Nuclear Fission

What it shows:

In a nuclear reactor or atom bomb, a fissile material such as 235U tin capture a neutron. The resulting unstable nucleus fragments into two smaller nuclei, releasing free energy and several neutrons (a typical equation is given below). Each of these neutrons can in plough cause the fission of a 235U nucleus. If there is above a disquisitional concentration of fissile material, this chain reaction will keep unaided, and if unregulated can result in a very loud bang.

n + 235U → 236U* → 141Ba + 92Kr + 3n

How information technology works:

Nosotros have a 120 × 70 × 100cm high plexiglass case, onto whose base nosotros set a half dozen × 23 array of mouse traps. 1 A ping-pong brawl rests on each trap. The traps represent the fissile atoms, and the balls the neutrons. When an extra ping-pong brawl is dropped through a hole in the peak of the case, information technology lands and triggers a trap. Now there are two ping-pong balls each capable of setting off a trap. Thus a chain reaction ensues; the whole explosion lasts about three seconds.

Setting it up:

If ever y'all envied those daring bomb disposal guys, here'due south a setup to examination your nerve. The plexiglass case has two portholes, 20cm bore, 10cm above the floor of the example. These are for loading the assurance on the traps. It is advisable to set and lay the traps before you load them. Set each trap, tap it lightly to make sure it isn't too hair-triggered, and slide into position; all traps facing the same style. When loading the balls, rest the brawl on the catch arm on the opposite side to the bait grab; if you lot drop the ball from a pocket-size tiptop it will be less likely to trigger. Start loading the traps on the far side of the example, and work towards you. We plant that a removable partition placed in the example splitting the sample in half allows two people to fix the traps without interfering with each other (or suffering from the other'due south foul-ups). It tin can be removed just before the last traps (continue runway of the least sensitive traps for terminal) are laid and loaded. Our case is mounted on wheels, and then it can be loaded and wheeled (carefully) into the hall when needed. Provide an initiating neutron, and keep the superlative hole covered until detonation.

effigy 1. The loaded trap

mousetrap fission

Comments:

We've got the set-up time down to 15 minutes, and similar all nuclear devices, you only go ane shot at this one.

The mouse trap concatenation reaction originated (nosotros think) from Walt Disney's 1950s film "Our Friend the Cantlet."

J. Higbie (run into Reference) has described a "amend" mousetrap nuclear chain reaction simply we prefer the former fashioned way. Setting upwardly the final few traps while the students await the lecture to begin, dripping brow and shaking hands, certainly adds some drama. We retrieve Enrico Fermi would concur. Reference:
J. Higbie: Am. J. Phys. 48 (1), 62 (1980)

one Mouse traps are 10cm × 5cm in size, manufactured by Woodstream Corp., Lititz, PA or d-Con Corp., Montvale, NJ. Both are available in hardware stores.