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MCP Delay Line (Version 6.2.90.5)
1.
Remove the power cable of the
DLATR6(8)
or retract it from the NIM crate so that the power is not engaged.
2.
Set the switches for “MCP front” and “MCP back” signal to “poti”.
3.
Open the side panel of the
DLATR6
(the one with only 6 fixing screws) or the lid of the
DLATR8
respectively and remove the input cables of the amplifiers 3-6(8). The cables are labeled accordingly.
Remember where to place them again later. Notice: Some
DLATR6(8)
models have extra protection circuits
(“fuses”) between the amplifier input and the connection cable. Leave them connected to the cable board.
4.
Close the side panel (lid) again.
Warning: If you leave the side-panel (lid) open and increase the voltage for any detector part, this
voltage is exposed on various contacts inside the module and you risk a potentially fatal electro-shock
when touching these contacts
!
5.
Remove “MCP back” and “Holder” input cable (SHV inputs) on the front side panel of the
DLATR6(8)
module. Now the “Holder” and “MCP back” potentials are floating. If you now apply voltage to the “MCP
front”, the whole MCP stack will follow this voltage (for that reason the holder potential must also be floating).
There is no voltage across the MCP stack now.
6.
Raise the potential of “MCP front” to whatever voltage you want to apply in later operation. While you increase
the potential you should verify that no current is flowing through the MCP stack (MCP back is floating). If no
discharge occurs after a few minutes reduce the voltage again, turn off the power supply and reconnect the
“MCP back” and “Holder” SHV inputs on the rear panel.
The detector can already be considered rather safe now for
ion detection mode
(high negative potential on “MCP
front”, low potential to ground on “MCP back” and the anode). If you want to operate in this mode you may
open the side panel again, re-connect the amplifier inputs inside the
DLATR6(8)
module and close the side
panel. Resume power to the
DLATR6(8)
module and set the switches for channels 1 and 2 to the “on”
position. If you use the
FT12/16-TP
connect the outputs to the
ATR19/NDLATR6(8)
again. Connect all
high voltage cables. Verify the noise levels again. You may continue with section 5.3
.
For
electron detection mode
continue with step 7.
If a discharge occurs you must verify all your connections inside the chamber again. Verify that there is sufficient distance to
any part close to the detector which carries different potentials than the detector parts. After sufficient pumping time resume
the test procedure from the beginning. If the problem persists, contact
RoentDek
for some advice.
If you plan to operate the detector in
electron detection mode
(high potentials on “MCP back” and the anode) you need to verify
the high voltage safety of the rear detector parts.
7.
For
electron detection mode
you must verify the high voltage safety of the anode and the “MCP back” contact.
Connect all high voltage cables except the “MCP front” (SHV) input on the
DLATR6(8)
front panel or the
FT12(16)-TP
. The front side of the MCP stack is now floating. If “MCP front” is close (< 5mm) to another
biased part of your setup (mesh on contact “X”? Spectrometer exit?), set this part on floating potential, too.
8.
Raise the potentials on “MCP back” and the anode to the expected operation potentials. Note again that there
is no current due to the floating “MCP front”. If no discharge occurs after a few minutes reduce the voltage
again, turn off the power supply and re-connect the “MCP front” SHV input, and all other previously removed
connection. The detector can be considered rather safe now also for
electron detection mode
. Set the switches for
channels 1 and 2 to the “on” position again.
9.
Open the side panel (lid) of the
DLATR6(8)
. As you have applied potential to the anode wires, the cables that
connect with the amplifier inputs can carry an electric charge. Avoid touching the metal cable contacts and
discharge each one (pair) of the cable contacts with a grounded wire before reconnecting them to the amplifier
inputs. Close the side panel and resume power to the
DLATR6(8)
module. If you use the
FT12(16)-TP
connect the outputs to the
ATR19/NDLATR6(8)
again.
If a discharge occurs you must verify all your connections inside the chamber again. Verify that there is sufficient distance to
any part close to the detector which carries different potentials than the detector parts. After sufficient pumping time resume
the test procedure from the beginning. If the problem persists, contact
RoentDek
for some advice.
Summary of Contents for DLD120
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