Seismic experiments

HNS/Teflon Explosive Charges For The Apollo 17 Seismic Experiment, LSPE , NOLTR 73-44... 

Hexanitrostilbene or HNS (C14H6N6012) is a heat-resistant yellow crystalline solid explosive. HNS is also resistant to radiation, insensitive to electric sparks, and less sensitive to impact than tetryl. It is used in heat-resistant booster explosives and has been used in stage separations in space rockets and for seismic experiments on the moon. Its melting temperature is 316 °C.12... 

Hexanitroshlbene (HNS) has been reported for use in achieving stage separation in space rockets and also as a component of heat-resistant compositions employed in the Apollo spaceship and for seismic experiments on the moon [107]. Similar to HNS, 3,3 -diamino-2,2, 4,4, 6,6 -hexanitrodiphenyl (DIPAM) has also been reported for such applications [108]. 

Diamino-2,2, 4,4 6,6 -hexanitrodiphenyl (DIPAM) [Structure (2.30)] is extremely insensitive to electrostatic discharge, requiring more than 32 kj for initiation. In addition, it has good thermal stability (m.p. ca. 304 °C) and has been used to achieve stage separation in space rockets and for seismic experiments on the moon in a manner similar to HNS [74]. 

The literature suggests that thermally stable explosives such as HNS were employed for seismic experiments on the moon [61]. This is probably due to safety considerations while handling explosives for such applications on the lunar surface. 

In supersonic missiles where warheads are subjected to aerodynamic heating, conventional explosives cannot be used and thermally stable explosives like TATB, TACOT, HNS and PYX, etc. are necessary for such systems. Some formulations based on these explosives are HNS/Kel-F800 95/5 (developed by Atomic Weapons Research Establishment, Aldermaston, UK) and AFX 521 (PYX/Kel-F800 95/5 — developed by Los Alamos National Laboratory, USA). Their shock sensitivities lie in the region required for boosters. HNS/Teflon explosive charges have also been used for the Apollo 17 seismic experiments [199]. 

Kilmer, E.E. (1973) HNS/teflon explosive charges for the Apollo 17 seismic experiments. LSPE, Naval Ordnance Laboratory TR No.73-44. 

HMX-based PBXs were developed for projectiles and lunar seismic experiments during the 1960s and early 1970s using Teflon (polytetra-fluoroethylene) as the binder. PBXs based on RDX and RDX/PETN have also been developed and are known as Semtex. Development is continuing in this area to produce PBXs which contain polymers that are energetic and will contribute to the explosive performance of the... 

HNS is used in heat-resistant booster explosives and has been used in the stage separation in space rockets and for seismic experiments on the moon. 

The evidence from seismic experiments is fully in agreement with the model outlined above. In the Fra Mauro region of Oceanus Procellarum the crust is about 65 km thick and overlies a solid mantle 126 The crust, in turn, is divided into two parts covered with a thin regolith. For comparison with the returned lunar samples, the upper layer has been inferred to be mare basalt and the lower one anorthositic gabbros. 

The Kaapvaal Project was vmdertaken to study the formation, stabilization and evolution of cratons, and to image the deep structure of the tectosphere (Carlson et al. 1996) (see also http // www.ciw.edu/kaapvaal for participants and a description of the project). A cornerstone of the Kaapvaal Project was a large-scale broadband seismic experiment designed specifically for geo-logical-scale imaging of the crust and upper mantle beneath the cratons and adjacent Proterozoic provinces of southern Africa (Fig. 1). The... 

Results to date from the southern Africa seismic experiment, including the surface-wave results cited above, fail to reveal a low-velocity asthenospheric layer beneath the Archaean keel. This result is particularly relevant in light of studies published by Qiu et al. (1996) and modified by Priestley (1999), which fit surface wave-... 

Webb, S. J., James, D. E. Nguuri, T. 1999. The integration of gravity data with seismological results from the Kaapvaal Craton Seismic Experiment an assessment of isostatic balance. In 6th Biennial Conference of the South African Geological Association. South African Council on Geosciences, Cape Town, 1-6. 

TABLE 17. SOME SEISMIC EXPERIENCE BASED METHODS... 

SENIOR SEISMIC REVIEW AND ADVISORY PANEL, Use of Seismic Experience and Test Data to Show Ruggedness of Equipment in Nuclear Power Plants, Rev. 4.0, SSRAP, Washington, DC (1991). 

Human-made sources or active sources are used in many seismic smdies of volcanoes. The first experiments of three-dimensional active-source investigations of volcanoes were made in two relict calderas located in the Cascade Range, western USA. One of them is the potentially active Newberry shield volcano with the caldera of 8 km diameter. In the active seismic experiment, Achaer et al. (1988) used three chemical explosions and a dense receiver network covering the caldera. They obtained a rather clear... 

Relay functionality using seismic experience data base is not acceptably demonstrated. 

The MRS pumps and supports have been seismically qualified by means of an engineering walkdown inspection, and comparison with a seismic experience data base (Reference 71). 

---