Slits

The entrance slits ENS_I and ENS_O, and exit slit vertical selectors EXSY_I and EXSY_O have their openings arranged as shown in Fig. 3.21. The exit slit openings as a function of micrometer settings are shown in Table 3.2 and Fig. 3.26 for the inboard (X1A2) and outboard (X1A1) branches respectively. The file /mnt/x1a/slitsettings.dat should contain more exact values for the slit positions.

If for some reason the motor step positions are completely lost, you should know of the following:

ENS_O: the 200 $\mu$m is close to being aligned to the beam when you have a micrometer reading of 62.1 mm in a measurement as shown in Fig. 3.22.

EXSY_O: the 200 $\mu$m is close to being aligned to the beam when you have a micrometer reading of 37.9 mm in a measurement as shown in Fig. 3.23.

ENS_I: the 200 $\mu$m is close to being aligned to the beam when you have a micrometer reading of XXX mm in a measurement as shown in Fig. 3.22.

EXSY_I: the 200 $\mu$m is close to being aligned to the beam when you have a micrometer reading of XXX mm in a measurement as shown in Fig. 3.23.

Figure 3.21: Arrangement of slits ENS_I, ENS_O, EXSY_I, and EXSY_O.

Table 3.2: Inboard (X1A2) exit slit EXS_I calibration.

Slit $\mu$m	Dial mm	EXS_I step
5	4.99	4989
10	4.90	4857
15	4.81	4755
20	4.72	4669
25	4.64	4593
30	4.56	4525
35	4.49	4462
40	4.44	4403
50	4.30	4296
60	4.18	4199
80	4.01	4027
100	3.86	3876
125	3.70	3707
150	3.55	3554
175	3.42	3414
200	3.29	3282
300	2.84	2827
400	2.44	2442

Table 3.3: Approximate motor positions for entrance and vertical exit slit settings. The exact position should be within about 1500 steps of the value shown. In addition, the file /mnt/x1a/slitsettings.dat should contain more exact values for the slit positions.

Size	ENS_O	EXSY_O	EXS_O	ENS_I	EXSY_I	EXS_I	EXS_IH	EXSY_IH
10 $\mu$m	31200	31200	16900	6000	6000	4857	9950	11075
25 $\mu$m	26000	26000	16750	11200	11200	4593	15170	16275
40 $\mu$m	20800	20800	16600	16400	16400	4403	20380	21475
70 $\mu$m	15600	15600	16300	21600	21600	4110	25600	26675
120 $\mu$m	10400	10400	15800	26800	26800	3739	30800	31875
200 $\mu$m	5200	5200	15000	32000	32000	3282	36000	NO USE
Open	0	0	NA	37200	37200	NA	40000	39500

Figure 3.22: Measurement method for ENS_O 200 $\mu$m slit position. The same method is used for ENS_I.

Figure 3.23: Measurement method for EXSY_O 200 $\mu$m slit position. The same method is used for EXSY_I.