Appendix 1: Assembly

Note: much of this is obsolete, especially that concerning data collection!

In the discussion to follow, SAM may refer to the complete assembly, or simply the press. Which meaning is used should be clear from context. The complete assembly is too large and unstable to be moved into the hutch in one piece, so it must be partially disassembled into four components before moving. These components are the Base, the Pedestal, the Huber 2q circle, and the press itself.

A1.1 Electrical Assembly

Changes since the switch to EPICS are shown in Table I

A1.1 Power

Three 20 ampere 110VAC lines are required. The rack which contains the CAMAC crate has two separate power cords; these must go into two of the lines. The third line is used for everything else (MCA, peripherals, etc.).

A1.2 Controls for Motors

The motors are controlled by custom made drivers which, in turn, are controlled by a series of CAMAC modules: Two E500 8 channel Stepping Motor Controllers (SMC's), an IO 612 Dual I/O Register, a 3388 GPIB interface, a 3290 dataway display, and a 3789 RS232 Crate Controller. In addition, there are two E505 manual controllers on the end of cables which can manually control the motors connected to each of the E500 SMC's. The crate controller is connected to port 3 of the VAXstation.

There are fourteen motors driving the incident x-ray slits (2), the Huber 2q circle , the depressurization valve , the pedestal (4), the base (5), the image plate translator, and the heater. Limit switches are now connected to all of the motors except the depressurization valve, but they haven't been completely tested. Be very careful. The motor numbers, mnemonics, and other information are shown in Table I.

The "old" system had up to 18 motors run off of two E500 stepper motor controllers. Of these, 10 have been rendered obsolete and removed (motors 3, 4, and 9-16; see table below). A third E500 with six new motors have been added (motors 19-24). All additional motors are driven with OMS motor controllers. Motors 25-32 run off of OMS 0. Two additional OMS controllers are to be installed to operate the new monochromatic side station.

Table I Motor Assignments revised 2005

A1.3 Detector Assembly (obsolete)

The detector assembly (Canberra #PSR10010) has 4 cables which connect to two modules in the NIM bin which goes in the hutch. The high voltage cable goes to the Canberra 3105 power supply, and the other three go to the input, power inhibit, and preamplifier power connectors in the Canberra 2020 spectroscopy amplifier. The output cable from the 2020 goes through the hutch wall to the input of the Canberra Series 35+ Multichannel Analyzer. In addition, for multichannel scaling, another short cable goes from the Bipolar output of the 2020 to the input of the 2030 Single Channel Analyzer; the output of which goes to input 3 of the Hex Scaler in the CAMAC Crate. Data from this scaler is recorded by the SAM85 program directly during various step scans.

A cable should be connected between the PUR (Pile Up Rejection) connectors on the 2020 and the MCA. This will improve the performance at high count rates.

A1.4 Multichannel Analyzer (obsolete)

The Canberra Series 35+ Multichannel Analyzer is connected to the VAXstation computer via a serial cable from J101 EIA to port 2 on the VAXstation. As currently set up, the amplifier in the Series 35 MCA is not used; pulses are amplified by the 2020 Spectroscopy Amplifier.

A1.5 Controls for Motors Run by the X17 CAMAC Crate

The upstream apertures (also called BLA or Beam Line Apertures), and the monochromator are both controlled through E500 stepper motor controllers, similarly to those discussed above. As many people use this system, you may have to reconnect the proper controllers, etc. E500s. all have 4 connectors on the front panel; the top one is for the data out; the second one is for a loop-through; the third one is for limit switches, and the bottom one is for an E505 hand-held controller.

A1.5.1 Upstream Apertures

The upstream apertures are permanently connected, so you shouldn't have to make any changes in their wiring. Their control is discussed in section 8.1.

A1.5.3 Monochromator

The monochromator is permanently connected, so you shouldn't have to make any changes in its wiring. Its control is discussed in section 8.2.