Luke Pemberton »
Only two things are infinite, the universe and human stupidity, and I'm not sure about the former - Albert Einstein.

I can calculate the motion of heavenly bodies, but not the madness of people – Sir Isaac Newton.

A polar orbit would also bypass the SAA - Tim Finch

Offline timfinch

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Re: Radiation
« Reply #794 on: April 02, 2018, 07:34:54 PM »
Show me some love and concede.  Nothing wrong with being on the wrong side of the truth as long as you learn from the experience.

Do you understand what the term integrated flux?
Sure I do and trust me, you don't want to integrate SPE's into your equation.  It is better to pretend there were none.