Dictionary of Material Science and High Energy Physics Part 2 pptx

... stimulatedemissionofa photonfroma level 1 to a level 2. If level 2 is higher in en-ergy than level 1, the coefficient of stimulatedemission B 21 and stimulated absorption B 12 aregiven byB 12 =g 2 g1B 21 A 21 =8πhν3c3B 21 ,where ... byB 12 =g 2 g1B 21 A 21 =8πhν3c3B 21 ,where A 21 is the Einstein A coefficient for thetransition from 2 →1, and g 2 and g1are the sta-tistical weights or degeneracy factors for level 2 and 1,respectively. ... beexpanded in powers of 1/kR, where R is the ef-fective range and k is the momentum of the par-ticle in units of ¯h. For uncharged particles thisexpression iskcot(δ)=−1/a+k 2 R /2 .In...

... toCv and the specific heat at constant volume, <(E−<E>) 2 >=kBT 2 Cv. energy gap The energy range between thebottom of the conduction band and the top of the valence band in ... shift). energy spectrum The set of energy eigen-states of a physical system. The set of possibleoutcomes of a measurement of the energy; alsoknown as the set of allowed energies. energy- time ... between two points1 and 2, one obtains the Bernoulli equation:P 2 ρ+v 2 2 2 + gz 2 =P1ρ+v 2 1 2 + gz1.europium An element with atomic number(nuclear charge) 63 and atomic weight 151.96.The...

... equa-tion:i¯h∂(r,t)∂t=−¯h 2 2µ∇ 2 r+ V(r)(r,t)µ =m1m 2 m1+m 2 is the reduced mass for particles of mass m1 and m 2 , and r = r1− r 2 are therelative position vectors of particles 1 and 2. Suitable ... 2g1g 2 ) 2 d 2 z1 ,2 =g 2, 1(1 − g1 ,2 )g1+ g 2 − 2g1g 2 dThe linewidth of a laser is given by the convo-lution of the cavity mode structure, gain curve of the lasing medium and transmission curves of ... field.kinetic energy A form of energy associatedwith motion. Every moving particle has kinetic energy. The kinetic energy of a non-relativisticparticle with mass m and speed v is equal to1 2 mv 2 .kinetic...