"Dead-time" reduction of the detection system of the Dubna Gas-filled Recoil Separator

1. "Dead-time" reduction of the detection system of the Dubna Gas-filled Recoil Separator V.G.Subbotin, Yu.S.Tsyganov, A.A.Voinov, A.M.Sukhov, A.N.Polyakov, S.N.Iliev Joint Institute for Nuclear Research, 141980 Dubna, Russia XXI International Symposium on Nuclear Electronics and Computing. Bulgaria, Varna, 10-17 September, 2007.

2. Layout of the Dubna gas-filled recoil separator (DQQ configuration)

4. Layout of the Dubna gas-filled recoil separator (DQQ configuration)

5. Si focal plane box of PIPS detectors 12 strips 40mm*10mm each in focal plane surrounded by 8 side detectors 40mm*40mm without position sensitivity and 3 additional detectors in “veto” mode Particals’ signals: EVRs, alpha-,FF Efficiency • 87% of 4p for a-particles • 100% of 4p for FF Resolution • 60 keV for focal plane detectors • 100 keV for side detectors • Dy = 0.9-1.9 mm for EVR-α correlations and 0.5-0.9 mm for EVR-SF

6. Block diagram of the measuring electronics (only one detector circuit is shown completely).

7. Diagram of the logic of the registration of nuclear reactions products at DGFRS

8. The new logical block KL-203 to control the work of ADCs

9. The new logical block was designed and tested in the test reaction natYb+ 48Ca (for example, 220Th with T10 μs). “Dead-time” of the modern registration system is 8 s. In the experiment 249Cf+ 48Ca three decay chains originating from the parent isotope 294118 were detected (the half-lives of all the nuclei are longer than about 1 ms). Further investigation of the region of superheavy nuclei, e.g, nuclides with Z=120 in the reaction 244Pu+ 58Fedefinitely requires applying of this system because of the short half-lives (~10-50 s) expected for the isotopes 298,299120. Summary

10. Thank you

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