E-Detector Motion System

Introduction

• 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 is placed outside 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)

• 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)
    • EOT- (end of travel switch in negative direction)
    • Home
  • Current Controller Settings:

1. Current: 1.5A
2. Resolution: 18000
3. Inductance: 16 mH
4. Direction: positive
5. Distance Unit: inch
6. Velocity: inch/s
7. Acceleration Unit: in/s^2
8. Gear Ratio: (GR) = 25:1

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

• one, having the most recent settings
• second, having the last working settings