2019/01/22 (Wednesday)
| 1100 | De-install NaI detectors from fridge shield. De-install all but the West shield wall and large lead source shield. |
|---|---|
| 1230 | Set NaI detectors on metal cart and locate them near the cryostat, directly opposite the standard PuBe source location. |
 |  |
| 1240 | Remove PuBe source from PAN 443 and place in standard position in PAN 43, near the West wall behind the large lead shield. |
|---|---|
| 1245 | Take a NaI spectra in (some of) the following configurations. |
| Configuration | Shielding | PuBe | NaI |
|---|---|---|---|
| 1_PuBe | Full | At W wall (standard) | On S wall (standard) |
| 1_bkg | Full | No | On S wall (standard) |
| 2_PuBe | Full | At S wall | On S wall (standard) |
| 3_PuBe | W wall and Pb pile | At W wall (standard) | Directly E of cryostat, heights of 40 cm (NaIC) and 107 cm (NaIB) |
| 3_bkg | W wall and Pb pile | No | Directly E of cryostat, heights of 40 cm (NaIC) and 107 cm (NaIB) |
| 4_PuBe | Pb pile | At W wall (standard) | Directly E of cryostat, heights of 40 cm (NaIC) and 107 cm (NaIB) |
| 4_bkg | Pb pile | No | Directly E of cryostat, heights of 40 cm (NaIC) and 107 cm (NaIB) |
| 5_PuBe | Pb pile | At W wall (standard) | Directly E of Pb pile, height 74 cm (NaIB) |
| 5_bkg | Pb pile | No | Directly E of Pb pile, height 74 cm (NaIB) |
| 6_PuBe | Pb pile | At W wall (standard) | Directly E of Pb pile, height 47 cm (NaIB) |
| 6_bkg | Pb pile | No | Directly E of Pb pile, height 47 cm (NaIB) |
| 6_PuBe | Pb pile | At W wall (standard) | Directly E of Pb pile, height 47 cm (NaIB) |
| 7_PuBe | Pb pile | At W wall (standard) | Directly E of Pb pile, height 12 cm (NaIB) |
| Configuration 3 | |
|---|---|
 |  |
| Configuration 3 | |
|---|---|
| Same as above, shield wall removed |  |
| Configuration 5 | |
|---|---|
 |  |
| Configuration 6 | |
|---|---|
 |  |
| Configuration 7 | |
|---|---|
 |  |
| Configurations 5,6,7 |
|---|
 |
In all of the above tests, the 4.4 MeV direct gamma was only observed when the NaI detector had a direct line of sight below the large Pb pile to to the PuBe source. This indicates that there is little to no gamma flux at the CDMS HV detector directly from the PuBe source (i.e through a crack in the Pb pile.) The PuBe presence does add a flat gamma continuum above background levels from roughly 3-7 MeV, but there is no dominating peaks in this region.