Search results for "strah"
showing 10 items of 123 documents
Die zirkulare Polarisation der inneren Bremsstrahlung beim K-Einfang von A37
1958
The circular polarization of the internal bremsstrahlung was measured for various photon energies by scattering on magnetized iron. In the spectral range investigated, complete polarization was found within the measuring error. An average value of P/sub c/ = +1.03 plus or minus 0.04 was obtained. This shows that the maximum parity violation occurs also in K-capture. (tr-auth)
A BeppoSAX study of the Galactic Z-source GX 340+0
2004
Abstract We present the results of a BeppoSAX broad band (0.1–200 keV) observation of the Z-source GX 340+0. The 1.8–30 keV continuum is well described by a blackbody ( kT BB ∼0.5 keV) plus a Comptonized component with seed photons temperature ∼ 1 keV and electron temperature ∼ 3 keV. A hard tail dominates the spectrum above 30 keV. It can be fitted using a bremsstrahlung component or, equivalently, a powerlaw (with a low-energy cutoff). We detect also a Gaussian line at ∼6.8 keV and an absorption edge at ∼9.2 keV. A low-energy (∼1 keV) unresolved feature needs further investigations.
Experimental study of the halo nucleusHe6using theLi6(γ,π+)He6reaction
2007
The reaction $^{6}\mathrm{Li}$($\ensuremath{\gamma},{\ensuremath{\pi}}^{+})$$^{6}\mathrm{He}$ was studied over the angular range ${\ensuremath{\theta}}_{\ensuremath{\pi}}=40$--150$\ifmmode^\circ\else\textdegree\fi{}$ with the aim of investigating the halo structure of $^{6}\mathrm{He}$. Photons from a bremsstrahlung beam were tagged in the energy range ${E}_{\ensuremath{\gamma}}=170$--220 MeV at a resolution of $\ensuremath{\Delta}{E}_{\ensuremath{\gamma}}=630$ keV, and positively charged pions detected using high resolution stacked HpGe detectors. The measured angular distributions for the resolved $^{6}\mathrm{He}$ ground and 1.80 MeV excited states are compared to previous measurements a…
New experimental method for investigation of the nucleon polarizabilities
2010
Abstract At the continuous wave (cw) Superconducting Darmstadt Electron Linear Accelerator S-DALINAC, a new method has been developed for the determination of the electric ( α ¯ ) and magnetic ( β ¯ ) polarizabilities of the proton and the deuteron. For that purpose the energy and angular dependence of the differential cross-section for elastic γ p and γ d scattering of bremsstrahlung photons in the energy range between 20 and 100 MeV is measured by detecting the recoiling proton (deuteron) in coincidence with the scattered bremsstrahlung photon. α ¯ and β ¯ are then found by means of a best fit to a theoretical description of the scattering cross-section with these quantities as open param…
Messung der zirkularen Polarisation der inneren und �u�eren Bremsstrahlung
1961
The polarisation of the internal bremsstrahlung γ's was detected by the Compton-forward-scattering with polarised electrons for three differentβ-decays: 1. for the allowed transition (P32), 2. for the unique forbidden transition (Sr90+Y90), and 3. for the forbidden transition with forbidden spectrum (Bi210=RaE). The detected polarisation values of P32 and (Sr90+Y90) agree with the theoretical values for the allowed transitions. The detected polarisation values for Bi210 are smaller than the theoretical values of the allowedβ-transition by a factor of 0.62±0.08.
Channeling experiments with sub-GeV electrons in flat silicon single crystals
2015
Abstract Various planar channeling experiments, performed at the Mainz Microtron MAMI with electrons at silicon single crystals, have been reanalyzed. Two types of signals have been employed. The low energy loss signal originates from emission of channeling radiation in the energy domain between 0.4 and 9 MeV while the high energy loss signal from electrons which have lost about 50% of their primary energy by emission of bremsstrahlung photons. The (1 1 0) planar channeling data, taken at a beam energy of 855 MeV with the former signal, can well be described on the basis of the solution of the classical Fokker–Planck equation. The measurements with the latter signal at beam energies between…
Angular distribution of scattered electrons associated with collimated bremsstrahlung and the tagging technique
2009
Abstract We investigate the angular correlation between a bremsstrahlung photon and its corresponding post-bremsstrahlung electron within the context of a magnetic tagging spectrometer with the aim of improving the instrument's efficiency. Our results are given in terms of angular distributions of the post-bremsstrahlung electron associated with photons that pass through a circular collimator centered in the forward direction. We start from the fully differential Bethe–Heitler (first Born approximation) cross-section, including the Moliere screening correction, which is then integrated over the photon azimuthal angle and over the photon polar angle defined by the collimator. These integrati…
Angular distribution of coherent bremsstrahlung
2012
The angular distribution of the linearly polarised photon beam produced by coherent bremsstrahlung from an aligned diamond radiator has been measured at the MAMI A2 tagged photon facility. The measurements were made with a prototype position sensitive photon detector which utilises the pair production process and a double sided silicon strip detector. This polarised photon beam is used for nuclear and hadronic experiments and in their analysis the polarisation is obtained from a calculation, which matches the experimental intensity spectrum. As the polarisation is related to the photon beam angular distribution, the present measurements can be used to test this calculation. The overall agre…
Virtual versus real nuclear Compton scattering in the Delta(1232) region
1996
[EN] In this paper we calculate the cross section for Virtual Compton Scattering off nuclei in the delta resonance region. We also calculate the background for the process from Coherent Bremsstrahlung in nuclei and explore the regions where the Virtual Compton Scattering cross section dominates. The study also shows that it is possible to extract the cross section for Real Compton Scattering from the Virtual Compton one in a wide range of scattering angles.
Determination of the total photo-absorption cross section of 197Au from () reaction cross sections
1984
Abstract Cross sections for the reactions 197Au ( γ, ℩ n ) (x ⩽ 12) have been measured for bremsstrahlung end-point energies in the range 60–340 MeV. From these dominant cross sections, the total photon absorption cross section is determined using a cascade-evaporation calculation to account for the missing reaction channels. The enhancement factor for the classical E1 sum rule is found to be 0.93 ± 0.10.