Synchrotron radiation from positrons University of Maryand ：同步辐射从正电子马里兰大学

1、more phenomena difficult to observea mackinnonmore phenomena difficult to observe synchrotron radiation of positrons: sub-mm observations? inner bremsstrahlung of secondary neutronspositron energy distribution from + decayreally, this is what is injected into the source by colliding ps, s =2, tmax =

2、 3 gev/nucleffective distribution in thick target sourceedeesdtde)(/1de/dt : collisions (logarithmic energy dependence constant!) synchrotron (2) bremsstrahlung ( - above 100 mev)cumulative e+ distribution mean distribution in sourcedivide these by de/dtsynchrotron spectrum monoenergetic ec = 4.3106

3、 b 2 sinsynchrotron spectrum rough estimate 1032 protons above 300 mev 10-2 e+ per proton 410-22 1000 erg.s-1 .hz-1 10-2 s lifetimespread out over e.g. 100 s and divided by 4 au2 10-20 erg.cm-2.s-1 .hz-1 = 10-23 w.m-2.hz-1 = 10-1 s.f.u.too small inner bremsstrahlung spectrumknipp and uhlenbeck (1936

4、); bloch (1936); petrosian and ramaty (1972)angular distribution of ibxrscos2122zzrr = solar distancez = distance from earthdistances in aubriefly: x-ray flux integrates over all neutron energies present along the line of sight looking further from the sun samples more energetic neutrons because low

5、er energy ones decay approximately, the distribution of x-ray flux with angle is the laplace transform of the neutron energy distribution at the sun invert integral equation to deduce neutron energy distribution f(e)example3 . 3)10()( eefsuns x-ray haloseckel et al. (1992) modelled turbulent transport of cosmic rays in inner heliosphere + interaction with small-scale magnetic fields near solar surface (lots of assumptions!) predicted 2.310-8 neutrons.cm-2.s-1 above 100 mev at 1 au assume f(e)(e+10)- at the sun and normalise to this predictio