First Direct Measurements of Superheavy-Element Mass Numbers.

Autor:	Gates JM; Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA., Pang GK; Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA., Pore JL; Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA., Gregorich KE; Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA., Kwarsick JT; Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.; University of California, Berkeley, California 94720, USA., Savard G; Argonne National Laboratory, Argonne, Illinois 60439, USA.; University of Chicago, Chicago, Illinois 60637, USA., Esker NE; TRIUMF, Vancouver, British Columbia V6T 2A3, Canada., Kireeff Covo M; Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA., Mogannam MJ; Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA., Batchelder JC; University of California, Berkeley, California 94720, USA., Bleuel DL; Lawrence Livermore National Laboratory, Livermore, California 94550, USA., Clark RM; Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA., Crawford HL; Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA., Fallon P; Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA., Hubbard KK; Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.; University of California, Berkeley, California 94720, USA., Hurst AM; University of California, Berkeley, California 94720, USA., Kolaja IT; University of California, Berkeley, California 94720, USA., Macchiavelli AO; Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA., Morse C; Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA., Orford R; Argonne National Laboratory, Argonne, Illinois 60439, USA.; McGill University, Montreal, Québec H3A 0G4, Canada., Phair L; Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA., Stoyer MA; Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
Jazyk:	angličtina
Zdroj:	Physical review letters [Phys Rev Lett] 2018 Nov 30; Vol. 121 (22), pp. 222501.
DOI:	10.1103/PhysRevLett.121.222501
Abstrakt:	An experiment was performed at Lawrence Berkeley National Laboratory's 88-in. Cyclotron to determine the mass number of a superheavy element. The measurement resulted in the observation of two α-decay chains, produced via the ^{243}Am(^{48}Ca,xn)^{291-x}Mc reaction, that were separated by mass-to-charge ratio (A/q) and identified by the combined BGS+FIONA apparatus. One event occurred at A/q=284 and was assigned to ^{284}Nh (Z=113), the α-decay daughter of ^{288}Mc (Z=115), while the second occurred at A/q=288 and was assigned to ^{288}Mc. This experiment represents the first direct measurements of the mass numbers of superheavy elements, confirming previous (indirect) mass-number assignments.
Databáze:	MEDLINE
Externí odkaz: