First Direct Measurements of Superheavy-Element Mass Numbers

被引：39

作者：

Gates, J. M. ^{[1
]}

Pang, G. K. ^{[1
]}

Pore, J. L. ^{[1
]}

Gregorich, K. E. ^{[1
]}

Kwarsick, J. T. ^{[1
,2
]}

Savard, G. ^{[3
,4
]}

Esker, N. E. ^{[5
]}

Covo, M. Kireeff ^{[1
]}

Mogannam, M. J. ^{[1
]}

Batchelder, J. C. ^{[2
]}

Bleuel, D. L. ^{[6
]}

Clark, R. M. ^{[1
]}

Crawford, H. L. ^{[1
]}

Fallon, P. ^{[1
]}

Hubbard, K. K. ^{[1
,2
]}

Hurst, A. M. ^{[2
]}

Kolaja, I. T. ^{[2
]}

Macchiavelli, A. O. ^{[1
]}

Morse, C. ^{[1
]}

Orford, R. ^{[3
,7
]}

Phair, L. ^{[1
]}

Stoyer, M. A. ^{[6
]}

机构：

[1] Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA

[2] Univ Calif Berkeley, Berkeley, CA 94720 USA

[3] Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA

[4] Univ Chicago, Chicago, IL 60637 USA

[5] TRIUMF, Vancouver, BC V6T 2A3, Canada

[6] Lawrence Livermore Natl Lab, Livermore, CA 94550 USA

[7] McGill Univ, Montreal, PQ H3A 0G4, Canada

来源：

PHYSICAL REVIEW LETTERS | 2018年 / 121卷 / 22期

关键词：

SPECTROMETER;

D O I：

10.1103/PhysRevLett.121.222501

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

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 alpha-decay chains, produced via the Am-243(Ca-48,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 alpha-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.

引用

页数：6

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