mean generation timemultiplication factoradjoint fluxThe ambiguity of the mean time from birth of a neutron to its loss in a critical reactor is presented. The neutron lifetime defined as the adjoint-weighted mean loss time should not be interpreted as the mean time from birth of a neutron to...
where Λ is the mean generation time, βi is the fraction of neutrons for each delayed group, λi is the decay constant for each delayed group, and Ci (t) is number of precursors for each delayed group as a function of time. When (1 − βeff) k = 1, the reactor in this case...
mean lifetime 粒子产生后到衰变时为止平均存在的时间。粒子的性质之一。简称寿命,记为τ。当粒子运动速度很快接近光速时,由于相对论效应,平均寿命将比粒子静止时的长。粒子物理中的平均寿命指该粒子静止时的平均寿命。 除了光子、中微子、电子和质子之外,其他粒子都能自发衰变,平均寿命分布在很大的范围。中子的寿命...
[6]. The energy spectrum of the neutrons generated by such a reaction is remarkably asymmetric, showing a distribution extending up to 17MeV with mean value of 2MeV and a mode about 0.75MeV. Such a distribution is Maxwellian in the center-of-mass reference frame and can be represented on...
the NN method demonstrated exceptional resilience with mean errors consistently below 0.005 atτ=0.9\unicode[Times]x03BCs(Fig.1), equivalent to fractional errors smaller than 2% for multiplicities 3, 4 and 5. This approach also presented the smallest error in the average number of neutrons per de...
producing electron bunches with a root mean square (rms) of±2.4%for the peak energy and±11%rms charge stability [55]. Further optimization of the stability and the bunch charge at a fixed peak electron energy is currently under investigation [56]. Acceleration of electrons via LWFA can be...
lNCD=0.88DL2/λL(τLc/λL)1/3, (1) ne,NCD=0.91γ0ncrλL2DL2(τLc/λL)2/3, (2) whereγ0=1+a02/2is the mean Lorentz factor of the laser-driven electrons and
The A-150 plastic kerma-weighted mean neutron energies of the spectra arc given as a function of the neutron emission angle for two different neutron energy thresholds. The present neutron spectra differ in the low energy region from those published in the literature. Deviations of up to 20% ...
Boron carbide has a complex crystal structure [29,30] constituted of nearly regular icosahedra (mean composition B11C, C located on polar sites) interconnected according to a rhombohedral network, Fig. 15.8. The bonding is mainly covalent, this conferring its thermomechanical properties. The center...
It decays via the weak nuclear force into a proton, an electron, and antineutrino, with a mean lifetime of about fifteen minutes. Free neutron decay is the prototype for nuclear beta decay and other semileptonic weak particle decays. The experimental value of the neutron mean lifetime gives ...