Display the Experiment Proposals for S1008

Experiment: S1008

Halo Neutrons and the β-decay of 11Li

by the 8Pi group

Closed
Spokespersons:
F. Sarazin (Colorado School of Mines)

Original Proposal for EEC meeting 200407S

Table of Contents

Detailed Information


Beam Shift Summary

12-hr ShiftsBeam Line / channelPolarized Primary BeamPriority
New Beam Requests
 14 8pi @ ISAC No
Committee Recommendations
 4 No M
10 No H
10 shifts with high priority for A1 stopper; 4 shifts at medium priority on an alternate stopper.
Beam Shifts Used
 14 ISAC No
Used on Schedule 106.
Beam Shifts Remaining
 0 - No

Membership

F. Sarazin Colorado School of Mines Professor 40 % Spokesperson
C. Mattoon Colorado School of Mines Student (Graduate) 50 %  
A. Andreyev TRIUMF Research Associate 20 %  
A.C. Morton TRIUMF Research Associate 20 %  
C.J. Pearson TRIUMF Research Associate 20 %  
G. Ball TRIUMF Research Scientist 20 %  
J. Al-Khalili University of Surrey Professor 20 %  
M.B. Smith TRIUMF Research Associate 20 %  
S.C. Ravuri TRIUMF Research Scientist 20 %  
C. Andreoiu University of Guelph Research Associate 10 %  
C.E. Svensson University of Guelph Professor 10 %  
D.G. Melconian University of Washington Research Associate 10 %  
E.F. Zganjar University of Louisiana Professor 10 %  
G.F. Grinyer University of Guelph Student (Graduate) 10 %  
J. Waddington McMaster University Professor 10 %  
J.L. Wood Georgia Tech Professor 10 %  
J.R. Leslie Queen's University Professor Emeritus 10 %  
P.E. Garrett Lawrence Livermore National Laboratory Research Scientist 10 %  
P.M. Walker University of Surrey Professor 10 %  
W.D. Kulp Georgia Institute of Technology PDF 10 %  

Basic Information

Date Submitted
2006-07-12 15:32:43
Date Experiment Ready
2004-07-01
Projected Completion Date
2005-04-01
Summary *

This proposal is a follow-up of a previous study, made with less than a thousand 11Li per second beam. This experiment has yielded very exciting results (see text).

We propose to re-measure the β-decay of 11Li using the combination of the state-ofthe-art 8pi and Sceptar arrays, with the available enhanced 11Li yield available (44000 pps measured at the yield station with 40μA p+ beam on target). In recent experiments done at the 8pi, the 4π positron array Sceptar provided the detection of the β. It was shown that the use of β-γ coincidences provided a major clean-up of the γ-spectra, even for beams of only a few atoms per second. This capability is expected to improve very significantly the quality of the data, as described in this proposal.

The main objective of this measurement is, by mean of lineshape analysis, to look for weak branches in the β-delayed one-neutron emission to excited states in 10Be. In particular, a good statistics is required to determine the precise lineshape of the 5.96 MeV peak, which is crucial to resolve unanswered questions left from the first experiment.

A new experiment is also necessary to resolve the discrepancies observed between our present results and a recent work done at ISOLDE.

Plain Text Summary *
Primary Beam Line
ISAC-LE, 8 pi
Primary Beam and Target
Ta, 500 MeV, cw
Secondary Channel
ISAC-LE
Secondary Beam
11Li (unstable, 8.6 ms) 30-60 keV
TRIUMF Support (Resources Needed)
On-going development of a High-Power Ta target.
Other Funding

The funding of the Sceptar array was provided by NSERC. The 8pi maintenance, operation and upgrade is also funded by NSERC.

This work is supported in part by US DOE Grants/Contracts No: DE-FG03-93ER40789 (Colorado School of Mines), DE-FG02-96ER40959 (Georgia Tech) and W-7405-ENG-48 (University of California, Lawrence Livermore National Laboratory).

Safety Issues
No unusual safety hazards are associated with this experiment. Standard precautions will be taken with the detector high voltages, vacuum system, and the HPGe liquid nitrogen filling system.

Proposals and Progress Reports

200407S (Original Proposal)