C H A N N E L
P H O T O M U L T I P L I E R
C P M
Description
PerkinElmer
Optoelectronics, for-
merly EG&G Optoelectronics, is
pleased to introduce the Channel
Photomultiplier (CPM), a new ultra
high sensitivity optical detector
which replaces conventional photo-
multipliers (PMTs) and avalanche
photo diodes (APDs). This device
uses a unique detector principle, re-
sulting in a compact design with ul-
tra high gain, high dynamic range,
extremely low dark current, and fast
response.
This
high-performance detector offers
fundamental advantages for analytical
instrumentation applications such as
emission spectroscopy, flourescence,
atomic absorption spectroscopy, and
bio and chemo luminescence. The
CPM also delivers important advan-
tages in life science products, indus-
trial and medical equipment, and high-
energy physics.
Features
• Ultra high anode sensitivity
up to 10
7
A/W
• Extremely low dark current,
typically 3pA @ 10
6
gain
• Very low equivalent
noise input (down to 10
-17
W)
• Very high stability in dark current
(no ”bursts”)
• High gain exceeding 10
8
• Very high dynamic range
• Compact dimensions
• Wide spectral response through
multiple window materials
• High resolution
• Fast response time
• High immunity to magnetic fields
• Rugged design
When
compared to conventional
PMTs, the CPM improves anode
sensitivity by one order of magni-
tude, while lowering dark current by
one to two orders of magnitude. The
noise level shows extreme stability
over time, with no ”bursts.” The
extremely low dark current results in
a higher dynamic range than con-
ventional PMTs and extends detec-
table limits for many applications.
The
CPM can be used in analog-DC
mode, single photon counting mode,
and in nuclear spectroscopy (when
coupled to scintillation materials like
BGO, LSO, Nal, etc.). PerkinElmer
Optoelectronics offers a choice of
window materials and photocatho-
des to cover the spectrum from
115 nm (UV range) to 900 nm (NIR).
The
new detector is a small, head-on
type with a total diameter of 10.5 mm
including encapsulation. PerkinElmer
Optoelectronics also offers custom
configurations for specific applica-
tions.
P R I N C I P L E
Principle of Operation
O F
O P E R A T I O N
Physical Specification
Cathode Channel-Entrance
Channel-End Anode
The
CPM, like conventional photo-
multiplier tubes, converts a very low
light level into photoelectrons by a
semitransparent photocathode de-
posited on the inner surface of the
entrance window. On their way from
the cathode to the anode the photo-
electrons pass through a narrow, se-
miconductive channel. Each time the
electrons hit the inner wall of the
curved channel, multiple secondary
electrons are emitted. This effect oc-
curs multiple times along the path,
leading to an avalanche effect with a
gain exceeding 10
8
. The curved sha-
pe of the glass tube improves the
multiplication effect.
-HV
red
-HV +50…+300 V
blue
-20…-50 V
black
Coax
100 V
1 Mohm
-HV
Proposal for Power Supply
PERKINELMER [ PERKINELMER OPTOELECTRONICS ]
