Production of the Module Frames

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hier!

Two or three scintillator modules are being assembled to one module frame in building R12 of the Rutherford Appleton Laboratory. The modules are being wrapped in aluminium foil, photomultipliers are glued to them and wrapped with light tight polyethylene foil. Then the frames are being tested and transported to R55, where they are being installed at the walls of the KARMEN blockhouse.

The following pictures document several steps of the production of the module frames:

View into hall R12. Two frames are being produced by two different teams in parallel at two assembling tables. Before the scintillator bars are used, they are measured and the tolerances (in the order of millimetres) are being checked.
A vacuum lifting tool has been used to lift a scintillator bar out of its box and to remove the packing material. The bar will be laid down on a mounting table, covered by a sheet of aluminium foil. The foil will be wrapped around the bar.
The bar lays on the table and the lifting tool has been removed. A 6 cm thick scintillator block is attached to the ends of the bars. It is used as a light guide into the photomultipliers, so that the bars can be positioned without too large gaps between them.
At the light guides of the bar (thicker ends) mirrors are being glued to the scintillator to improve light collection. After being wrapped with aluminium, the bar is lifted again an laid down near to another bar, already on the table. The gaps between the two bars is less than 1 mm.
A steel frame is laid on top of three completely wrapped bars. Boron polyethylen is used to capture thermal neutrons in the vicinity of the scintillator bars. First step is cleaning ...
The lifting of the polyethylene sheets ... and inserting the sheets into the frame.
The polythylene is being fixed to the frame. One very important step: naming each frame after a beautiful woman. The ceremony includes a picture.
After securing the frame with bows, one can rotate the whole table round its axis. The table and the frame are now in glueing position. The scintillator is being abraded where the photomultipliers will be glued to it.
The photomultipliers are being fixed with springs. Optical cement (a glue consisting of two components, looking like glass and having the same index of refraction like the scintillator) is used to optically couple the photomultipliers to the scintillator.
The glue has dried over night and the springs have been removed. You can see the photocathodes of the photomultipliers through the lightguide, reflected at the mirrors. Cabling of the photomultipliers: high voltage (orange) and signal cables (grey) are being attached to the photomultipliers. The signals will be passively summed up in the small unit in the center and fed into the signal cable on the left.
Marilyn and the Dreamteam. The cables of all three bars have been fixed to the polyethylene.
The first black polyethylene foil has been attached, the cables have been fed through and the gaps have been taped to make it light-tight. The complete frame has to be absolutely light-tight. Four PhD students are necessary to wrap the large polyethylene foil, used as a second outer layer around the whole frame.
The large foil lies on top of the frame. To wrap it behind, under and round the frame, the frame has to be lifted with the crane. Wrapping is completed and the frame has been lifted with the crane.
Carefully the frame is being manoeuvered into a carriage, which can carry up to two frames from the assembling hall down to the experiment hall. The foil around the carriage is used as protection against rain. The carriage is being moved with less than walking speed.

Back to the KARMEN Photo Gallery

	View into hall R12. Two frames are being produced by two different teams in parallel at two assembling tables.		Before the scintillator bars are used, they are measured and the tolerances (in the order of millimetres) are being checked.
	A vacuum lifting tool has been used to lift a scintillator bar out of its box and to remove the packing material.		The bar will be laid down on a mounting table, covered by a sheet of aluminium foil. The foil will be wrapped around the bar.
	The bar lays on the table and the lifting tool has been removed.		A 6 cm thick scintillator block is attached to the ends of the bars. It is used as a light guide into the photomultipliers, so that the bars can be positioned without too large gaps between them.
	At the light guides of the bar (thicker ends) mirrors are being glued to the scintillator to improve light collection.		After being wrapped with aluminium, the bar is lifted again an laid down near to another bar, already on the table. The gaps between the two bars is less than 1 mm.
	A steel frame is laid on top of three completely wrapped bars.		Boron polyethylen is used to capture thermal neutrons in the vicinity of the scintillator bars. First step is cleaning ...
	The lifting of the polyethylene sheets ...		and inserting the sheets into the frame.
	The polythylene is being fixed to the frame.		One very important step: naming each frame after a beautiful woman. The ceremony includes a picture.
	After securing the frame with bows, one can rotate the whole table round its axis.		The table and the frame are now in glueing position. The scintillator is being abraded where the photomultipliers will be glued to it.
	The photomultipliers are being fixed with springs.		Optical cement (a glue consisting of two components, looking like glass and having the same index of refraction like the scintillator) is used to optically couple the photomultipliers to the scintillator.
	The glue has dried over night and the springs have been removed. You can see the photocathodes of the photomultipliers through the lightguide, reflected at the mirrors.		Cabling of the photomultipliers: high voltage (orange) and signal cables (grey) are being attached to the photomultipliers. The signals will be passively summed up in the small unit in the center and fed into the signal cable on the left.
	Marilyn and the Dreamteam.		The cables of all three bars have been fixed to the polyethylene.
	The first black polyethylene foil has been attached, the cables have been fed through and the gaps have been taped to make it light-tight. The complete frame has to be absolutely light-tight.		Four PhD students are necessary to wrap the large polyethylene foil, used as a second outer layer around the whole frame.
	The large foil lies on top of the frame. To wrap it behind, under and round the frame, the frame has to be lifted with the crane.		Wrapping is completed and the frame has been lifted with the crane.
	Carefully the frame is being manoeuvered into a carriage, which can carry up to two frames from the assembling hall down to the experiment hall.		The foil around the carriage is used as protection against rain. The carriage is being moved with less than walking speed.