The paper is available online:
The results of cross-section measurements for the reactions <SUP>209</SUP>Bi(<SUP>12</SUP>C,X)Au, E=4.8 and 25.2 GeV and <SUP>209</SUP>Bi(<SUP>20</SUP>Ne,X)Au, E=8.0 GeV are reported. The observed yields of the gold isotopes show a similar dependence on mass number for each reaction, differing...
ui.adsabs.harvard.edu
The results of cross-section measurements for the reactions $^{209}\mathrm{Bi}(^{12}\mathrm{C},X)\mathrm{Au}$, $E=4.8 \mathrm{and} 25.2$ GeV and $^{209}\mathrm{Bi}(^{20}\mathrm{Ne},X)\mathrm{Au}$, $E=8.0$ GeV are reported. The observed yields of the gold isotopes show a similar dependence on...
journals.aps.org
Its expensive because of the power requirements for running a particle accelerator, which is not a concern for Molly because Tool Constructs handles that.
Ok, this annoys me enough to give a lecture on nuclear physics.
in the paper cited, three cross-sections are provided, for nuclear reactions. Specifically for 209Bi(12C,𝑋)Au at 4.8 and 25.2 GeV, and 209Bi(20Ne,𝑋)Au, at 8.0 GeV. It is important to note that what the papers report are nuclear reaction cross-sections for productions of unstable aurum isotopes, as it's not actually possible to measure the yield of 197Au in the setup.
The reported cross-sections for 196Au and 198Au are S ~ 1 mb for all three reactions. Mb here stands for millibarn, or
1E-31 m^2. Bombardment statistics (total amount of particles the target) was ~ 4E13 particles, which took ~ 13 hours to generate. This translates to the bombarding particle flux F~9E8 particles per second. This number is important, and I'll explain why in a moment.
Now, let's explain what a
nuclear reaction cross-section is. It's a measure of probability of a nuclear reaction occurring. In order to calculate the rate of a nuclear reaction, one uses the following equation:
rx=Ф*S*Rho, where rx [particles per unit of time per unit of volume] is the nuclear reaction output, how many reactions happen in a unit of volume in a unit of time. Ф is the bombarding particle flux measured in [particles per surface area per unit of time] - how many particles bombard the surface of the target in a unit of time. Rho is the particle density of the target [particles per unit of volume], which is, in case of Bismuth, 2.828E28 particles/m^3.
So, we have two constants, S and Rh, giving us the nuclear reaction yield of
rx~3E-3*Ф. Let's discuss Ф. Using
Large Hadron Collider as the largest heavy particle accelerator out there, full power beam current is ~0.6 A. That's 3.22E14/Z particles per second, where Z is atomic number of the particle, which I'll take as ~ 10 (6 for C, 10 for Ne). This means that the maximum expected particle yield of gold one can dream of with particle accelerators is rx~3E-3*3E13=1E14 [particles/m*s]. What's the meter in the denominator? That's the thickness of the layer at which reaction can be expected to occur. We can estimate it (using overestimation) as the maximum projected range. To calculate it, I used
SRIM software. At 5 GeV the projected range is 60 mm. At 25 GeV it's ~500 mm. For 20Ne at 8 GeV, the projected penetration range is 33 mm. So, I'll roughly estimate the volume to be 100 mm or 0.1 m. This gives us the maximum achievable reaction rate of 1E13 [particles/s]. With TTC that's 1E14 particles/s.
Now, how large is that number? Well, atomic density of Au is 5.904E28 particles / m^3, or 5.904E22 particles/cm^3. This means, that in order to transmute one cubic centimeter of Au using particle accelerator method, with some very, very generous assumptions, one would need ~6E22/1E14=6E8 seconds, or
~20 years.
And no, you don't just scale this with power, building new and more powerful particle accelerators in cutting edge engineering and science, with stuff like particle beam attenuation requiring a lot of research.
So, again, completely impractical.