25Ω for DLD120 and about 40Ω for the HEX120. These are the values for the standard RoentDek anodes. If you
have ordered and received a special type, the resistance might be different. Note, that even after testing for the absence
of a short between wires, at any time, after assembly, installation, baking or after biasing the detector, a metallic dust
particle from the environment can short signal and reference wires. If such a problem persists contact
RoentDek
for advice.
For DLD120 or HEX120 please continue with (4).
2. Remove the ceramic ring from the assembly (if pre-mounted). Two of the shields can be retracted to liberate the stack
after the M2 screws are loosened. Note, that the shields must not touch any contacts on the ceramic rings and that
the spring clamps that hold the stack together are mounted with about 45° angle with respect to the delay line so that
they are not touching any metal part. This orientation has to be resumed when re-assembling the detector.
3. Optionally: a mesh can be glued, soldered or spot-welded directly onto the front side of the front ceramic ring, such
being at a position of 1.5/2mm in front of the MCP surface. However, we recommend using one of the
RoentDek
detector meshes of type (w)Mesh 40/80/120 which can be mounted to the front ring.
4. Prepare the connection cables for the MCP detector and the delay-line anode. If you have ordered a FT12(16)TP you
should have received these connection cables. For the MCP and holder connection 3 (single) cables are used. For the
anode 4 or 6 (Hex) cable pairs with proper impedance (ideally 100-150Ω) are needed. Unless you have received special
cable pairs or twisted pairs with adequate lengths you must form twisted cable pairs: The two cables of a pair must
have equal lengths within a few mm. The pair must be twisted at least 3 turns per 10cm to form a well-transmitting
twisted pair cable line. For connecting these cables to the delay-line terminals special 2mm connector pins are
provided. The three other single cables are needed for “MCP front”, “MCP back” and “Holder” which is the metal
anode body (see also next section). A fourth single cable can be used for connecting a mesh.
5. For DLD40, DLD80 and HEX80: The cables for the MCP connections can be soldered or spot-welded directly onto
the metallization of the ceramic rings or clamped to the ring with special recessed M2 nuts and screws (obtainable
form
RoentDek). Also special 3mm and/or 2mm lugs for crimping a cable can be supplied. If soldering preferred
use the metallization strips which are not located at a hole of the ceramics. Do that before mounting the MCP.
Alternatively a set of special M2 nuts with short M2 screws can be provided for clamping, or special spring clamps
that can be placed between the rings at the position of a metallization located on a hole. Contact one side of each ring
with a cable to bias “MCP back” and “MCP front” respectively.
For DLD120 and HEX120 or 100: The cable for the “MCP back” connection can be fixed by a M2 screw to the rear
MCP plate. The cable for the “MCP front” connection is either clamped to the front ring with one of the M3 polyimide
screws or for newer systems alternatively via an M2 screw that can be fixed to the front ring (see also Chapter 1.2.4.2).
A cable for the anode “holder” can be connected anywhere on one of the metal M2 rods in the anode, or any part
electrically connected to that, see Error! Reference source not found..
You may clean all parts
in an ultrasonic bath for a few minutes with a mild alcoholic solvent like
isopropanol. MCP should only be exposed to a cleaning procedure if they have some surface contamination that
cannot be removed by spraying with dry air. Please contact
RoentDek for further advice. For MCP general handling
see also instructions on the manufacturer’s web sites or in the
Appendix of this manual. Touch MCPs only with care
along the rim, preferably with gloves. If the MCPs need replacement mount a set with matching electrical resistance
only.
Alternatively
RoentDek can supply an intermediate shim ring with bias contact lug on demand.
Now the detector can be finally assembled, preferably under clean room conditions
Connecting the Wires to the Delay-line Anode
A proper design and use of connection cables is essential for a decent detector performance. Therefore we strongly recommend
using the feedthroughs of type FT12 for the delay-line connections (DLD and HEX). For the DLD the FT12 can also
accommodate the bias for the other detector parts, while for the HEX an additional feedthrough set is required to connect
Holder, MCP front and MCP back (and an optional mesh), for example the FT4
*
. Please refer to Chapter 0 of the manual
*
The FT4 and FT12 are combined to the FT16 feedthrough set for HEX detectors
Page 12 of 83 MCP Delay Line Detector Manual (11.0.1304.1)
To Next Page
Loading...