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The C1 conditional status of the b1 and Azz experiments collaborations will be reviewed at Jefferson Lab on August 1, 2022.

Here is the conditional review panel Charge.

The Conditional Review Report can be found here: Final Report

Review Meeting

Date: August 1, 2022

Time: 12:45 pm EST

Room: F324-325 at CEBAF center

Remote connection: https://jlab-org.zoomgov.com/j/1618705690?pwd=SVFTVWcrQml2aU43azNTN0R0WTNhdz09

Committee: Chris Keith (chair), Josh Pierce, Rolf Ent


12:45 - 1:00: Executive session

1:00 - 1:10: Intro/Overview, K. Slifer (10) (pdf)

1:10 - 1:50: Discussions of the charges Pt. I, (Charges 1,2,3,4), D. Keller (30+10)(pdf)

1:50 - 2:00: Coffee break

2:00 - 2:40: Discussions of the charges Pt. II, (Charges 2,3), E. Long (30+10) (pdf) (pptx) (Related T20 technote)

2:40 - 2:55: Summary, S. N. Santiesteban (15) (pdf)

2:55 - 3:00: Coffee break

3:00 - 4:00: Open discussion

4:00 - 5:00: Executive session

5:00: Closeout

Below we briefly summarize the progress that has been made in addressing the conditional status.

Progress in Tensor Enhancement

Figure 1. (Left) NMR spectra after ss-RF and target rotation resulting in a tensor polarization of 36.5+-3.5%. (Right) Vector and tensor polarizations with respect to the dose in beam. The vertical line indicates when annealing will be performed in the target.

The b1 and Azz experiments were C1 conditionally approved by PACs 41&44, respectively, with the requirement that: "a tensor polarization of at least (close to) 30% be achieved and reliably demonstrated under experimental conditions." Links to the PAC reviews are provided below. Our collaboration has recently demonstrated that a tensor polarization of at least 30% will be achieved under experimental conditions. So we request Jefferson Lab to fully approve these two experiments.

The details supporting our request to remove the C1 conditionals are available here.

As a brief summary, the left panel of the figure above shows tensor enhancement using the technique of semi-saturating RF (ss-RF) with continuous rotation of the target material. The points corresponds to the measured NMR data and the red line is the lineshape fit of the NMR spectra. This fit was used to extract the tensor polarization value of 36+-3.5%. The full lineshape is composed of the magnetic sublevel transitions m=1 → 0 (Blue) and m=0 → -1 (pink) lines. The right panel of the figure shows the predicted vector and tensor enhanced polarizations as a function of accumulated dose during experimental conditions. The vertical dotted line indicates the dose at which an anneal will be performed in order to keep the overall tensor polarization at 30%. Full details for these plots and supporting documentation is provided in the links on this wikipage.

Recent Tensor Enhancement Papers by the Collaboration

Modeling alignment enhancement for solid polarized targets Eur. Phys. J. A 53, 155 (2017) (arXiv)
Enhanced tensor polarization in solid-state targets NIM A 981, 164504 (2020) (arXiv)

Experiment Information

Experiment Scientific Rate PAC Decision PAC Results
The Deuteron Tensor Structure Function b1 (pdf) A- C1 link
Measurements of the Quasi-Elastic and Elastic Deuteron Tensor Asymmetries (pdf) A- C1 link