Complete reconstruction of Compton scattering in Camera by measuring 3-D track of recoil electron in gas Time Projection Chamber (TPC). TPC measure the 3-D imformation of the recoil electron track, and Scintillators arrays measure the scattering gamma-ray. The blue arrowed line indicate the gamma-ray, and the read curved line is recoil electron.


The schematic diagram of ETCC.


“2 Angles” of incident gamma direction focus gamma rays to NOT “circles” as by conventional Compton Camera BUT “a point “ similar to Optical camera. Real data of well-defined Point Spread Function as the diagrams below indicates.

These figures draw a comparison between Conventional Compton reconstruction method (left) and Electron Tracking method (right). Electron tracking method can determin the recoil electron direction, we get the clear gamma-ray image with no ghost.


Then, ETCC provides a well-defined Point Spread Function similar to Optical Telescope. Also Strong rejection ability of all background radiations by energy loss rate of tracks in gas-TPC.

The below figue show the ARM distribution. The background events accumulate in the positive side in histogram.

Real data of ARM distribution with no background.