How far do gamma rays extend from an accelerator?

[Rev. Cheeseman]

According to https://www.osti.gov/servlets/purl/7234564, the HERMES III which stand for High Energy Radiation Megavolt Electron Source accelerator is "capable of delivering a peak dose of ~100 krad (CaF2) over a useful area of ~1000cm2 (area where dose is greater than 50% of the peak dose) in a pulse on the order of 20ns".

I'm bad at math but I'm curious, is area of 1000cm2 after we convert to radius in feet is indeed a large area? How do we convert 1000cm2 to feet?

 

[Vanadium 50]

How do we convert 1000cm2 to feet?

You don't. One is an area, the other is a length.

The radius of a circle with area 1000 cm2 is 7 inches. About the size of a pizza.

What is the safe distance from gamma rays

That's a completely different question, and the answer is "once you're behind the shielding".

 

[Rev. Cheeseman]

You don't. One is an area, the other is a length.

The radius of a circle with area 1000 cm2 is 7 inches. About the size of a pizza.
That's a completely different question, and the answer is "once you're behind the shielding".

So it is considered as a "large area" only when we are talking about gamma rays then. Correct?

So in a nuclear explosion, the gamma radiation keeps extending as long as there is no barrier, shield, etc.?

 

[Ibix]

So it is considered as a "large area" only when we are talking about gamma rays then. Correct?

I don't know if you are understanding what is being measured. If I'm understanding correctly, the device behaves a bit like a laser pointer, but emitting very powerful gamma rays instead of light. The 1000cm² is the size of the spot it makes on the wall.

So in a nuclear explosion, the gamma radiation keeps extending as long as there is no barrier, shield, etc.?

Gamma radiation is just like light only higher frequency. It'll keep going in a straight line until stopped. But (like the visible flash from an explosion) the radiation spreads out, so is dimmer the further away you are. So the further away you are from an explosion the better. With something emitting a beam, like the HERMES device you cited, the radiation spreads much less - so you either need to be begind a shield or not in the line of fire.

 

[Vanadium 50]

So it is considered as a "large area" only when we are talking about gamma rays then. Correct?

I don't know. How long is a piece of string? 14" diameter is huge if you're talking about silicon wafers, and not so huge if you're talking about buildings. For pizza, 14" is large, 16" is extra large.

 

[Rev. Cheeseman]

I don't know. How long is a piece of string? 14" diameter is huge if you're talking about silicon wafers, and not so huge if you're talking about buildings. For pizza, 14" is large, 16" is extra large.

Gotcha. How do we convert cm^2 to radius in inches? I tried some online converters but I'm not sure if they are correct.

 

[A.T.]

Gotcha. How do we convert cm^2 to radius in inches? I tried some online converters but I'm not sure if they are correct.

Have you tried searching "cm^2 to square inches" then "radius from circle area"?