Technical Design Report Super Fragment Separator

DRAFT
Table 2.4.11: Mechanical properties of stainless steel 316LN.
Temperature Tensile strength Yield strength Elongation
σb (MPa) σ0.2(MPa) δ5 (%)
300 K ≥650 ≥350 ≥35
4 K ≥1500 ≥1000 ≥35
To reduce the heat flux to the helium system, the outer surface of the casing will be wrapped with a
multi-layer insulation. Figure 2.4.33 shows the cross section and the top view of the coil casing.
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Figure 2.4.33: Cross-section (left panel) and top view (right panel) of the coil casing.
The thermal shield has to have a good thermal conductivity, a good rigidity to weight ratio, and has
to be easy to fabricate and to assemble. The main part of the thermal shield consists of seven pieces:
inner shield in two pieces, outer shield in two pieces, upper shield, bottom shield and a piece for the
current leads box. All pieces are made of copper plates with 2 mm thickness. The forced-flow
cryogen for cooling the thermal shield is liquid nitrogen (LN) or cold helium gas to intercept
thermal radiation from the cryostat. The cooling pipes are made of 1 mm thick copper having a
rectangular shape with an outer dimension of (20 × 8) mm 2 . To reduce the heat flux to the helium
system, the outer surface of the thermal shield will be wrapped with an insulation of ten layers.
Figure 2.4.34 shows a sketch of the thermal shield.
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