Radiation

[Luke Pemberton]

I remind you that chasrt not only emcompasses the apollo era it aslo includes the CraTer era as a defacto comparison to the available data on cislunar background radiation.

In the light of all the discussions, interpret the graph in Figure 2, not Figure 1 as you've just posted. How does it compare to the discussions? What can conclude from the graph. Please tell us Timothy. Paint that picture for us, and whether the analysis aligns with all that we've explained.

[timfinch]

Explain to me how you are interpreting this graph.  Are you using the red line or the green.  Maybe an average and if you chose one over the other then why.  Finally tell me the value you extrapolated from this graph that I might consider properly the ramifications.

No, you tell me how you interpret it. It's produced by the CRaTER team that you Timothy, hold with so great authority. You tell use how you interpret it, and then answer the question. Does it meet your criteria or not?

LO: I want this moderated if you can spare the time. I want Timothy to interpret the graph, and answer the question I placed in bold.

I suggest no other person here gives the answers. Over to you Timothy. Interpret that graph.

Whoa, big fellow.  You introduced the graph and I asked for your interpretation first.  Fair is fair.  You brought the witness to the stand then examine the witness that I might consider the testimony.

[Luke Pemberton]

I remind you that chart not only emcompasses the apollo era it aslo includes the CraTer era as a defacto comparison to the available data on cislunar background radiation.

Oh Timothy, you'll get to love me, as that plot includes the CRaTER data at a solar maximum.What does that CRaTER data tell us for GCR dose at solar maximum?

[Jason Thompson]

All the data is lined up numerically from high to low.  If GCR was the dominant component you would expect the curve to be flat

Why? The GCR background is modulated by solar activity and hence is not constant (as is clear from the riginal CraTER graph). If it is not constant the curve cannot be flat.

with a sudden upstart to reflect the SPE component.

Why? SPEs are not events with certain magnitudes, and their directionality will also affect the amount of radiation reaching the detectors. In fact that kind of continuum is exactly what you would expect from something recording radiation reaching a detector in a particular location when the object emitting the radiation is spherical and blasting it off from various points on its surface.

That suggest the SPE component is the major contributor to background radiation.

SPEs are discrete events.

It is also of note that the lowest readings do not suggest a low enough value to have supported a lunar transit.

Virtually the whole left side of that curve falls below 0.2mGy/day.

[Luke Pemberton]

Whoa, big fellow.  You introduced the graph and I asked for your interpretation first.  Fair is fair.  You brought the witness to the stand then examine the witness that I might consider the testimony.

No, I'm asking you a question. Does the graph confirm your initial hypothesis of threshold, yes or no? The burden of proof is on you. I'm just given you another part of the data.

You can read graphs Timothy?

[timfinch]

Whoa, big fellow.  You introduced the graph and I asked for your interpretation first.  Fair is fair.  You brought the witness to the stand then examine the witness that I might consider the testimony.

No, I'm asking you a question. Does the graph confirm your initial hypothesis of threshold, yes or no? The burden of proof is on you. I'm just given you another part of the data.

You can read graphs Timothy?

Is this  a seniority thing?  I asked the first question and as such I should get the first answer.  Let's play fair.  What are you afraid of?

[Jason Thompson]

Appendix B: Calculation of the D1-D2 Dose Rate [54] Many measurements of space radiation have been, and continue to be, made using silicon detectors. In many experiments, the quantities of interest are the fluxes of individual ion species in particular energy bins. Detectors and electronics are optimized accordingly. ACE/CRIS provides a good example of this. In contrast, CRaTER is optimized to measure energy deposition distributions in silicon over a very wide dynamic range. These measurements must E00H13 SCHWADRON ET AL.: LUNAR RADIATION AND SPACE WEATHERING E00H13 10 of 13 be converted to tissue dose. As in analysis done by other groups [e.g., Beaujean et al., 2002] a single scaling factor is used to perform this conversion. [55] In principle, calculation of dose requires knowledge of the charge, mass, and energy of each incident particle in order to calculate its LET in water; the LET values of individual particles are multiplied by path length (detector thickness), summed and divided by the mass. In practice, we do not have this detailed information, so instead we add together all the energy depositions in silicon and divide by the mass to get the dose in silicon. We then need to account for the difference in ionization potentials between silicon and water. The ionization potential appears in the logarithmic term in the Bethe-Bloch equation, and introduces energy dependence when the ratio of dE/dx in two materials is computed. At typical GCR energies of several hundred to a few thousand MeV/nuc, the ratio of dE/dx in the two materials is fairly constant. The lower ionization potential of water compared to silicon results in larger energy depositions per unit mass for a particle with a given charge and velocity. Careful study shows that for the GCR energy range of interest the ratio of dE/dx in silicon to dE/dx in water is about 1.75, an estimate that includes d-ray escape from finite depths of silicon. This also includes the effect of the higher density of silicon, which must be factored out, resulting in a multiplicative factor of 1.33 to be applied to the silicon dose. This can be seen from considering the sums over energy depositions, DEi, in the two materials:

Now show that what that statement means is actually that the data presented must be multiplied by 1.3 rather than that this factor has already been included in the data presented.

[timfinch]

All the data is lined up numerically from high to low.  If GCR was the dominant component you would expect the curve to be flat

Why? The GCR background is modulated by solar activity and hence is not constant (as is clear from the riginal CraTER graph). If it is not constant the curve cannot be flat.

with a sudden upstart to reflect the SPE component.

Why? SPEs are not events with certain magnitudes, and their directionality will also affect the amount of radiation reaching the detectors. In fact that kind of continuum is exactly what you would expect from something recording radiation reaching a detector in a particular location when the object emitting the radiation is spherical and blasting it off from various points on its surface.

That suggest the SPE component is the major contributor to background radiation.

SPEs are discrete events.

It is also of note that the lowest readings do not suggest a low enough value to have supported a lunar transit.

Virtually the whole left side of that curve falls below 0.2mGy/day.

Didn't you get the memo?  That is uncorrected data, and to properly evaluate it you should average out daily dose rates making it 1/24 the size it currently is.  It really doesn't matter what value you select as a representative dose foe a lunar transit.  Any dose at all is too high because of VAB an Lunar radiation but let's play this game anyway.  What value would you select as a realistic value for the next lunar mission?

[Luke Pemberton]

Is this  a seniority thing?  I asked the first question and as such I should get the first answer.  Let's play fair.  What are you afraid of?

I say that graph refutes your hypothesis.

[timfinch]

Appendix B: Calculation of the D1-D2 Dose Rate [54] Many measurements of space radiation have been, and continue to be, made using silicon detectors. In many experiments, the quantities of interest are the fluxes of individual ion species in particular energy bins. Detectors and electronics are optimized accordingly. ACE/CRIS provides a good example of this. In contrast, CRaTER is optimized to measure energy deposition distributions in silicon over a very wide dynamic range. These measurements must E00H13 SCHWADRON ET AL.: LUNAR RADIATION AND SPACE WEATHERING E00H13 10 of 13 be converted to tissue dose. As in analysis done by other groups [e.g., Beaujean et al., 2002] a single scaling factor is used to perform this conversion. [55] In principle, calculation of dose requires knowledge of the charge, mass, and energy of each incident particle in order to calculate its LET in water; the LET values of individual particles are multiplied by path length (detector thickness), summed and divided by the mass. In practice, we do not have this detailed information, so instead we add together all the energy depositions in silicon and divide by the mass to get the dose in silicon. We then need to account for the difference in ionization potentials between silicon and water. The ionization potential appears in the logarithmic term in the Bethe-Bloch equation, and introduces energy dependence when the ratio of dE/dx in two materials is computed. At typical GCR energies of several hundred to a few thousand MeV/nuc, the ratio of dE/dx in the two materials is fairly constant. The lower ionization potential of water compared to silicon results in larger energy depositions per unit mass for a particle with a given charge and velocity. Careful study shows that for the GCR energy range of interest the ratio of dE/dx in silicon to dE/dx in water is about 1.75, an estimate that includes d-ray escape from finite depths of silicon. This also includes the effect of the higher density of silicon, which must be factored out, resulting in a multiplicative factor of 1.33 to be applied to the silicon dose. This can be seen from considering the sums over energy depositions, DEi, in the two materials:

Now show that what that statement means is actually that the data presented must be multiplied by 1.3 rather than that this factor has already been included in the data presented.

I confess,  There was nothing in the down load that indicated it was not raw data but theoretically I imagine it could have been.  What can I tell you?

[Jason Thompson]

All the data is lined up numerically from high to low.  If GCR was the dominant component you would expect the curve to be flat

Why? The GCR background is modulated by solar activity and hence is not constant (as is clear from the riginal CraTER graph). If it is not constant the curve cannot be flat.

with a sudden upstart to reflect the SPE component.

Why? SPEs are not events with certain magnitudes, and their directionality will also affect the amount of radiation reaching the detectors. In fact that kind of continuum is exactly what you would expect from something recording radiation reaching a detector in a particular location when the object emitting the radiation is spherical and blasting it off from various points on its surface.

That suggest the SPE component is the major contributor to background radiation.

SPEs are discrete events.

It is also of note that the lowest readings do not suggest a low enough value to have supported a lunar transit.

Virtually the whole left side of that curve falls below 0.2mGy/day.

Didn't you get the memo?  That is uncorrected data, and to properly evaluate it you should average out daily dose rates making it 1/24 the size it currently is.

Averaging out the data won't make it get any higher. Having fewer data points won't alter the magnitude.

It really doesn't matter what value you select as a representative dose foe a lunar transit.

That was literally your whole argument up until you find yourself unable to defend it. Page after apge after page is you insisting that GCR has to be some magical threshold minimum. Now it doesn't matter?

Any dose at all is too high because of VAB an Lunar radiation but let's play this game anyway.

Also wrong for reasons gone into at length on this thread.

[timfinch]

Is this  a seniority thing?  I asked the first question and as such I should get the first answer.  Let's play fair.  What are you afraid of?

I say that graph refutes your hypothesis.

Could you punctuate that response with a value you interpreted from the graph to help me understand your position.  Who knows, I might agree with you.  I am not sure of the relevancy of the graph as it states it is a neutron flux derived determination and I am unfamiliar with the specifics but I don't discount the information.

[Jason Thompson]

I confess,  There was nothing in the down load that indicated it was not raw data but theoretically I imagine it could have been.  What can I tell you?

You can tell us why 'imagining' is a substitute for finding out for sure when insisting we had to correct the data by that factor earlier.

[timfinch]

All the data is lined up numerically from high to low.  If GCR was the dominant component you would expect the curve to be flat

Why? The GCR background is modulated by solar activity and hence is not constant (as is clear from the riginal CraTER graph). If it is not constant the curve cannot be flat.

with a sudden upstart to reflect the SPE component.

Why? SPEs are not events with certain magnitudes, and their directionality will also affect the amount of radiation reaching the detectors. In fact that kind of continuum is exactly what you would expect from something recording radiation reaching a detector in a particular location when the object emitting the radiation is spherical and blasting it off from various points on its surface.

That suggest the SPE component is the major contributor to background radiation.

SPEs are discrete events.

It is also of note that the lowest readings do not suggest a low enough value to have supported a lunar transit.

Virtually the whole left side of that curve falls below 0.2mGy/day.

Didn't you get the memo?  That is uncorrected data, and to properly evaluate it you should average out daily dose rates making it 1/24 the size it currently is.

Averaging out the data won't make it get any higher. Having fewer data points won't alter the magnitude.

It really doesn't matter what value you select as a representative dose foe a lunar transit.

That was literally your whole argument up until you find yourself unable to defend it. Page after apge after page is you insisting that GCR has to be some magical threshold minimum. Now it doesn't matter?

Any dose at all is too high because of VAB an Lunar radiation but let's play this game anyway.

Also wrong for reasons gone into at length on this thread.

When you really think about it.  If you had a dosimeter that recorded at hourly intervals would and average reading be indicative or would you need to multiply the average by 24 to get a daily dose.  I'm just wondering out loud.  Any thoughts in this regard?

[Luke Pemberton]

I confess,  There was nothing in the down load that indicated it was not raw data but theoretically I imagine it could have been.  What can I tell you?

I can tell you. The paper that I have recently posted includes the 1.33 factor. Care to comment on why the graph no longer supports your hypothesis?

Further, that paper also tells you that there is a possibility of double counting in the thin-thick detetor set up. There is also an overlap between LET. I cite the authors:

By studying the LET spectra in these detectors, we find that the appropriate breaking point for LET between D1
and D2 is at 20.1 keV/mm, which occurs in ADU 38 for D1 and ADU 920 for D2. The total dose in deposited in the
D1-D2 detectors is the sum of the dose from independent measurements in D1 (ADU range 38–4095) and from D2
(ADU range 7–920). If the same measurement results in both D1 and D2 deposited energies, then we take the
deposited energy in D1 as the contributor to dose.

Please take this statement and explain why you cannot simply plot your D1 and D2 doses on ExCel, and why this approach might not provide an accurate assessment of the dose.