# Design, construction, characterization, and testing of one-channel
electronic module for the Hamamatsu Multi-Pixel Photon Counter S12572-100P

L. Arceo  J. Félix

###### Abstract

The Multi-Pixel Photon Counter (MPPC) or Silicon Photomultiplier (SiPM) can
detect from a single photon to several thousand ones; it has high gain
—$10^{5}$ to $10^{6}$—, low operation voltage —65 to 75 Vdc—, and small size
—typically 3.85 mm $\times$ 4.35 mm $\times$ 1.45 mm—; it is suitable for very
low light level detection applications, like in cosmic ray detectors, in high-
energy particle detectors, and in ionizing radiation detection in general. To
study, test, and apply the Hamamatsu Multi-Pixel Photon Counter S12572-100P,
we proposed a three-electronic-board MPPC module to connect, to feed and read-
out, and to digitize its signal. The MPPC module waveband operation is from
100 Hz to 1 MHz; the ratio of outgoing signal to incoming signal (transmission
coefficient) is about 82 % between 100 Hz–10 kHz and 72 % between 10 kHz–1
MHz; the phase shifts between the incoming and outgoing signals were close to
zero degrees for all frequencies and occasionally, different from zero
degrees; signal transit time is about (741.72$\pm$82.80) ps; the digitizing
efficiency error is 0.88$\times 10^{-3}$ %; the digitizing efficiency is 99.99
%; digitizing time is about (2.96$\pm$0.13) ns. We report on technical details
and physical characteristics of this electronic module to drive the Hamamatsu
Multi-Pixel Photon Counter S12572-100P, and on preliminary physical results
obtained applying this electronic module.

##  1 Introduction

MPPCs offer advantages over traditional Photomultiplier Tubes (PMTs). In many
fields of physics, the applications are many, like data communications,
aerospace, laser range finders, radiation detection in high energy physics and
cosmic ray physics, medicine, and other areas of science, due to their
physical qualities like high speed, high sensitivity, high quantum efficiency,
short rising time, broad wavelength range of detection, unaffected by external
magnetic fields, good operation at moderate room temperature, small volume
—typically 3.85 mm $\times$ 4.35 mm $\times$ 1.45 mm—, small operation
voltage, significant amplification factor, and low-cost.

The MPPC made a high-density matrix of Single-Photon Avalanche Photodiode
(SPAD) pixels operating in Geiger mode; these pixels are arranged in two
dimensions and have high internal gain, which enables single-photon detection
to a lot of photon detection. Its advantages, such as high internal gain and
low operation voltage, make the MPPC a good option for light detection from a
single photon to thousand photons [1, 2] in particular in applications with
very low light levels; this last feature is perfect for developing cosmic ray
detectors, where radiation level is very low [3, 4, 5].

Between all MPPCs, the Hamamatsu Multi-Pixel Photon Counter S12572-100P is an
excellent option, due to its good physical properties and low-cost, on many
applications previously explained.

Normally, the Hamamatsu company only supplies a circuit hint on how to connect
and feed this device, leaving the user with many open possibilities on how to
use it.

To use the Hamamatsu Multi-Pixel Photon Counter S12572-100P, we designed,
constructed, characterized, and tested a three-electronic-board MPPC module,
to connect, to feed and read out, and digitize its signal, with the following
characteristics: 1) it is designed for the Hamamatsu Multi-Pixel Photon
Counter S12572-100P to be attached to the detection material and connected to
this module; 2) it has response time in the order of nanoseconds; 3) it is
adaptable to another Hamamatsu MPPC series. For example, the Hamamatsu optical
measurement module C15524-1310SA, that has a MPPC with similar
characteristics, but does not digitize; for this reason, we developed our own
MPPC module. The MPPC module was tested with a CompactRIO (cRIO) Data
Acquisition System (DAQ) [6, 7, 8] from National Instruments.

In the following sections we present technical details of the MPPC module:
design; construction; characterization and operations; we explain the
experimental setup; describe and discuss results, and give conclusions.

##  2 Description of the MPPC module

In this section, we provide technical description of the design, construction,
operation and characterization of three-electronic-board MPPC module.

The MPPC module has three electronic boards:

  1. 1.

Connection electronic board, where this Hamamatsu Multi-Pixel Photon Counter
S12572-100P is placed to attach it mechanically to the detector material.

  2. 2.

Feeding and reading-out electronic board, to apply the feeding voltage, create
the analogical signal, and read it out.

  3. 3.

Digitizing-electronic board, where the analogical signal is digitized and sent
out to the oscilloscope or DAQ system.

All of them were separately planned, designed, manufactured and tested. We
report on the transmission coefficient of the analogical signal as function of
frequency, the phase shift outgoing signal with respect to ingoing signal,
transit time, digitizing efficiency error, digitizing efficiency, and
digitizing time.

###  2.1 Connection electronic board

The electronic board physically separates the Hamamatsu Multi-Pixel Photon
Counter S12572-100P from its electronics and attaches it mechanically to the
detection material (an 1-in $\times$ 2-in $\times$ 8-in solid aluminum bar,
with one 1-in $\times$ 2-in end polished to mirror-like finishing). In figure
1 (left) we show the manufactured connection electronic board. It is where the
Hamamatsu Multi-Pixel Photon Counter S12572-100P surface mount type is
soldered on the top layer. In figure 1 (middle) we show the connection
electronic board connected to the feeding and reading-out electronic board
without detection material. In figure 1 (right) we show the connection
electronic board attached and assembled to the detection material and
connected to the feeding and reading-out electronic board.

Figure 1:  Left: Connection electronic board, top layer side. Middle:
Connection electronic board connected to the feeding and reading-out
electronic board. Right: Connection electronic board attached and assembled to
the detection material and connected to the feeding and reading-out electronic
board.

###  2.2 Feeding and reading-out electronic board

The electronic board was designed, constructed, and operated to feed the
Hamamatsu Multi-Pixel Photon Counter S12572-100P, and to read-out its analog
signal. In figure 2 and figure 1 (middle), we show the schematic diagram
design and manufactured electronic board of the feeding and reading-out
electronic board, respectively.

Figure 2:  Schematic diagram design of the feeding and reading-out electronic
board for the Hamamatsu Multi-Pixel Photon Counter S12572-100P.

In this electronic board, we measured three parameters:

  1. 1.

The transmission coefficient —outgoing signal amplitude divided by ingoing
signal amplitude — as function of frequency.

  2. 2.

The phase shift, which is the phase displacement of the output signal waveform
with respect to the input signal.

To measure these parameters, we replaced the Hamamatsu Multi-Pixel Photon
Counter S12572-100P analog signal by a Tektronix function generator AFG3101
ranging from 100 Hz to 1 MHz. To measure the input amplitude, the output
amplitude, and the phase shift between signals, the Tektronix oscilloscope
TDS2022C-EDU was employed; from the oscilloscope, we consider a systematic
error of 10 % [9, 10]; it was included in the least square technique to
measure the transmission coefficient as a function of the frequency. To record
the amplitudes and phase shift of the signals, a PC-host with LabVIEWTM was
used.

  3. 3.

The transit time, or propagation delay, or response time [11], —the time an
electrical signal takes to travel through the MPPC module—.

To measure this parameter, we used a Tektronix function generator AFG3101 at 1
MHz, and a Tektronix oscilloscope TDS5104B, to measure the delay between input
and output signals.

###  2.3 Digitizing-electronic board

This electronic board was designed to compare, against the user choice
threshold voltage (three times above the noise signal), and 1-bit digitize the
feeding and reading-out electronic board analog signal. Figure 3 (left) and
(right) show the schematic diagram design and manufacture of the digitizing-
electronic board, respectively.

Figure 3:  Left: Schematic diagram of the digitizing-electronic board; right:
Manufactured digitizing-electronic board.

The ADCMP582 chip (U1), a PECL (positive emitter-coupled logic) output driver,
has a typical one-channel propagation delay of 180 ps [12]; and MC10ELT21DG
chip (U2), PECL to LVTTL family conversion (for achieving cRIO compatibility),
has a typical propagation delay of 3.5 ns [13].

In this electronic board, we measured these three parameters:

  1. 1.

The digitizing efficiency error $eff$ (%), which is defined by the following
equation,

$eff=\frac{1}{n}\sum_{j=1}^{n}\frac{\omega_{j}-\omega}{\omega}\times 100,$
(2.1)

Here $\omega$ is the frequency of the incoming generated function, with
frequency between 1 Hz to 1 MHz with base-10 logarithmic increments.
$\omega_{j}$ is the measured frequency of the outgoing measured function, j is
an iteration number, n is the total number of measurements —1800, one
measurement per second—.

  2. 2.

The digitizing efficiency (%) is obtained by subtracting the digitizing
efficiency error (%) from 100 percent; it depends on the frequency.

  3. 3.

The digitizing time, or conversion time, —the time taken by the electronic
board to discriminate and convert the analog signal into a digital one—; it is
measured using a Tektronix function generator AFG3101 at 1 MHz and a Tektronix
oscilloscope TDS5104B.

##  3 Experimental setup

In figure 4, we show a block diagram of the experimental setup; we run two
tests:

Figure 4:  Block diagram of the complete experimental setup, for testing it
with green blinking LED and natural radiation.

  1. 1.

A green LED light was attached to the photosensitive area of 3-mm $\times$
3-mm of the Hamamatsu Multi-Pixel Photon Counter S12572-100P, and operated
inside a black box as follows: 1) with the LED blinking at frequency
1Hz–100kHz, with exponential decay waveform or pulse waveform, and 2) with the
LED turned off.

  2. 2.

The detection material was attached, by its polished end, to the
photosensitive area of 3-mm $\times$ 3-mm of the Hamamatsu Multi-Pixel Photon
Counter S12572-100P, outside the black box, and exposed to natural radiation,
see figure 4.

##  4 Results from feeding and reading-out electronic board characterization

We present the results from the characterization of the electronic board.

###  4.1 Transmission coefficient

In figure 5, we show the results of the transmission coefficient of the
feeding and reading-out electronic board as a function of the injected signal
frequency.

Figure 5:  Left: transmission coefficient as a function of the frequency
between 100 Hz to 10 kHz; right: transmission coefficient as a function of the
frequency between 10 kHz to 1 MHz; the two figures correspond to feeding and
reading-out electronic board; a linear fit is superimposed.

On the left side, we plot from 100 Hz to 10 kHz; on the right, from 10 kHz to
1 MHz. We include the linear fit parameters and the $\chi^{2}$ per dof (the
number of degrees of freedom), p0 (the Y-axis intercept, which is the average
transmission coefficient of the feeding and reading-out electronic board), and
p1 (the slope). The p0 values are 0.82$\pm$0.01 and 0.72$\pm$0.01 for 100 Hz
to 10 kHz and 10 kHz to 1 MHz, respectively; on average, it is 0.77$\pm$0.01;
the p1’s are near zero. These results are used for transmission correction and
calibration.

###  4.2 Phase shift

In figure 6, we show the results of the phase shift measurements on the
feeding and reading-out electronic board as function of the frequency of the
injected signal.

Figure 6:  Phase shift measurements vs frequency for 100 Hz to 1 MHz from
feeding and reading-out electronic board.

We plot from 100 Hz to 1 MHz (199 measurements); at frequencies near to 8 kHz,
there are two values for the phase shift less than two degrees; at 370 kHz and
600 kHz, there are four values for the phase shift higher than one degree and
less than two degrees, not distinguished; at 800 kHz, there are four values
for the phase shift higher than four degrees and less than six degrees, not
distinguished. Usually, the phase shift is almost zero degrees and not
depending on the frequency; from 199 measurements, only ten were found with
values greater than one degree and less than six degrees at frequencies of 10
kHz, 370 kHz, and 600 kHz. These results do no compromise the function of the
feeding and reading-out electronic board. Signals are not filtered.

###  4.3 Transit time

The measured transit time was (741.72$\pm$82.80) ps. This value indicates
high-speed electronic board, which can read out high-speed signals and avoid
superposition of signals.

##  5 Results from digitizing-electronic-board characterization

We present the results from the characterization of the electronic board.

###  5.1 Digitizing efficiency error

In table 1, we show the results of the digitizing efficiency error —using eq.
(2.1)— of the digitizing-electronic board as function of the input frequency.
At low frequencies (1 Hz up to 10 Hz), the $eff$ is zero for the electronic
board and the function generator. At intermediate frequencies (100 Hz up to 1
MHz), it is slightly increased. Similar dependence is observed at higher
frequencies (100 kHz up to 1 MHz).

Table 1:  Digitizing efficiency error (%) for the digitizing-electronic board and for the Tektronix function generator AFG3101, as function of frequency. | Frequency
---
| 1 Hz
---
| 10 Hz
---
| 100 Hz
---
| 1 kHz
---
| 10 kHz
---
| 100 kHz
---
| 1 MHz
---
| Electronic board
---
$eff$ ($\times 10^{-3}$ %)
| 0.00
---
| 0.00
---
| 1.11
---
| 1.28
---
| 1.27
---
| 1.26
---
| 1.24
---
| Function generator
---
$eff$ ($\times 10^{-3}$ %)
| 0.00
---
| 0.00
---
| 1.11
---
| 1.11
---
| 1.12
---
| 1.14
---
| 1.12
---

The average $eff$ was 0.88$\times 10^{-3}$ %; for this work, it is negligible.

###  5.2 Digitizing efficiency

In table 2, we show the results of the digitizing efficiency —using eq. (2.1)
and subtracting it from 100 %— of the digitizing-electronic board as function
of the input frequency. At 1 Hz to 10 Hz, the digitizing efficiency is 100 %
for the electronic board and the function generator. It is slightly
decremented (0.01 %) at frequencies 100 Hz to 1 MHz.

Table 2:  Digitizing efficiency (%) for the digitizing-electronic board and the Tektronix function generator AFG3101, as function of incoming signal frequency. | Frequency
---
| 1 Hz
---
| 10 Hz
---
| 100 Hz
---
| 1 kHz
---
| 10 kHz
---
| 100 kHz
---
| 1 MHz
---
| Electronic
---
board
| 100.00
---
| 100.00
---
| 99.99
---
| 99.99
---
| 99.99
---
| 99.99
---
| 99.99
---
| Function
---
generator
| 100.00
---
| 100.00
---
| 99.99
---
| 99.99
---
| 99.99
---
| 99.99
---
| 99.99
---

The average digitizing efficiency was 99.99 %.

###  5.3 Digitizing time

The digitizing time is the sum of the propagation delays of the ADCMP582
comparator chip (U1) and MC10ELT21DG differential PECL to TTL translator chip
(U2), 180 ps and 3.5 ns, respectively [12, 13]. The measured digitizing time
was (2.96$\pm$0.13) ns.

##  6 Results from the experimental setup

The Hamamatsu Multi-Pixel Photon Counter S12572-100P operation range frequency
was measured to be from 1 Hz to 10 kHz, and to be from 1 Hz to 100 kHz, using
a green LED light pulsed with a decay exponential waveform voltage and using a
pulse waveform with a duty cycle of 1.5 %, respectively. We found no dark
counts or spurious signals when the controlled LED light is turn off.

Exposing to natural radiation the detection material attached to Hamamatsu
Multi-Pixel Photon Counter S12572-100P, we got these results: The noise signal
was $\pm$20 mVPk-Pk; the analog signal is positive exponential decay, with an
amplitude of $\sim$280 mVPk-Pk, a rise time of $\sim$13 ns, and a fall time of
$\sim$249.60 ns.

The output digital pulse signal has $\sim$3.8 VPk-Pk of amplitude, which is
close to the operating voltage of the LVTTL family. In addition, we detected a
positive overshooting at $+$2 Vdc and negative overshooting at $-$3 Vdc, both
less than $\sim$10 ns width. This overshoot does not affect the cRIO
measurements because the positive overshoot is less than $+$3.3 Vdc (LVTTL
family) and less than 25 ns of width (operation rate of cRIO); see the figure
7; The NI-9402 C module (from the cRIO) discriminates the negative overshoot.

Figure 7:  Waveform from experimental setup using threshold voltage at $+$60
mVdc and feeding voltage at $+$75 Vdc; the analog signal is the red waveform;
the digital signal, the blue waveform.

##  7 Conclusions

We presented the design, construction, characterization, and testing of an
one-channel electronic module for the Hamamatsu Multi-Pixel Photon Counter
S12572-100P.

We have evaluated transmission coefficient, phase shift, and transit time of
feeding and reading-out electronic board. The average transmission coefficient
is 0.77$\pm$0.01. The phase shift is almost zero degrees and independent on
the frequency, but were randomly produced at some frequencies; at frequencies
near 7.90 kHz and 8.00 kHz, the phase shift is $+$1.13 degrees and $-$1.71
degrees, respectively; at frequencies near 370 kHz and 600 kHz, the phase
shift is $+$1.184 degrees and $+$1.171 degrees, respectively; at frequencies
between 780 kHz and 810 kHz, there are four values for the phase shift, the
first two with $-$5.17 degrees and the rest with values of $-$5.11 degrees.
The measured transit time is (741.72$\pm$82.80) ps.

We have evaluated digitizing efficiency error ($eff$), digitizing efficiency,
and digitizing time of digitizing-electronic board. The average $eff$ is
0.88$\times 10^{-3}$ %. The digitizing efficiency is 99.99 %. The digitizing
time is (2.96$\pm$0.13) ns.

From the experimental setup used to evaluate the Hamamatsu Multi-Pixel Photon
Counter S12572-100P, the digital signal corresponds perfectly to the analog
signal; the characteristic results of the analog signal obtained by Hamamatsu
Multi-Pixel Photon Counter S12572-100P and its electronic module are very
similar to the characteristic results published by the Hamamatsu Multi-Pixel
Photon Counter S12572-100P datasheet.

The transmission coefficient can be used to correct the analog output signal
of the electronic board. The phase shift is low and negligible for this work.
The transit time indicates a high-speed electronic module able to read high-
speed signals and avoid the superposition of signals and errors when
transmitted by other electronic circuit states.

The digitizing efficiency error is low and negligible for this work. The
digitizing efficiency indicates that the design and manufacture of this
electronic board are reliable. The digitizing time measured indicates
discrimination or conversion of a very-narrow analog signal, and its value is
lower than the one reported by manufacturers.

An interesting aspect of this electronic module is that any other MPPC series
or model can be used with minor changes in the feeding and reading-out
electronic board. The production cost is approximately 68 USD (not including
the Hamamatsu Multi-Pixel Photon Counter S12572-100P and metal shielding
costs).

We manufactured, tested, and run a set of ten feeding and reading-out
electronic boards and five digitizing-electronic boards, the obtained results
were similar.

The MPPC module developed is a robust, high-speed, and low-cost that can be
used in high-energy physics applications like cosmic ray and neutrino
detectors, dark matter, calorimeters, and Cherenkov telescopes, among others.

## References

  * [1] Hamamatsu, “Datasheet.” https://www.hamamatsu.com/content/dam/hamamatsu-photonics/sites/documents/99_SALES_LIBRARY/ssd/mppc_kapd9008e.pdf.
  * [2] S. Gundacker and A. Heering, _The silicon photomultiplier: fundamentals and applications of a modern solid-state photon detector_ , _Physics in Medicine Biology_ 65 (2020) 17TR01.
  * [3] Hamamatsu, “Datasheet.” http://laboratoriodeparticulaselementales.blogspot.com/p/documentos.html.
  * [4] Hamamatsu, “Si detectors for high energy particle.” https://www.hamamatsu.com/content/dam/hamamatsu-photonics/sites/documents/99_SALES_LIBRARY/ssd/high_energy_kspd9002e.pdf, 2021\.
  * [5] M. Yokoyama, T. Nakaya, S. Gomi, A. Minamino, N. Nagai, K. Nitta et al., _Application of hamamatsu mppcs to t2k neutrino detectors_ , _Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment_ 610 (2009) 128.
  * [6] “Ni crio-9025 intelligent real-time embedded controller for compactrio.” http://www.ni.com/pdf/manuals/375490d.pdf, October, 2015.
  * [7] “Ni crio-9111/9112/9113/9114/9116/9118 compactrio reconfigurable embedded chassis.” http://www.ni.com/pdf/manuals/375079e.pdf, April, 2016.
  * [8] “Ni 9402, 4 dio, lvttl, bidirectional, 55 ns.” http://www.ni.com/pdf/manuals/374614a_02.pdf, January, 2016.
  * [9] “Tds2000c and tds1000c-edu series digital storage oscilloscopes user manual.” https://download.tek.com/manual/TDS2000C-and-TDS1000C-EDU-Oscilloscope-User-Manual-EN.pdf, April 11, 2013.
  * [10] D.J. Mowbray, “Use of an oscilloscope, webside.” https://www.yumpu.com/en/document/view/18116200/use-of-an-oscilloscope, July, 2003.
  * [11] R. Coughlin and F. Driscoll, _Operational Amplifiers and Linear Integrated Circuits_ , Prentice-Hall, Inc., Upper Saddle River, New Jersey, USA, 07458. (2001).
  * [12] A. Devices, “Datasheet.” http://www.analog.com/media/en/technical-documentation/data-sheets/ADCMP580_581_582.pdf, 2016\.
  * [13] O. Semiconductor, “Datasheet.” https://www.mouser.com/datasheet/2/308/1/MC10ELT21_D-2315134.pdf, August, 2015.