Inverse Compton scattering of coherent synchrotron radiation in an energy recovery linac

Abstract

We propose inverse Compton scattering (ICS) of coherent synchrotron radiation (CSR) from a relativistic short electron bunch in energy recovery linacs (ERL) as a high-flux subpicosecond x-ray and -ray source. An advantage of the CSR scheme over a conventional ICS source is that no external laser is required, and synchronization between CSR pulses and electron bunches is obtained automatically. Moreover, higher-flux x rays can be generated from the ICS of CSR in an ERL operated at a high repetition rate, 100 MHz to 1.3 GHz. Using parameters of the Compact ERL at KEK, 1 Â 10 13-14 phs=s b.w. 10% (the number of photons pulse À1 bandwidth unit À1 ) x ray with a 100 fs-1 ps pulse duration can be obtained, for an energy range from 0.04 to 4 keV. In the case of a 5-GeV ERL, rays with energy around tens of MeV are generated with 1 Â 10 8 phs=pulse b.w. 10% at a repetition rate of several hundreds of MHz.

First determination of an astrophysical cross section with a bubble chamber: The N15(α,γ)Ugalde1, DiGiovine2, Henderson3 et al. 2013Physics Letters B141181View full textAdd to dashboardCite

“…The cross section obtained from the 19 F(γ,α) 15 N reaction converted to the 15 N(α,γ) 19 F scale using equation 1 is given by the solid points in Fig. 3.…”

“…The presented experimental data points have not been corrected for this background source as further beam profiling studies need to be performed. At an incident flux of 3×10 6 γ/s the background allowed us to set an upper limit on the cross section for the 15 N(α,γ) 19 F reaction at a level of 3 nb.…”

“…3 is the result of an R-matrix [13] calculation performed with the AZURE code [14]. We used the resonance parameters of the 19 F states in the E x =5-6 MeV range obtained from the direct 15 N(α,γ) 19 F measurement of [15] and folded the curve with the energy profile of the γ-ray spectrum (inset in Fig. 3).…”

“…This process is the last link in the thermonuclear reaction chain leading to the nucleosynthesis of fluorine in Asymptotic Giant Branch (AGB) and Wolf-Rayet stars [10]. The choice of reaction to study was determined by the existence of a strong J π =1/2 + resonance in 19 F at E x =5.337 MeV, which has been measured in direct (α,γ) experiments. C 4 F 10 was chosen as the fluorine containing liquid as it becomes superheated at room temperature and pressure.…”

“…For a proof of principle experiment we selected the 15 N(α,γ) 19 F reaction studied via the time inverse 19 F(γ,α) 15 N process. This process is the last link in the thermonuclear reaction chain leading to the nucleosynthesis of fluorine in Asymptotic Giant Branch (AGB) and Wolf-Rayet stars [10].…”