Run Series II

Table 4.3: Run summary for Series 2 (part 1)

ID Run Target Target GMU

Upstream Downstream ( )

II-1 1625 SET1 (1000 T $\cdot l$ H₂ with 0.1% T₂) 20 T $\cdot l$ 51.882

II-2 1630 SET1 3 T $\cdot l$ 20 T $\cdot l$ 17.250

1631 SET1 3 T $\cdot l$ 20 T $\cdot l$ 31.073

subtotal 1530-31 48.323

II-3 1635 SET1 6 (3+3) T $\cdot l$ 20 T $\cdot l$ 50.392

II-4 1640 SET1 14 (3+3+8) T $\cdot l$ 20 T $\cdot l$ 33.483

II-5 1650 1000 T $\cdot l$ H₂ - 41.391

1654 1000 T $\cdot l$ H₂ - 43.501

subtotal 1530-31 84.892

II-6 1657 SET1 - 24.136

1658 SET1 - 38.082

subtotal 1530-31 62.218

II-7 1663 SET1 14 T $\cdot l$ - 39.791

1664 SET1 14 T $\cdot l$ - 20.926

subtotal 1663-64 60.717

II-8 1666 SET1 14 T $\cdot l$ 500 T $\cdot l$ H₂ 46.745

1667 SET1 14 T $\cdot l$ 500 T $\cdot l$ H₂ 8.073

subtotal 1666-67 54.818

II-9 1671 SET1 14 T $\cdot l$ 500 T $\cdot l$ H 3 T $\cdot l$ 57.561

1673 SET1 14 T $\cdot l$ 500 T $\cdot l$ H 3 T $\cdot l$ 46.514

1674 SET1 14 T $\cdot l$ 500 T $\cdot l$ H 3 T $\cdot l$ 32.627

1675 SET1 14 T $\cdot l$ 500 T $\cdot l$ H 3 T $\cdot l$ 57.345

1681 SET1 14 T $\cdot l$ 500 T $\cdot l$ H 3 T $\cdot l$ 38.143

1682 SET1 14 T $\cdot l$ 500 T $\cdot l$ H 3 T $\cdot l$ 81.813

1683 SET1 14 T $\cdot l$ 500 T $\cdot l$ H 3 T $\cdot l$ 54.574

1684 SET1 14 T $\cdot l$ 500 T $\cdot l$ H 3 T $\cdot l$ 41.567^*

1685 SET1 14 T $\cdot l$ 500 T $\cdot l$ H 3 T $\cdot l$ 29.243^*

1686 SET1 14 T $\cdot l$ 500 T $\cdot l$ H 3 T $\cdot l$ 30.421^*

subtotal 1671-86 469.808^*

II-10 1688 SET1 14 T $\cdot l$ 500 T $\cdot l$ H 6 (3+3) T $\cdot l$ 50.370^*

II-11 1690 SET1 14 T $\cdot l$ 500 T $\cdot l$ H 20 (3+3+8) T $\cdot l$ 54.109^*

Table 4.4: Run summary for Series 2 (part 2)

ID Run US Target DS Target GMU ( )

II-12 1708 SET2 (1000 T $\cdot l$ H₂ with 0.2% T₂) - 46.441

II-13 1709 SET2 14 T $\cdot l$ - 52.875

1711 SET2 14 T $\cdot l$ - 11.266

1712 SET2 14 T $\cdot l$ - 40.259

1713 SET2 14 T $\cdot l$ - 14.359

1714 SET2 14 T $\cdot l$ - 48.087

subtotal 1708-14 166.846

II-14 1719 SET2 14 T $\cdot l$ 3 T $\cdot l$ 58.499

1723 SET2 14 T $\cdot l$ 3 T $\cdot l$ 51.871

1728 SET2 14 T $\cdot l$ 3 T $\cdot l$ 37.135

1729 SET2 14 T $\cdot l$ 3 T $\cdot l$ 38.114

1730 SET2 14 T $\cdot l$ 3 T $\cdot l$ 10.839

subtotal 1719-30 196.458

II-15 1741 SET2 14 T $\cdot l$ 23 (3+20) T $\cdot l$ 51.847

1742 SET2 14 T $\cdot l$ 23 (3+20) T $\cdot l$ 7.385

subtotal 1741-42 59.232

II-16 1693 SET0.5 20 T $\cdot l$ - 22.602

1694 SET0.5 20 T $\cdot l$ - 70.664

subtotal 1694-95 93.266

Run Series II was our production run, where the measurement of $d\mu t$ molecular formation via time of flight was attempted. Improvements in the target system had been made after Series I. The gas diffuser was replaced with the one with sintered metal to ensure microscopic uniformity of the target film. The gas transfer tubing was modified to remove the problem of gas remaining in the transfer tube which had caused uncertainties in thin layer thicknesses. Target support foil spacing was reduced from 39 mm to 17.9 mm, in order to increase at the downstream reaction layer the number of $\mu t$ for energies 0.5-2 eV, at which the largest resonances were predicted. The MWPC imaging system, which would not have been as effective due to the smaller foil spacing, was replaced by another silicon detector. The z-dimension (beam direction) of both of 2000 mm² silicon detectors were collimated to 13.9 mm, to view only the inner side of the Au foils, where target films exist, with reasonable (i.e., non-grazing) angles.

Shown in Tables 4.3 and 4.4 is the run summary for Series 2. The standard emission targets with tritium concentration 0.1% (SET1) and 0.2% (SET2) were used with deuterium overlayers shown with in the table. The GMUs were taken from the GMU scalers, but the runs with (*) in the table (Run 1684-90) had a problem with an ADC affecting silicon detector normalization, which will be corrected in Section 8.1.2.

Apart from the data for TOF measurements of molecular formation, test data for new experiments were taken during this run, which resulted in new proposals. These include precision measurement of muonic atom scattering cross sections and direct measurement of the $\mu$ CF efficiency-limiting sticking probability.