A high intense reactor based positron source

Slow-positron beamline temperature rise reduction at Kyoto University Research Reactor

“…However, there was no consensus on whether cadmium or gadolinium is advantageous in enhancing positron creation. Therefore, the KUR slow positron beamline adopted cadmium, which had already been proven in other reactor-based slow positron beamlines [5,9,10,18,19].…”

Analytical Methods Using a Positron Microprobe

“…28,29 The intensity of a 1-cm-diameter monoenergetic positron beam from an electron linear accelerator (LINAC) or a neutron reactor is typically 10 7 -10 8 e + /s, 29 whereas the intensity of a positron beam from an RI source is ~10 5 e + /s. By irradiating a tantalum (Ta) or W target with an electron beam of several tens of MeV, Bremsstrahlung X-rays are generated, which convert into electron-positron pairs.…”

Effect of neutron–photon converter materials (Cd, Gd, and Sm) on the positron production in a reactor-based slow positron beamline

“…An intense slow positron beam enables the use of positrons in advanced measurement techniques beyond conventional positron annihilation measurements, such as scanning positron microscopy [5,6,7,8,9] and total reflection highenergy positron diffraction [10,11,12]. Therefore, the operation and/or the new construction of intense slow positron beam facilities using nuclear reactors as a positron source are being promoted in many countries [13,14,15,16,17,18,19,20,21,22,23,24]. Experimental and simulation studies on positron moderation for a reactor-based positron source were also conducted [16,25].…”

“…Experimental and simulation studies on positron moderation for a reactor-based positron source were also conducted [16,25]. In reactor-based slow positron beamlines, a neutron-photon converter made of cadmium (Cd) is commonly used to improve the intensity of gamma-ray photons required for the positron pair production [13,14,15,16,17,18,19,20,21]. A reactor-based positron source containing a neutronphoton converter is exposed to an intense nuclear heating environment.…”