E-Detector Motion System

Motion Mechanism GUI

• login to cdaql* as cvxwrks
• cd MEDM/compton
• edm -x HLC_E_CompED.edl

Parking the detector

During standard running conditions, the above GUI at top left shows X = -8.6890. We park it to Garage whenever

1. when we expect beam to be re-tuned through the chicane after a beam studies or a long down
2. we are sure of not running for a couple of days at a stretch
3. when the beam is intended to be taken straight through (instead of the chicane)

The procedure for parking is:

1. The detector can be moved only when the beam is off.
2. Call MCC and request to mask Compton electron detector motion FSD. Make sure that they have masked before starting to move.
3. In the drop-down box on the left-middle of the e-detector motion GUI, choose 'GO HOME' You should start seeing the box indicating that the detector is moving gets highlighted by yellow.
4. Check to see that the motion is complete. You see the position readback to be X=0.0000 and the yellow highlighting is off.
5. From the same drop-down menu, now select the 'Garage' and the detector start going to Garage.
6. On completion of this motion again, the yellow highlighting goes away and the detector is well parked now.

General Description

• The electron detector is connected to the QWAD using the custom made [Flex-cable]. The detector is placed inside the vacuum-can whereas the QWAD boards are connected from outside the vacuum-can using appropriate flanges used between the Flex-cable and the QWAD. The connection between e-detector and the QWAD (if the vacuum - can was transparent) can be depicted as in the attached picture.

• The electron detector vacuum - can has a motion mechanism to allow us to move the detector vertically in and out of the beam along with the ability to rotate the detector facing the beam. A schematic view of the assembly can be seen here.

• We are using a stepping motor identified as KML062S04 for vertical motion ( data sheet ) of detector using a MDC accuator ( specifications ). This motor is being controlled by a single axis IDC Controller (User Manual). The Motion Controller can be controlled through its keypad or via computer terminal after installing its software provided on their website

• Motion Controller:
  • Vertically downward motion of the actuator is referred to as 'positive' direction based on the current settings of the controller.
  • All numbers displayed on the controller uses appropriate units of inch and second
  • The Actuator has 3 physically verifiable positions which correspond to a switch on the actuator.
    • EOT+ (end of travel switch in positive direction) will not be used
    • EOT- (end of travel switch in negative direction) used as Garage
    • Home
  • Current Controller Settings:

1. Current: 1.5A
2. Resolution: 18000
3. Inductance: 16 mH
4. Direction: positive
5. Distance Unit: cm
6. Velocity: cm/s
7. Acceleration Unit: cm/s^2
8. Gear Ratio: (GR) = 10:1

Operation

At EOT- (physically top most) the actuator position read back (as seen on the controller display) is

 -3.7833
 00000000      00000000

AC.02 VE.1 DA2 GO

 +2.0000
 00000000      00000000

AC.02 VE.1 DA1 GO

 +1.0000
 00000000      00000000

AC.02 VE.1 DA-2 GO

 -2.0000
 00000000      00000000

AC.02 VE.1 DI1 GO

 -1.0000
 00000000      00000000

Controller Settings

We shall maintain two files for the controller settings

• The most recent settings updated on Nov 29, 2010
• The last working settings updated on Oct 14, 2010

The list of programs loaded in the current configuration are

1. Prog 1: Go Home;
2. Prog 2: 2 cm above chicane beam;
3. Prog 3: Garage, EOT-;
4. Prog 4: 5 mm above chicane beam
5. Prog 10: Incremental motion : -2 mm
6. Prog 11: Incremental motion : -1 mm
7. Prog 12: Incremental motion : +1 mm
8. Prog 13: Incremental motion : +2 mm
9. Prog 14: Incremental motion : -0.5 mm
10. Prog 15: Incremental motion : +0.5 mm
11. Prog 16: Incremental motion : -0.2 mm
12. Prog 17: Incremental motion : +0.2 mm
13. Prog 98: Motor Stopper