H7844 Datasheet, PDF (1/4 Pages) Hamamatsu Corporation – PHOTOSENSOR MODULE WITH THERMOELECTRIC COOLER

PHOTOSENSOR MODULE
WITH THERMOELECTRIC COOLER
H7844
Reduces dark current to 1/50 that at room temperature
after only 3 minutes of cooling
The H7844 is a photosensor module consisting of a newly developed high
sensitivity side-on photomultiplier tube, a high-voltage power supply cir-
cuit and a thermoelectric cooler. Cooling is super-efficient in the H7844
because the thermoelectric cooler is directly coupled to the photocathode
of the photomultiplier tube. This also drastically reduces thermal noise
(thermal electrons) emitted from the photocathode to allow making accu-
rate measurements with a high signal to noise ratio even at very low light
levels. As a result of cooling, dark current reduces down to 1/50 at room
temperature after only 3 minutes of cooling.
Besides shorter cooling time and lower power consumption compared to
conventional methods that cool the entire photomultiplier tube, the H7844
completely eliminates the problem of condensation during cooling.
SPECIFICATIONS
(at 25 °C)
Parameter
Input Voltage
Max. Input Voltage for Main Unit
Max. Input Current for Main Unit
Max. Input Voltage for Thermoelectric Cooler
Max. Input Current for Thermoelectric Cooler
Max. Output Signal Current *¹
Max. Control Voltage
Recommended Control Voltage Adjustment Range
Effective Area
Spectral Response Range
Peak Sensitivity Wavelength
Luminous Sensitivity
Min.
Typ.
Blue Sensitivity Index (CS 5-58) Typ.
Radiant Sensitivity *²
Typ.
Luminous Sensitivity *¹
Min.
Typ.
Radiant Sensitivity *¹ *²
Typ.
Gain *¹
Typ.
Dark Current *¹ *³
Typ.
Max.
Equivalent Noise Input (ENI) *¹ *² *³
Rise Time *¹
Ripple Noise *¹ *⁴ (peak to peak)
Max.
Settling Time *⁵
Operating Ambient Temperature *⁶
Storage Temperature *⁶
Weight
Value
+11.5 to +15.5
+18
40
3.75
3.9
58
+1.2 (Input impedance: 100 kΩ)
+0.3 to +1.1
9 × 14
185 to 900
400
140
300
9.0
76
400
3000
7.6 × 10⁵
1.0 × 10⁷
0.1
0.5
2.4 × 10^-17
2.2
0.5
0.2
+5 to +40
-20 to +50
290
Unit
V
V
mA
V
A
µA
V
V
mm
nm
nm
µA/lm
—
mA/W
A/lm
A/W
—
nA
W
ns
mV
s
°C
°C
g
*1: Control voltage +1.0 V (PMT supply voltage -1000 V), with cooler operated
*2: At peak sensitivity wavelength
*3: After 30 minutes storage in darkness
*4: Signal cable RG-174/U, Cable length 450 mm, Load resistance 1 MΩ, Load capacitance 22 pF
*5: The time required for the output to reach a stable level following a change in the control voltage from +1.0 V to +0.5 V. *6: No condensation
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Information furnished by HAMAMATSU is believed to be reliable. However, no responsibility is assumed for possible inaccuracies or omissions. Specifications are
subject to change without notice. No patent rights are granted to any of the circuits described herein. ©2005 Hamamatsu Photonics K.K.