Run Series I

Table 4.2: Run summary for Series 1. For thin deuterium overlayers shown with , the nominal gas input values are given, but the actually thickness has some uncertainties (see Section 3.3.2). GMU, the number of ``good muons,'' is derived from Eq. 3.3. Data was collected typically at the rate of 3.5 to 4.0 GMU/s, i.e., 12-15 GMU/hour.

ID Run Target Upstream GMU ( )

I-1 1526 SET1 (1000 T $\cdot l$ H₂ with 0.1% T₂) 9.179

1527 SET1 47.377

1528 SET1 77.682

1529 SET1 102.109

subtotal 1526-29 304.094

I-2 1536 SET1 3 T $\cdot l$ 43.726

I-3 1538 SET1 6 (3+3) T $\cdot l$ 13.471

1539 SET1 6 (3+3) T $\cdot l$ 34.918

1540 SET1 6 (3+3) T $\cdot l$ 39.038

1541 SET1 6 (3+3) T $\cdot l$ 88.066

subtotal 1536-41 219.219

I-4 1542 SET1 12 (3+3+6) T $\cdot l$ 12.533

1543 SET1 12 (3+3+6) T $\cdot l$ 9.027

1544 SET1 12 (3+3+6) T $\cdot l$ 24.896

1545 SET1 12 (3+3+6) T $\cdot l$ 49.753

subtotal 1542-45 96.209

I-5 1546 SET1 24 (3+3+6+12) T $\cdot l$ 21.302

I-6 1547 SET1 36 (3+3+6+12+12) T $\cdot l$ 22.423

I-7 1555 SET3 (1000 T $\cdot l$ H₂ with 0.3% T₂) 6.671

1556 SET3 33.033

subtotal 1555-56 39.704

I-8 1572 1000 T $\cdot l$ H₂ 26.844

Run Series I was performed for three weeks in November and December 1993. After many months of work spent on target system modification to incorporate tritium compatibility, observing a clear peak built up within minutes after starting the first dt fusion run was quite exciting indeed.

Run Series I was a commissioning run for the new tritium target system, and much of the time was devoted to testing of various systems and establishing safe procedures of target handling. It was the first time that we observed an $\alpha$ particle from muon catalyzed dt fusion with high resolution. In addition, the emission of muonic tritium into vacuum was observed for the first time.

For this thesis, MWPC imaging data was analyzed to study muonic tritium emission, on which the atomic beam method is based. Shown in Table 4.2 is a summary of runs analyzed from this Series. The standard emission target, denoted SET1 (or SET3) consisted of a mixture of 1000 T $\cdot l$ pure protium with 0.1% (or 0.3%) of tritium. An additional layer of thin deuterium, called an overlayer, was sometimes deposited on top of the emission layer. Its thickness for this Series, however, had some uncertainty due to the effects of gas remaining in the transfer tube, as described in Section 3.3.2 (see Fig. 3.12(a)). Other than the thin overlayers, the average conversion factor for T $\cdot l$ is 3.2 $\mu$ gcm^-2 per T $\cdot l$ . With a T1 beam counter rate of /s GMU events were accumulated at the rate of 10-12 /hour. The scaler GMU (Fig. 3.19) suffered an occasional malfunction during this run, therefore GMU derived from Eq. 3.3 was used for normalization.