1. magnetic confinement - ENEA - Fusione

1. MAGNETIC CONFINEMENT
29
1.2 FTU Facilities
Fig. 1.22 - Schematic of
the boronisation plant.
FTU
VG1-1
IE
AD
AD
IE
VG1-2
F2
F2
F2
F2
VG1-3
AD
IE
AD
IE
VG1-4
FTU
FTU HALL
VG1-M
GAS PIPELINE
ABOUT 30 m
CABINET
IE1
FC
Al camino
NEUTRAL GAS MODULE
V0
V1
Bottle He
D1
Al camino
S1
CR1
VG1-1 = valve
VG1-2 = valve
VG1-3 = valve
VG1-4 = valve
VG1-M = valve
S2
GAS ACTIVE MODULE
CR2 V3
Vacuum
Pump
V2
MHP
V5
V4
F1
VB
V6
MBP
D2
MMP
Bottle
He (90%)+B 2 H 6 (10%)
F2 = filter a 0.2 µm
IE = electric break
IE1= electric break
FC = flux controller
[1.32] W.R. Baker et al.,
Vuoto, XXVIII, N. 3-4,
(1999)
[1.33] W. Braker and A.L.
Mossman, Matheson gas
data handbook, (Ed.
Matheson, 1980) pp. 219-
223
[1.34] W. Stopford and
W.B. Bunn, Effects of
exposure to toxic gases,
(Ed. Matheson, 1988) pp.
21-27
The FTU boronisation system was designed and installed by the Italian company
RIVOIRA on the basis of the previous experience at RFX [1.32]. Diborane is both
toxic and explosive and hence requires particular safety measures [1.33,1.34]. To
facilitate operation and improve safety, the whole system is equipped with its own
remote control and protection system.
The diborane system consists of the following main elements (fig. 1.22):
• A special gas cabinet for toxic gas mixtures, with its own exhaust system
comprising a gas extractor and a chemical filter to decompose diborane in the case of
accidental release.
• A chemical filter placed at the inlet of the rotary pump to evacuate the gas
immission lines from diborane at the end of boronisation.
• Pneumatic valves inside the gas cabinet, which are all operated with compressed
nitrogen to avoid the risk of sparks or fires.
• A diborane bottle with a remotely controlled pneumatic valve.
• A gas flux controller to regulate the gas-feed rate.