************************************* *SPARES FOR THE MEGHA MODULES AT ANU* ************************************* Status as of 13 October 1997 DLW GENERAL ******* 1) Each module is numbered. 1 to 5 are in ANU at present. The major parts of each module should not interchanged so ensure you have the correct backplate on the correct body etc. 2) There is a plastic box for each module that should contain the smaller parts for that module. If you dismantle a module for any reason please ensure that ALL the bits are placed in the appropriate box. REMEMBER you might not be the person to reasemble the module and a LOT of time can be wasted looking for bits that have just been left lying around on the bench and if some vital parts are lost then it may not be possible to complete the reassembly until a new part is made and that could compromise the experiment. 3) There is a larger plastic box that contains the general spares for the modules and vacuum chamber. 4) The spare parts for the strip detector array are kept in a second large plastic box. This box also contains the target ladders and accessories and the alignment apertures. 5) The large items such as grids, windows, detector PCBs,O-rings etc. are stored in larger labels boxes sored in the cupboard in the experimental area. Major MEGHA Spares. ******************* Cathode (Shield) grids 3 centre module 3 others Anode grids 3 centre module 3 others(one with pins on resistor side instead of wire side. Use this one only in an emergency) Detector PCBs 2 Unused Windows (3.5 microns) 3 centre module 6 others Pre amp boards (unmounted) 20 Hi gain 10 low gain CsI preamp boards 8 high gain Base plate PCBs 1 set 16 way Feedthroughs 5 Spare CsI ribbon cables 2 CsI Feedthrough covers 1 Status of the Modules ********************* Module 5 ( for position D) -------------------------- The base plate feedthroughs have been replaced by ones sealed with Araldite 2019. The base plate PCBs are in place. These will only need checking for continuity. The major parts for this module are inside the module and the rest are in the Plastic Box # 5. The internal parts other than the baseplate PCBs will need cleaning. The module is stored in the centre cupboard in the LINAC room. Handle it with care if you need to move it so as not to damage the feedthroughs. There are some parts missing from Box 5 a) 4 off 2.5mm x 47.0mm b) one set of grid leads with 3 wires ( there is only a centre module set available). Module 4 ( position R) ----------------------- This module is internally as it was left at the end of the Dec 1996. This module has preamps with the new design of PCB, they have been tested with the pulser and seem OK Module 3 (position C) ----------------------- This module is internally as it was left at the end of the Dec 1996. This module has preamps with the new design of PCB, they have been tested with the pulser and seem OK Module 2 (position L) ----------------------- This module is internally as it was left at the end of the Dec 1996. This module has preamps with the new design of PCB, they have been tested with the pulser and seem OK Module 1 (position U) ----------------------- This module is internally as it was left at the end of the Dec 1996. It does not have scintillators in place. The necessary parts are in Plastic Box # 1. Note that some of the scintillator in the control room have there teflon collars and springs in place they should be used for this module. This module has preamps with the new design of PCB, they have been tested with the pulser and seem OK Pre amp modules ---------------- There are no spare preamp modules (18 preamp sets) in ANU. Need three for the down module and three spares plus one centre module spare at least. The cans and connection boards are available in ANU plus two spares and a spare centre one for the centre module. All have 100K Ohm drop down resistors Tests on Detectors with new preamps ----------------------------------- The diagram is drawn looking at the upstream side of the patch panel with beam going into the page. Blank Spaces do not have detectors in place. OK ? indicates that the effect of the high voltage on the noise was too small to see or that no current was drawn (i.e. <0.1 micro amps) U |------------------| | OK | OK |Short | |------------------| | OK | OK | OK | L |------------------| R | OK | OK | OK | |----------------------------------------------------| | OK | OK | OK | OK | OK | OK | OK | Short| OK | |----------------------------------------------------| | OK | OK | OK | OK | | OK | OK? | OK? | OK?| |----------------------------------------------------| | OK | OK | OK | OK | OK | OK | OK? | OK? | OK?| |----------------------------------------------------| | | | | |------------------| | | | | |------------------| | | | | |------------------| R No 75MHz oscillations appear on any of these. Cabling from all modules to the overhead patch panel connects the row and column on the module to the same row,column on the patch panel. PLEASE KEEP TO THIS CONVENTION! NOTE that the sections A,B,C in the preamp cans do NOT run in the same order for all cans because the top can in each module is reversed wrt the others! To ease re-wiring, the cabling bundle to the patch panel is done so that the number of each cable rises ( not always by 1!) with the signal order Positions(a,b,c,d) Energy E. Gas signals are in a separate bundle. General spares required *********************** More springs for mounting the scintillators More O-rings suitable for the back plate of the module and sealing it to the chamber. 2.4mm diameter cord 207mm square for the module and 211-212 mm square to seaL to the chamber. More large 0-rings for the break point of the chamber 7mm diameter cord and 710 mm internal diameter More resealed multiway feed throughs