Question

hello friends....what is the definition of stopping power and what is the definition of stopping number??

Answer 1

Hi mate. "Stopping power/number" are could refer to a lot of things, from radioactivity through to acoustics. I like a ship analogy. Imagine a LARGE ship, several thousand tons worth. It's doing ... 1 mph. That's actually nearly the speed I limp at, but I DON'T weigh what a ship does. To stop me is easy, to STOP THE SHIP ?!!!!!!!!!!!!!!!!!!! This was recently shown in NY, when a runaway train ploughed into most of a terminus station. The stopping power of the buffers seemed to be ZERO. The stopping NUMBER of the station seemed to be several yards, and an awful lot of masonry.
You can probably shrink this down into alpha beta and gamma radiation and absorbent materials, and likewise with sound intensity.
No idea what the "definitions" are.
bon voyage, et bon chance
http://perendis.webs.com

Answer 2

thx mate osprey , can you help me by send to me a link about atomic stopping number??

Answer 3

https://en.wikipedia.org/wiki/Stopping_power
This link applies to ballistics. Which ain't what you want I know. The scale is too high. But, it's occurred to me that "stopping stuff" could be strongly linked to that good old cop out in maths/physics the exponential function e^-stopping times distance similar to capacitor discharge and a lot of people doing similar things in different ways.
Below could be slightly better, though I've just grabbed it and copy pasted it.
https://www.researchgate.net/post/What_is_the_difference_between_stopping_power_and_mass_stopping_power

Answer 4

This looks even worse, again just copy pasted ...
http://www.med.harvard.edu/JPNM/physics/didactics/physics/charged/lect.html

Answer 5

I get the impression (I guess) that this post is about undergraduate/postgraduate physics ? I've not bet on it, but I'd put 0.01 GBP on it ? Do I win 1p UK money ?

Answer 6

yes my friend now i study Ph.D. in nuclear physics

Answer 7

Brilliant !!! KEEP ME POSTED, maestro .. YUKAWA POTENTIALS HERE WE COME ????????
Bravo

Answer 8

As I remember it, "stopping power" could be important in nuclear reactor control, to stop it going into meltdown (Chernobyl style) or detonating into a bomb (I don't know how similar a nuclear reactor is to a nuclear bomb in terms of design). I'm think of "moderators", such as boron rods which seem to control the "neutron flux" of the various nuclear fissions which generate all that valuable energy. It's something like that if you lower the boron rods into the "nuclear pile", then you increase the moderation, and so lower the energy output (turn the volume down, so to speak), whilst i you raise the boron rods you get a decreased moderation, and an increase in ... (volume up, so to speak).

I think that the element boron has a high "capture cross section" for neutrons, which is one poss reason why it is/was chosen in nuclear reactors.

And I must mention the story of Professor Otto Hahn, and Professor Lise Meitner to whom the discovery of nuclear fission is attributed. The discovery got a Nobel prise for Hahn. I looked this up some time ago, and could find no trace of a Hahn nor a Meitner in a list of prize winners in physics. I doodled a while, and maybe just pressed a button marked chemistry. And, there it was - Hahn's nobel prize (but not shared with Meitner - female, Jewish, spot of Nazi racismm, WW2 etc). Why chemistry, I wondered ? It seems that the WAY the discovery was made needed someone to identify elemnts/compounds in a given (in these case highly and dangerously radioactive) sample. And, that seems to come under the heading of "radio chemical assaying". And, so it's a chemistry prize, rather than a physics prize. When this dawned on me, all I could do was to smile, wryly.

Answer 9

hello mate , how r u?
thx for helping me.. can i know what's ur degree?, and where u live?

Answer 10

Answered before ... but physics and UK. You're the phd student, as I recall. whereabouts are you in your pg studies are you. I ask this because it helps (I need lots of that) me to gauge how to answer any questions/discussion points.
If you like blue birds then ...
http://perendis.webs.com
has a "special" exhibition in honour of nurses. It's not affiliated to anything by itself though.

Answer 11

i am from Baghdad University , from Iraq