Disappearance of the N=14 shell

被引：24

作者：

Strongman, M. J. ^{[1
,2
]}

Spyrou, A. ^{[1
,2
]}

Hoffman, C. R. ^{[3
]}

Baumann, T. ^{[2
]}

Bazin, D. ^{[2
]}

Brown, J. ^{[4
]}

DeYoung, P. A. ^{[5
]}

Finck, J. E. ^{[6
]}

Frank, N. ^{[1
,2
]}

Mosby, S. ^{[1
,2
]}

Rogers, W. F. ^{[7
]}

Peaslee, G. F. ^{[5
]}

Peters, W. A. ^{[1
,2
]}

Schiller, A. ^{[2
]}

Tabor, S. L. ^{[3
]}

Thoennessen, M. ^{[1
,2
]}

机构：

[1] Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA

[2] Michigan State Univ, Natl Superconducting Cyclotron Lab, E Lansing, MI 48824 USA

[3] Florida State Univ, Dept Phys, Tallahassee, FL 32303 USA

[4] Wabash Coll, Dept Phys, Crawfordsville, IN 47933 USA

[5] Hope Coll, Dept Phys, Holland, MI 49423 USA

[6] Cent Michigan Univ, Dept Phys, Mt Pleasant, MI 48859 USA

[7] Westmont Coll, Dept Phys, Santa Barbara, CA 93108 USA

来源：

PHYSICAL REVIEW C | 2009年 / 80卷 / 02期

基金：

美国国家科学基金会;

关键词：

NUCLEAR; SPECTROSCOPY; DECAY; MODEL;

D O I：

10.1103/PhysRevC.80.021302

中图分类号：

O57 [原子核物理学、高能物理学];

学科分类号：

070202 ;

摘要：

An excited state of N-22 unbound with respect to neutron emission was observed in a stripping reaction from a 85 MeV/nucleon F-26 beam. The observed decay energy of 650(50) keV places the level, which is interpreted to be the first 3(-) state, at an excitation energy of 1.93(22) MeV. Together with the previously measured bound states of N-22, reduction of the N=14 shell gap compared to less neutron-rich nitrogen isotopes at the neutron dripline is observed. Based on the magnitude of the reduction of the shell gap for N-22, a disappearance of the gap and even a level inversion of the nu 1s(1/2) and the nu 0d(5/2) levels in the neutron-unbound nucleus C-21 seems likely.

引用

页数：4

共 25 条

[1] DECAY SCHEMES OF C-15,N-16, AND O-19 [J].

ALBURGER, DE ;

GALLMANN, A ;

WILKINSON, DH .

PHYSICAL REVIEW, 1959, 116 (04) :939-949

[2] Construction of a modular large-area neutron detector for the NSCL [J].

Baumann, T ;

Boike, J ;

Brown, J ;

Bullinger, M ;

Bychoswki, JP ;

Clark, S ;

Daum, K ;

DeYoung, PA ;

Evans, JV ;

Finck, J ;

Frank, N ;

Grant, A ;

Hinnefeld, J ;

Hitt, GW ;

Howes, RH ;

Isselhardt, B ;

Kemper, KW ;

Longacre, J ;

Lu, Y ;

Luther, B ;

Marley, ST ;

McCollum, D ;

McDonald, E ;

Onwuemene, U ;

Pancella, PV ;

Peaslee, GF ;

Peters, WA ;

Rajabali, M ;

Robertson, J ;

Rogers, WF ;

Tabor, SL ;

Thoennessen, M ;

Tryggestad, E ;

Turner, RE ;

VanWylen, PJ ;

Walker, N .

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, 2005, 543 (2-3) :517-527

[3]

Belleguic M, 2001, NUCL PHYS A, V682, p136C

[4] System testing and installation of the NHMFL/NSCL sweeper magnet [J].

Bird, MD ;

Kenney, SJ ;

Toth, J ;

Weijers, HW ;

DeKamp, JC ;

Thoennessen, M ;

Zeller, AF .

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, 2005, 15 (02) :1252-1254

[5]

Brown B.A., 2007, NUSHELL MSU

[6]

BROWN BA, 2009, COMMUNICATION

[7] Spectroscopic study of neutron shell closures via nucleon transfer in the near-dripline nucleus 23O [J].

Elekes, Z. ;

Dombradi, Zs. ;

Aoi, N. ;

Bishop, S. ;

Fulop, Zs. ;

Gibelin, J. ;

Gomi, T. ;

Hashimoto, Y. ;

Imai, N. ;

Iwasa, N. ;

Iwasaki, H. ;

Kalinka, G. ;

Kondo, Y. ;

Korsheninnikov, A. A. ;

Kurita, K. ;

Kurokawa, M. ;

Matsui, N. ;

Motobayashi, T. ;

Nakamura, T. ;

Nakao, T. ;

Nikolskii, E. Yu. ;

Ohnishi, T. K. ;

Okumura, T. ;

Ota, S. ;

Perera, A. ;

Saito, A. ;

Sakurai, H. ;

Satou, Y. ;

Sohler, D. ;

Sumikama, T. ;

Suzuki, D. ;

Suzuki, M. ;

Takeda, H. ;

Takeuchi, S. ;

Togano, Y. ;

Yanagisawa, Y. .

PHYSICAL REVIEW LETTERS, 2007, 98 (10)

[8] Nuclear data sheets for A=22 [J].

Firestone, RB .

NUCLEAR DATA SHEETS, 2005, 106 (01) :1-+

[9] Determination of the n=16 shell closure at the oxygen drip line [J].

Hoffman, C. R. ;

Baumann, T. ;

Bazin, D. ;

Brown, J. ;

Christian, G. ;

DeYoung, P. A. ;

Finck, J. E. ;

Frank, N. ;

Hinnefeld, J. ;

Howes, R. ;

Mears, P. ;

Mosby, E. ;

Mosby, S. ;

Reith, J. ;

Rizzo, B. ;

Rogers, W. F. ;

Peaslee, G. ;

Peters, W. A. ;

Schiller, A. ;

Scott, M. J. ;

Tabor, S. L. ;

Thoennessen, M. ;

Voss, P. J. ;

Williams, T. .

PHYSICAL REVIEW LETTERS, 2008, 100 (15)

[10] Evidence for a doubly magic 24O [J].