Travis, Jason & Angus.	Oct 5th, 6th & 9th

The new ITMx has been welded and the violin modes of the fibres measured in air with the PUM clamped. The welding went quite smoothly apart from a couple of points. 
1)	The epoxy around the sapphire prism on one side of the PUM (+Y side) has charred due to heat from the welding of that fibre.
2)	The lengths of the horns on the PUM after fibre removal were not all exactly 6.0 mm above the ear, and this was not compensated for exactly with each fibre. The consequence is that the break-off values for one of the fibres (+X-Y) will be higher at the PUM and a bit lower at the ITM
The following fibres were used and the violin harmonics recorded

Posn	S/N		fund	2nd	3rd	4th	5th	(predicted in-vac)
+X+Y	S1400158 	502.45	994.8	1463.8	(1930)	[2390]	503.0
-X+Y	S1400137	503.96	997.85	1468.3	1931.6	(2391)	504.0
-X-Y    S1400164	504.71	1001.6	1472.4	1940.3	2408.3	504.6
+X-Y	S1400154	504.45	1002.6	1466.6	1936.4	2390.0	505.4

Accuracy is about +/- 0.05 for the fundamental, +/- 0.2 for the 2nd harmonic and the higher harmonics are generally +/- 0.5 or better, except for the ones in brackets which are worse. The round brackets are +/-1 and the square is +/-10 Hz (yes ten!).
It can be seen that the harmonics “cross” and that without this measurement it would be harder to determine which harmonic belongs to which fibre.
The pitch prediction from the fibre profiles was 0.1 mrad up (wrt PUM), the actual pitch is 0.3 mrad up. The roll and separation are as good as, or better than, the previous ITMx assembly. The yaw and pendulum frequencies were measured with +/- 0.005 Hz accuracy to 0.650 and 1.095 Hz respectively.
Attached are typical (linear) plots of the modes and a zip file of the original data files and excel files. Plus pics of the welds.
Fibre guards are on.