Eight tubes containing the alignment channels are housed inside inner cylinder of the TOB, from which the TIB is also supported with rails at phi=0 and phi=180.

The phi positions of such tubes are given below, in radians and degrees.

Table 1: Phi positions for the 8 alignment channels between TIB and TOB.

Channel #	phi position (rad)	phi position (deg)
1	( 7/112) * 2pi	22.5
2	( 23/112) * 2pi	73.92857
3	( 33/112) * 2pi	106.07143
4	( 49/112) * 2pi	157.5
5	( 65/112) * 2pi	208.92857
6	( 77/112) * 2pi	247.5
7	( 93/112) * 2pi	298.92857
8	(103/112) * 2pi	331.07143

The TOB is rotated so that one of the "low" rods is centred in phi=7/112 * 2pi (= 22.5 degrees). All the rays hit TOB detectors in the fiducial region.

In the TIB, the detectors of the outer half of the 4th layer are centred in 1/112 * 2pi, 3/112 * 2pi, 5/112 * 2pi .... 111/112 * 2pi, so all detectors are hit in the centre of their active area.