DSG HPGe User manual

Maintenance check / pretest
Ge detectors may operate at bias voltages of 5000 V DC or more.
Always be sure that detectors are properly grounded (through the HV
coaxial cable ground to a properly grounded Power upply/NIM Bin).
Also use extreme caution when adjusting internal preamplifier controls to
avoid contact with the high voltage circuit.
Connect the Oscilloscope with a BNC cable or BNC T-fitting (picture 1)
on the main amplifier OUT (picture 2 - picture 4).
Picture 1 Picture 2 Picture 3 Picture 4
D G Detector ystems GmbH * Robert-Bosch- tr. 38 * 55129 Mainz* GERMANY
phone: [phone] * fax: [phone] * email: [e-mail]
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Block diagramm
D G Detector ystems GmbH * Robert-Bosch- tr. 38 * 55129 Mainz* GERMANY
phone: [phone] * fax: [phone] * email: [e-mail]
- 2 -
PC
ignal Output
Input
Power
plug
HV Out
TTL
Detector
BNC cable
B
N
C
c
a
b
l
e
OUT
BNC
Power cable
H
V
c
a
b
l
e
Test BNC N/C
TTL
BNC
HV
HV
r
i
b
b
o
n
c
a
b
L
e
ADC
DSG 3
Main amplifier
DSG 1 3 A
HV modul
Front panel Front panel
Rear panel Rear panel Rear panel
Ribbon cable
BNC/ HV cable
Detector cable
Oscilloscope
B
N
C
c
a
b
l
e
Unipolar

Be sure the settings for coarse gain is 100 and
fine gain is 10 on your main amplifier
The multimeter at ground (with the black cable(COM)) and to the test
point (with the red cable), Teflon socket at the Detector beside the BNC
cable.
Rise High Voltage in 100 V teps and measure the test point.
Wait a little and write down the voltage you measure in a table like shown
below. Also you should have a look at the noise you see on the scope.
Write down the noise
Bias(V) 100 200 300 600 1000 1500 2000 2500 3000 3500 4000 4500 5000
TP (V)
Noise
(mV)
D G Detector ystems GmbH * Robert-Bosch- tr. 38 * 55129 Mainz* GERMANY
phone: [phone] * fax: [phone] * email: [e-mail]
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If you use a non-D G Mainamplifier, please use following settings:
−Fine gain 10
−coarse gain 100,
−Pileup off
−P/Z manual
−BLR Off/Auto
−Peaking time 4/6 µsec
−Output Unipolar
D G Detector ystems GmbH * Robert-Bosch- tr. 38 * 55129 Mainz* GERMANY
phone: [phone] * fax: [phone] * email: [e-mail]
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