Foundations — Fusion — solar fusion, tokamak (concept)

2.3.24 · D1 · Physics › Modern Physics › Fusion — solar fusion, tokamak (concept)

Yeh page assume karta hai ki aapne parent note ki koi bhi notation pehle nahi dekhi. Hum har symbol ko picture se shuru karke build karenge, ek aisi order mein jahan har symbol sirf pehle se seekhe gaye symbols use karta hai.

1. Nucleus, proton, neutron

Picture: figure s01 dekho. Ek nucleus red balls (protons) aur grey balls (neutrons) ka ek chhota cluster hota hai jo ek saath packed hain. Electrons bahut door bahar rehte hain — hum unhe yahan ignore karte hain kyunki fusion nucleus ke baare mein hai.

Topic ko yeh kyun chahiye: fusion ka matlab hai nuclei ko combine karna. Jab tak aapne cheezein naam nahi di hain, aap unhe combine karne ki baat nahi kar sakte.

2. Nuclide notation ${}_Z^A\text{X}$

Parent note mein ${}_1^2\text{D}$ aur ${}_2^4\text{He}$ jaisi cheezein likhi hain. Aao un numbers ke us stack ko poori tarah unpack karein.

Topic ko yeh kyun chahiye: poori reaction ${}_1^2\text{D}+{}_1^3\text{T}\to {}_2^4\text{He}+n$ inn labels ke saath bookkeeping hi hai. Dhyan do ki totals balance karte hain: protons pehle $=1+1=2$, baad mein $=2+0=2$; balls pehle $=2+3=5$, baad mein $=4+1=5$. Count mein kuch kho nahi jaata — lekin jaise hum dekhenge, mass ka ek chhota sa hissa jaata hai.

3. Nuclei kyun alag dhakelte hain — Coulomb barrier

Picture: figure s02 woh energy "hill" dikhata hai jise do protons ko approach karte waqt chaadhna padta hai (red curve). Door hone par, dhakka halka hota hai. Bahut paas aane par, ek alag, bahut zyada strong attraction (the strong force) achanak aata hai aur unhe kheench leta hai — yahi right side par gahri valley hai.

Topic ko yeh kyun chahiye: parent page par har "insane temperature" aur "compress it" statement purely iss hill ko haraane ke liye hai.

4. Temperature $T$ = particles kitna jiggle karte hain

Picture: figure s01 ki red balls ko vibrate karte imagine karo. Thanda → halka jiggle, woh kabhi s02 ki hilltop tak nahi pahunchenge. Garam → violent jiggle, kuch pairs seedha barrier ke upar se takraa jaati hain.

Topic ko yeh kyun chahiye: "heat to $10^8$ K" ka literal matlab hai "unhe itna jiggle hard banao ki woh Coulomb hill par chadh sakein." $T$ Lawson criterion ke andar bhi aata hai.

5. Mass, mass defect $\Delta m$, aur $E=m{c}^2$

Ab energy release ka dil. Pehle, mass.

$\Delta m=(\sum m_{\text{reactants}})-(\sum m_{\text{products}})$

Yahan $\sum$ (capital sigma) ka matlab sirf "inhe sab jodo" hai.

Topic ko yeh kyun chahiye: parent page par "Derivation of energy released" aur har worked $Q$-value bas masses ko $Q=\Delta m{c}^2$ mein plug karna hai.

6. Binding energy per nucleon $B/A$ — woh "map" jo batata hai ki downhill kaunsa side hai

Picture: figure s03 woh famous Binding Energy per Nucleon Curve hai. Yeh hydrogen se steeply upar jaati hai, iron ke paas peak karti hai (${}^{56}\text{Fe}$, lagbhag $8.8\text{MeV}$ per nucleon), phir dheere dheere girती hai. Curve par jitna upar = zyada tightly bound = zyada stable.

Topic ko yeh kyun chahiye: yahi curve woh reason hai ki fusion bilkul bhi energy release karta hai, aur kyun sirf halke nuclei qualify karte hain.

7. Plasma — reactor ke andar ka stuff

Topic ko yeh kyun chahiye: ek neutral gas ko magnetically pakad nahi sakte. Fusion fuel ko pehle plasma banana padta hai taaki magnets ise hold kar sakein.

8. Magnetic field $\vec{B}$, velocity $\vec{v}$, aur Lorentz force

Picture: figure s04. Ek charged particle $\vec{v}$ along move karta hai; field $\vec{B}$ region mein point karta hai; resulting force $\vec{F}=q\vec{v}\times \vec{B}$ sideways point karti hai, $\vec{v}$ se right angle par. Ek force jo hamesha motion ke sideways ho woh particle ko speed up ya slow down nahi karti — yeh path ko curve karke circle mein le jaati hai. Toh charged particles field lines ke around spiral karte hain unhe cross karne ki bajaye.

Topic ko yeh kyun chahiye: yahi reason hai ki ek magnetic doughnut plasma ko confine kar sakta hai — particles looped field lines se baandhe hote hain. Yeh parent page par "magnet plasma ko heat karta hai" wali galti bhi door karta hai.

9. Confinement symbols ko saath rakhna: $n$, ${\tau }_E$, aur triple product

Topic ko yeh kyun chahiye: yeh single line woh scoreboard hai ki "kya reactor ne jitana cost hua usse zyada energy produce ki."

Prerequisite map

Equipment checklist

Apne aap ko test karo — right side cover karo aur jawab do: