P61 STEERING TO T8   Lau Gatignon / SL_EA

The optics is the same for proton and ion operation.

HORIZONTAL PLANE

1. Steering through TAX(12) and TAX(13)

Select a small hole in TAX(8), e.g. by SET TAXMOT(8)=100
Scan Bend-1 onto TRIG1 with steps of 3.8 Amps/mm

2. Correct for horizontal angle in TAXMOT(12) and TAXMOT(13)

From optics in backward direction one obtains:

                             R12 at TAX                 R22 at TAX         
       BEND-6               49.832mm/mrad            0.189 mrad/mrad       
       TRIM-2              28.261 mm/mrad            2.094 mrad/mrad       
       BEND-5              21.201 mm/mrad            1.783 mrad/mrad       

Use a linear combinatioon of BEND-6 and TRIM-2, according to

xTAX = 49.832 B6 + 28.261 TR2
x'TAX = 0.189 B6 + 2.094 TR2

To keep xTAX = 0, steer with B6 - 1.763 TR2. 1 mrad for B6 gives -3.5 mrad at the TAX

3. Steering through COLLS 1 and 3

Before starting this tuning, make sure that the transmission through B5T is good.
Use a linear combination of TRIM2 and TRIM3 according to

                               COLL 1                     COLL 3           
       TRIM-2                540 mm/mrad               -570 mm/mrad        
       TRIM-3                170 mm/mrad               -115 mm/mrad        

hence

       Bends                   COLL 1                     COLL 3           
       TRIM-2                540 mm/mrad                don't care         
   TR2 - 4.96 TR3           -300 mm/mrad                    0              
   TR2 - 3.18 TR3                 0                    -200 mm/mrad        

4. Steering through COLL-5

Scan BEND-7 through a small slit in COLL-5 onto TRIG-1. Sensitivity 0.28 Amps/mm

5. Steering towards Fiscs at T8

Scan through Q20 aperture with BEND-8, sensitivity 1.0 Amps/mm.
Center at T8-Fiscs with TRIM-10, sensitivity 6.3 Amps/mm

VERTICAL PLANE

6. Position of TAX(12) and TAX(13)

Study transmission as a function of TAXMOT(13) position. Choose position with optimal transmission. TAXMOT(12) and TAXMOT(13) have shown good relative alignment.

7. Steering through COLLs 2 and 4

Use a linear combination of TRIM1 and TRIM4

                               COLL 2                     COLL 4           
       TRIM-1               -300 mm/mrad               -30 mm/mrad         
       TRIM-4                  60 mm/mrad                41 mm/mrad        

hence

       Trims                   COLL 2                     COLL 4           
       TRIM-1               -300 mm/mrad                don't care         
   TR1 + 0.73 TR4           -345 mm/mrad                    0              
   TR1 + 5.0 TR4                  0                    175 mm/mrad         

8. Steering through COLL-6

Scan TRIM-6 through a small slit in COLL-6 onto TRIG-1. Sensitivity 4.5 Amps/mm

9. Steering towards Fiscs at T8

Scan through Q19 aperture (-> angle at T8) with TRIM-9 and TRIM-7.

                       T8-FISC                Q19          
    BEND-10         26.5 mm/mrad          don't care       
    TRIM-9          -21.5 mm/mrad        61.5 mm/mrad      
    TRIM-7          -10.2 mm/mrad         -375 mm/mrad     

TR7 - 0.474 TR9 gives 1mm at Q19 for 1.6 Amps in TR7 without changing the position at the Fisc at T8.

Then steer to T8 Fisc with BEND-10, sensitivity 4.5 Amps/mm

Last updated : 26 July 1996 by Lau Gatignon