1. Turn off power supplies SM0X, SM0Y if not already off.

2. Lock out power supplies SM0X, SM0Y.

3. Remove the rubber insulating sheets covering the DC power cables where they connect to the Wobbler magnet.

4. Confirm that the DC cable <--> coil terminal connections are clearly labelled so that the correct hook-up can be made when the Wobbler is re-installed.

5. Disconnect the DC cables at the magnet, pull them back out of the way, so the ends hang down the downstream side of the gas target support frame. Cover the exposed ends with the rubber sheets.

6. Disconnect the ground wire from the magnet, roll it back out of the way.

7. Turn off the cooling water. Disconnect the water supply and return lines at the magnet. Block or connect together the two ends of the water lines, to avoid flooding if/when that cooling circuit is turned on again.

8. Having ensured the beampipe through the Wobbler has been vented to air, slide the sleeves connecting this beampipe to the upstream and downstream pumping system, so as to free the Wobbler pipe.

9. Loosen the set screws which attach the magnet mount to the gas target frame, lift away the Wobbler magnet complete with its beampipe and collimator drive mechanisms. Put it in the box marked 'DRAGON Wobbler' upstream of the gas target on the N.E. side of the HEBT line, being careful not to bump the collimator drive rods.

10. Remove the blankoff flange and adapter ring from the pumping manifold, protect exposed sealing surfaces, and put them in the Wobbler box. Save the clamps for use in step 16, below.

11. Remove the alpha source holder from the underside of the middle upstream pumping stage. Detach the alpha source (if still present) and store it in the radioactive source storage box. Put the source/ degrader holder (upside down) in the Wobbler box.

12. Remove the pieces which adapted from pumping stage boxes to Wobbler beampipe and re-attach them to the Wobbler using the sleeves.

13. Store any other small items (e.g. alternate size of collimator) in a small closed box and put them in the Wobbler box. Screw down the lid of the Wobbler box. [Question: are any of the o-rings special?]

14. From the cardboard box marked 'Gas target box' in DRAGON storage cabinet #2, remove the pieces which adapt the pumping-stage boxes to the gas target box and install them on the pumping boxes.

15. Remove the assembly of gas target outer box and adapter to 6" manifold and ensure that coupling sleeves are in place on the gas-box pipes.

16. Mount the gas target box with the removable side plate on the S.W. side, connecting to the upstream and downstream stages by the coupling sleeves and to the 6" pipe below.

17. Check that gas cell entrance and exit apertures are the desired sizes. If necessary, replace them with correct apertures (stored in 'small parts' box in the gas target storage box). Check the elastic monitor collimator size and replace if necessary. Check that the Si monitor detectors are in place and connected to the signal/bias feedthroughs. Connect any auxilliary devices to 'spare' feedthroughs.

18. Mount the cell-supporting side plate on the target box. Connect the flexible bellows from the recirculation system. Connect the capacitive manometer tube.

19. Pump down the target box. Cell pressure should read a small fraction of a Torr on the capacitive manometer. When pumping is turned off and the system isolated, pressure rise should remain below 0.5 Torr per 24 hours. Otherwise, find the leak(s) before attempting any loading of the cell with hydrogen.

20. Connect the coax cables from Si detector pre-amps, the cell temperature thermocouple lead, and signal cables for any other auxilliary devices.

How to replace the gas target box with the Wobbler magnet

1. Reverse the above sequence.

dah
24/4/2001