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Title: First Direct Measurements of Superheavy-Element Mass Numbers

Abstract

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 243Am( 48Ca,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 284Nh (Z=113), the α-decay daughter of 288Mc (Z=115), while the second occurred at A/q = 288 and was assigned to 288Mc. In conclusion, this experiment represents the first direct measurements of the mass numbers of superheavy elements, confirming previous (indirect) mass-number assignments.

Authors:
 [1];  [1];  [1];  [1];  [2];  [3];  [4];  [1];  [1];  [5];  [6];  [1];  [1];  [1];  [2];  [5];  [5];  [1];  [1];  [7] more »;  [1];  [6] « less
  1. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
  2. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States)
  3. Argonne National Lab. (ANL), Argonne, IL (United States); Univ. of Chicago, Chicago, IL (United States)
  4. TRIUMF, Vancouver, BC (Canada)
  5. Univ. of California, Berkeley, CA (United States)
  6. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
  7. Argonne National Lab. (ANL), Argonne, IL (United States); McGill Univ., Montreal, QC (Canada)
Publication Date:
Research Org.:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26)
OSTI Identifier:
1492331
Alternate Identifier(s):
OSTI ID: 1483716
Grant/Contract Number:  
AC02-05CH11231; AC02-06CH11357; AC52-07NA27344
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Physical Review Letters
Additional Journal Information:
Journal Volume: 121; Journal Issue: 22; Journal ID: ISSN 0031-9007
Publisher:
American Physical Society (APS)
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS

Citation Formats

Gates, J. M., Pang, G. K., Pore, J. L., Gregorich, K. E., Kwarsick, J. T., Savard, G., Esker, N. E., Covo, M. Kireeff, Mogannam, M. J., Batchelder, J. C., Bleuel, D. L., Clark, R. M., Crawford, H. L., Fallon, P., Hubbard, K. K., Hurst, A. M., Kolaja, I. T., Macchiavelli, A. O., Morse, C., Orford, R., Phair, L., and Stoyer, M. A.. First Direct Measurements of Superheavy-Element Mass Numbers. United States: N. p., 2018. Web. doi:10.1103/PhysRevLett.121.222501.
Gates, J. M., Pang, G. K., Pore, J. L., Gregorich, K. E., Kwarsick, J. T., Savard, G., Esker, N. E., Covo, M. Kireeff, Mogannam, M. J., Batchelder, J. C., Bleuel, D. L., Clark, R. M., Crawford, H. L., Fallon, P., Hubbard, K. K., Hurst, A. M., Kolaja, I. T., Macchiavelli, A. O., Morse, C., Orford, R., Phair, L., & Stoyer, M. A.. First Direct Measurements of Superheavy-Element Mass Numbers. United States. doi:10.1103/PhysRevLett.121.222501.
Gates, J. M., Pang, G. K., Pore, J. L., Gregorich, K. E., Kwarsick, J. T., Savard, G., Esker, N. E., Covo, M. Kireeff, Mogannam, M. J., Batchelder, J. C., Bleuel, D. L., Clark, R. M., Crawford, H. L., Fallon, P., Hubbard, K. K., Hurst, A. M., Kolaja, I. T., Macchiavelli, A. O., Morse, C., Orford, R., Phair, L., and Stoyer, M. A.. Wed . "First Direct Measurements of Superheavy-Element Mass Numbers". United States. doi:10.1103/PhysRevLett.121.222501.
@article{osti_1492331,
title = {First Direct Measurements of Superheavy-Element Mass Numbers},
author = {Gates, J. M. and Pang, G. K. and Pore, J. L. and Gregorich, K. E. and Kwarsick, J. T. and Savard, G. and Esker, N. E. and Covo, M. Kireeff and Mogannam, M. J. and Batchelder, J. C. and Bleuel, D. L. and Clark, R. M. and Crawford, H. L. and Fallon, P. and Hubbard, K. K. and Hurst, A. M. and Kolaja, I. T. and Macchiavelli, A. O. and Morse, C. and Orford, R. and Phair, L. and Stoyer, M. A.},
abstractNote = {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 243Am(48Ca,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 284Nh (Z=113), the α-decay daughter of 288Mc (Z=115), while the second occurred at A/q = 288 and was assigned to 288Mc. In conclusion, this experiment represents the first direct measurements of the mass numbers of superheavy elements, confirming previous (indirect) mass-number assignments.},
doi = {10.1103/PhysRevLett.121.222501},
journal = {Physical Review Letters},
issn = {0031-9007},
number = 22,
volume = 121,
place = {United States},
year = {2018},
month = {11}
}

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