Status Report: McMaster UniversityFeb 1, 2013 to April 17, 2015

Balraj Singh Department of Physics and Astronomy

McMaster University(Retired June 30, 2013. On BNL contract since Oct 2013) (Infrastructure for the reported work still provided by McMaster U.)

IAEA-NSDD-2015IAEA-Vienna, April 20-24, 2015

Nuclear Structure and Decay Data

ENSDF evaluations; training

XUNDL compilation of current papers, coordination

NSR writing key-word abstracts of PR-C papers

Horizontal evaluations and compilations:

B(E2) for first 2+ states in e-e nuclei.

Beta-delayed neutron (BD-N) emitters: %Pn, T1/2

Compilation of nuclear isomers of T1/2 ≥ 10 ns

Some participation in collaborative experiments in nuclear structure

ENSDF: NSDD: McMaster Responsibility (25 A-chains)

A=31 (2013)A=32 (2011)A=33 (2011)A=34 (2012)A=35 (2011)A=36 (2011)A=37 (2012)A=38 (2008)A=39 (2006)A=40 (2004; update in progress) @A=41 (2001; update in progress) *A=42 (2001, updated: rev stage)A=43 (2001, updated: final version)A=44 (2011) @ With another center * At other center(s)

During 2013-15, work was also done on other A-chains and several nuclide updates, which are outside McMaster’s A-chain responsibility

A=1 (2005)

A=64 (2007)

A=89 (2013)

A=98 (2003; update in progress) @

A=100 (2008)

A=149 (2004)

A=151 (2009)

A=164 (2001, updated: in review)

A=188 (2002; update in progress) *

A=190 (2003); update in progress)

A=194 (2006)

ENSDF: A-chain Evaluations Published in NDS (Feb 1, 2013 to April 17, 2015)

A=31: C. Ouellet and B. Singh, NDS 114, 209-396 (2013)

A=211: B. Singh et al., NDS 114, 661-749 (2013): IAEA-ICTP workshop: 10 authors, 17 trainees.

A=75: A. Negret (*) and B. Singh, NDS 114, 841-1040 (2013)

A=215: B. Singh et al., NDS 114, 2023-2078 (2013): VECC-ENSDF workshop Kolkata, India : 9 authors, 13 trainees.

A=85: B. Singh and J. Chen, NDS 116, 1-162 (2014)

A=129: J. Timar (*), Z. Elekes (*) and B. Singh, NDS 121, 143-394 (2014)

A=86: A. Negret (*) and B. Singh, NDS 124, 1-156 (2015)

A=61: K. Zuber (*) and B. Singh, NDS 125, 1-200 (2015) * From European data center, visited McMaster for 2-3 weeks

Research/other publications during 2013-2015

1. Collective Structure in 94Zr and Subshell Effects in Shape Coexistence; A. Chakraborti et al.; Phys. Rev. Lett. 110, 022504 (2013) (From experiment at TRIUMF)

2. On an unverified nuclear decay and its role in the DAMA experiment:

J. Pradler, B. Singh, and I. Yavin; Phys. Lett. B 720, 399 (2013)

3. Reexamining the half-lives of 195Os and 195Ir: M. Birch, J. Flegenheimer, Z. Schaedig,

B. Singh, and M. Thoennessen: Phys. Rev. C 88, 067301 (2013)

4. Compilation of directly measured nuclear spins of ground states and Isomers:

A. MacDonald, B. Karamy, K. Setoodehnia, and B. Singh; NDS 114, 397 (2013).

5. First Compilation and Evaluation of Beta-Delayed Neutron Emission Probabilities and

Associated Half-Lives for A ≤ 72 Nuclei, M. Birch, B. Singh, D. Abriola, I. Dillmann,

T.D. Johnson, E.A. McCutchan, and A.A. Sonzogni, NDS 120, 66 (2014) (ND-2013)

6. Nuclear Science References Database; B. Pritychenko, E. Betak, B. Singh, and J. Totans;

NDS 120, 291 (2014) (ND-2013)7. B(E2) Evaluation for 0+

1 → 2+1 Transitions in Even-Even Nuclei:

B. Pritychenko, M. Birch, M. Horoi, and B. Singh: NDS 120, 112 (2014) (ND-2013)

8. In-beam γ-ray Spectroscopy of 30P via the 28Si(3He,pγ)30P Reaction (also XUNDL submission);

E. McNeice, K. Setoodehnia, B. Singh et al., NDS 120, 88 (2014) (ND-2013)

9. Method of Best Representation for Averages in Data Evaluation;

M. Birch and B. Singh; NDS 120, 106 (2014) (ND-2013)

ENSDF: A-chain Evaluations Submitted for NDS Feb 1, 2013 to April 17, 2015

A=215: submitted April 2013; published 2013

A=86: submitted Sept 2013; published 2015

A=76: B. Singh and A. Farhan (submitted August 2014) (pre-review stage)

A=224: S. Singh and B. Singh (submitted July 2014) (pre-review stage)

A=139: P.K. Joshi, B. Singh, S. Singh, A.K. Jain (submitted March 2014)

(review stage)

ENSDF: A-chain Evaluations in pipeline for NDS Feb 1, 2013 to April 17, 2015

A=42: J. Chen and B. Singh (final version for next NDS issue)

A=43: B. Singh and J. Chen (review stage)

A=164: B. Singh and J. Chen (review stage)

A=139: Review stage

A=76, 224: pre-review stage (soon to be submitted for review)

ENSDF: Nuclide evaluations and reviews Feb 1, 2013 to April 17, 2015

Other Nuclide Updates (not related to A-chain evaluation)

148 nuclides updated (by B. Singh) for ENSDF

Mostly far-off the stability New Nuclides and/or nuclides for which excited state and/or gamma-ray data became available for the first time.

Papers for these nuclides were generally not compiled for XUNDL database.

Reviews:

Two mass chains were reviewed for NDS publications.

Preliminary review was done for another mass chain; full review is in progress

One nuclide was reviewed for DDEP.

ENSDF: A-chain evaluations: in progress

A=40: with J. Chen (NSCL-MSU) (previous 2004)

A=57: with A. Negret (Bucharest) (previous: 1998)

A=98: with S. Basu and A. Chakraborti (*) (India) (previous: 2003)

A=130: with A. Rodionov (PNPI) (previous: 2001)

A=189: with T. Johnson (NNDC, BNL) (previous: 2003)

A=227: IAEA-ICTP, ENSDF workshop (March 2014) (previous: 2001)

A=79, 190, 165: (previous 2002, 2003, 2006)

(*): Anagha Chakraborti (Vishva-Bharati University, India) attended March 2014 IAEA-ICTP ENSDF workshop

ENSDF: visitors, training and workshop

Dr. A. Chakraborti (Vishva-Bharati Univ., India): visited McMaster for 4 weeks in summer 2013: mainly analysis of Zr-94 data from Y-94 decay collected in a 2011 experiment at TRIUMF.

Also learnt ENSDF formats and some procedures. Back home, he compiled several XUNDL datasets. Currently with S. Basu (VECC retiree in India) and myself he is working on update of A=98.

Dr. A. Rodionov (PNPI): visited McMaster for 2 weeks in summer 2013 to work on A=130, and other ENSDF-related matters.

Dr. S. Singh (MM-Univ., Mullana, India): visited McMaster for 5 weeks in summer 2014 to work on A=224 mass chain, and go through some ENSDF procedures. (This visit was not hosted by McMaster).

IAEA-ICTP, ENSDF Workshop: March 2014: I participated as a lecturer, and coordinated evaluation of A=227 mass chain. This work is in progress, close to its first submission

ENSDF: related codes

Attended ENSDF-Codes meeting at IAEA in August 2014

Proposed to write a new GAMUT-type code for gamma-ray energies

and intensities in Adopted datasets.

Discussed JAVA-NDS (?)

Alpha-radius code: with S. Singh

XUNDL: compilation of current literature Feb 1, 2013 to April 17, 2015

685 compiled datasets and 70 updated (for new papers from the same groups) datasets from 192 recent (2013- 2015) publications.

451 datasets from other centers were reviewed, and edited as needed

Continued correspondence, as needed, with the authors.

Training of a new undergraduate students in 2013, 2014

Compilation new mass measurements papers: Nov 2012 –Oct 2014: 30 primary papers (195 data points) available on M. Smith’s webpage: www.nuclearmasses.org

NSR: keyword abstracts of PRC articles (Feb 1, 2013 to April 17, 2015)

PRC issues: Oct 2012 to Dec 2014 (27 months):

Keyword abstracts written for about 1550 articles from

a total of ~2450.

Undergraduate students prepared first drafts for many articles:

M. Birch (*), E. Thiagalingam (*), E. McNeice (*), M. Walter

I provided training for the key-wording process. Draft of keywords

were checked and edited for technical content, wording, and run

through NSR-PREP code to resolve formatting errors, prior to sending

to NNDC

 (*): Until Dec 2013.

Horizontal evaluations: B(E2)

B(E2) for first 2+ states in e-e nuclei: update of Raman’s 2001 evaluation: NNDC(BNL) + McMaster + Central Michigan Univ. collaboration:

B. Pritychenko, J. Choquette, M. Horoi, B. Karamy and B. Singh, An update of B(E2) evaluation for 01+ to 21

+ transitions in even-even nuclei near N~Z~28,

ADNDT 98, 798-811 (2012).

Evaluated and compiled data for the entire mass region were prepared and submitted a paper to ADNDT journal in Dec 2013. Reviewer’s comments received May 2014.

Revised and updated version sent August 2014.

Still waiting for reviewer`s second set of comments after 8 months.

Preprint available on arXiv webpage.

We plan some further work using the compiled B(E2) database for above paper:

1.Investigate differences, if any, between different techniques of measuring B(E2), most common being Coul. Ex. and lifetime measurements.

2.Comparison of adopted B(E2) values with Grodzins formula.

B(E2) paper submitted to ADNDT (Dec 20, 2013; Aug 28, 2014).Continue to update for new papers as we wait for reviewer’s comments

Horizontal evaluations: Beta-delayed neutron decayM. Birch, B. Singh, D. Abriola, I. Dillmann, T. Johnson, E. McCutchan, A. Sonzogni

IAEA-CRP for creating a reference database for microscopic and macroscopic quantities for beta-delayed neutron precursors was approved in Sept 2012. First research coordination meeting (RCM) was held in August 2013. Second RCM was held March 23-27, 2015.

B. Singh attended both these meetings and presented progress reports of the compilation and evaluation work at McMaster.

Work on nuclei in Z=2-28 region has been completed. Paper was submitted for publication in NDS in Feb 2015.

Work involved: 219 β-n emitters in Z=2-28 region, 107 P1n values, 20 P2n,

5 P3n and 1 possible P4n (280 references from 1948 to 2015 consulted).

Collaboration:

M. Birch and B. Singh (McMaster): Selection of relevant nuclides. Search and collection of literature. Compilation and evaluation. First draft of paper

D. Abriola (CNEA, Argentina), I. Dillmann (TRIUMF), T. Johnson, E. McCutchan, and A. Sonzogni (NNDC, BNL): Detailed checking of data tables. Systematics plots, final draft of paper.

Beta-delayed neutron data evaluation (IAEA-CRP)

Paper submitted to NDS (in review)

Beta-delayed neutron data: Tables and Data Files (Z=2-28) sent to IAEA-NDS for reference database

a. Table of recommended half-life and Pn data file with complete

bibliography (list of references hyperlinked to NSR database)

b. Table of nuclides and Q-values for possible P1n, P2n, P3n precursors (based on AME-12)

c. Table of compiled data for P1n, P2n, P3n and half-lives with

all available references, including some secondary

publications.

d. Supplementary Table of comments for Pn and half-life

measurements. (Will be made available, but not published)

e.Above data exist in three .excel files (Q values for relevant nuclides, recommended Pn and half-lives, compiled data for Pn and half-lives) . These were sent to IAEA-NDS in February 2015 for setup of B-DN database; and revised files sent last week.

f.All papers used in this work made available on a shared webpage.

Beta-delayed neutron data: Z=29-57 and beyond

Work in progress to evaluate and compile Pn and half-lives for nuclei in Z=29-57 region, and for some higher Z region nuclei, currently being investigated at several laboratories.

Compilation/evaluation at McMaster, VECC, Kolkata and CIAE, Beijing. The work will be coordinated by McMaster.

Work involved is for ~400 nuclides; double of that for Z=2-28 region. Expected to be completed by Dec 2016.

Experimental delayed-neutron spectra available in literature are being digitized to make these available in EXFOR database.

Question:Why to bother about this work when Pn and T1/2 data are available elsewhere e.g. in ENSDF, NUBASE, NWC, ..?

Are Pn and half-life data consistently evaluated for all the β-n emitters ? For possible answer, see L. Mathieu et al., J. Instrumentation 7, P08029 (2012), where Pn values from NNDC, ENDF/B-VII.0, JENDL-2000, JEFF-3.1.1, Audi-2003, Pfeiffer-2002, TOI(1996), Rudstam-1993 have been compared for nuclei in the A=73-161 region, and found to differ significantly.

Example of a rather important nuclide in β-n measurements

Current ENSDF: Adopted Pn is quoted to 0.4%; value quoted from NUBASE.

In NUBASE , adopted Pn is from a priv. comm. some years back. Same value used in some recent experimental papers on this isotope citing data source as ENSDF or NUBASE.

Since the time we started this work, precision of 0.4% in Pn for this nuclide has been of concern as to how one achieves this sort of precision.

Finally, about a month back I picked up courage and wrote to the author of the priv. comm. (to NUBASE) to clarify the quoted low uncertainty.

Reply from author, March 31, 2015:

“All I can say is that the uncertainty given for the Pn ……is the same as the uncertainty of the raw counts for the beta-neutron coincidences.  Uncertainties in the beta counting efficiency, neutron counting efficiency, and coincidence efficiency would probably increase the uncertainty for the overall result. Thus I can not verify the uncertainty of the result. Thus I suggest you ignore this result in your analysis”.

Author’s reply implies that Pn value for this nuclide needs to be reconsidered in ENSDF, NUBASE and possibly elsewhere!

Compilation of Nuclear Isomers A.K. Jain, et al. submitted to NDS for publication: post-review stage

Collaborative Research projects

Zr-94 structure experiment at TRIUMF in Sept 2011S. Yates et al. (University of Kentucky)

Phonon-Coupled Excitations, mixed-Symmetry States, shape coexistence in Zr-94 through the study of Y-94 decay to Zr-94 at TRIUMF-ISAC facility using radioactive ion beam and 8π gamma-detector array

For Y-94 to Zr-94 decay, current data in ENSDF is from B. Singh et al., J. Phys. G: Nucl.

Phys. 2, 397 (1976) , where only 54 gamma rays reported with lowest intensity of 0.010%.

One paper from this work is published: A. Chakraborty et al., PRL 110, 022504 (2013).

In current work, evidence for ~450 gamma rays. We invited A. Chakraborty (from India)

at McMaster for 3 weeks in May-June 2013 for 3 weeks to extend the analysis further.

Also Rb-94 was a precursor in the above experiment, %Pn for decay of this nuclide will

Most likely be deduced from gamma-ray data in daughter nuclide.

.

Zr-98 structure: TRIUMF run in July 2013

S.W. Yates, P.E. Garrett, J.L. Wood et al.

Deformed Structures and Shape Coexistence in 98Zr through study of 98Y to 98Zr decay :

Experiment run at TRIUMF in July 2013 for 8 days.

My interest: I have been involved with A=98 ENSDF evaluation since 1992; and 2003-NDS for A=98 is currently being revised.

I participated in this experiment at TRIUMF. Data from this experiment are being analyzed at Guelph Univ. From analysis of gamma-ray data, we also expect to obtain Pn value for 98Y decay.

Structure studies of N=Z=15 nuclide 30P

28Si(3He, pγ)30P at University of Tsukuba Tandem Accelerator.

By product of an experiment on 30S for nuclear astrophysics.

Results were presented at ND-2013, and published briefly in the

proceedings: E. McNeice, K. Setoodehnia, B. Singh, A. A. Chen, J.

Chen et al. NDS 120, 88 (2014) .

XUNDL submission of detailed results in support of the above

publication prepared and archived in NSR; also available as a

compiled dataset in XUNDL database.

First measurement proposed by J. Stone and N. Stone to study angular distribution of beta-delayed neutrons and gamma rays from polarized sources at ISOLDE-CERN using NICOLE refrigerator and VANDLE neutron detector: partially approved Dec 2013. Experiment planned 2015

Thanks for your patience