4.1 Aerogel outgassing

4 Materials

4.1 Aerogel outgassing

We have performed[7] a rapid decompression and outgassing test for the M.E.W. aerogel (SP-30) which is slightly less dense than the final aerogel. The index of refraction of the aerogel was 1.027 (density r=0.12 g/cm3). The rapid decompression was performed by decreasing the pressure in the chamber from 1 Atm. to 0.1 Atm. within 1 min. No visible change of the aerogel was observed.

Using the same vacuum chamber we performed an outgassing test. Figure 4-1 shows the variation of pressure as a function of time. The chamber volume was pumped by a primary pump at a rate of 150 Lt./s and a secondary pump at a rate 8 Lt./s.

A second outgassing test was performed using a primary pump. The sample (seven blocks of 11.35x11.35x1 cm3) were weighted before and after the outgassing test. The total mass loss was 0.90 gr, corresponding to a total outgassing mass loss of 0.8% of the total mass.

Figure 4-1 Outgassing of aerogel SP-30.

[7] in collaboration with M.Brouet, CERN

Issue: Draft - Revision: 04 - Last Modified: 20 April 1997