RIKEN Accel. Prog. Rep. 50 (2017)

Ⅱ-4. Hadron Physics

Development of a prototype silicon tracking detector for thesPHENIX experiment
∗1
∗1
∗1
∗1
∗1∗2
∗1∗2Y.
Y.
T.
Y.
E. Mannel,∗3 H.
Y. Yamaguchi,
Yamaguchi,∗1
Y. Akiba,Akiba,∗1T. Hachiya,
Hachiya,∗1Y. Kawashima,
Kawashima,∗1,∗2
H. Masuda,
Masuda,∗1,∗2
G. Mitsuka,∗1∗1∗1∗2
Nakagawa,∗1
D. Nemoto,
Nemoto,∗1,∗2
I.I. Nakagawa,D.
and R. Nouicer∗3Fig. 1. A prototype module of INTT with 320 μm-thick Sisensors.

FVTX chip on the HDI is shown in Fig. 2. A clear
correlation between calibration pulse amplitude andADC values can be seen and all channels look working.
It has been conﬁrmed that the Si sensors and FPHX
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Pulse amplitude

ADC

Quark Gluon Plasma (QGP) is an extreme hot anddense QCD matter where quarks and gluons are released from conﬁnement inside hadrons and it is believed to have existed in the early universe. The studyof QGP gives a rich knowledge on not only how ouruniverse has been formed but fundamental features ofQCD in a high dense and high temperature environment.
The sPHENIX experiment is scheduled to start datataking from 2021 at the Relativistic Heavy Ion Collider(RHIC) to reveal the medium properties of QGP, andthe tracking system of the sPHENIX detector consistsof the monolithic active pixel sensors (MAPS), the intermediate silicon tracking detector (INTT), and thetime projection chamber (TPC) from the inside to theoutside. We have a responsibility for construction ofINTT which has an important role to realize good capabilities on:

760

6505• track reconstruction by association of MAPS andTPC hit information• single collision vertex ﬁnding with a high collisionrate
We have inherited the readout system and basic ideaof the module structure for the forward vertex detector (FVTX)1) as a subsystem of the PHENIX detector
to minimize R&D eﬀorts of INTT so that INTT construction can be completed in time for start-up of thesPHENIX experiment. Therefore, we need to understand how a whole readout system of INTT including
the inherited devices works using a prototype module.
In this report, the current status of development of a
prototype module is reported.
The ﬁrst prototype modules of INTT have been assembled at BNL. Si sensors2) with thickness of 240
and 320 μm from HAMAMATSU Photonics K.K. areused for the prototype modules. Figure 1 shows theprototype module with 320 μm-thick Si sensors. Highdensity interconnect circuits (HDIs) are connected oneither side of the Si sensors and 10 FPHX chips aremounted on each HDI. The FPHX chip is originallydesigned as a pre-ampliﬁer for FVTX and contains 128channels. The Si sensors are mechanically separated atthe middle and the FPHX chips are wire-bonded to theSi sensors.
Tests of the prototype modules have been made using calibration pulses. The test result for a single∗1∗2∗3RIKEN Nishina Center
Department of Physics, Rikkyo University
Brookhaven National Laboratory- 116 -40

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Pulse amplitude80

100120Channel IDFig. 2. The correlation between calibration pulse amplitude and ADC values (Left) and reactions with the calibration pulses for all channels on a chip (Right).

chips can be assembled successfully on a HDI and awhole readout system works well with the prototype
modules.
New HDIs will be produced with an improved design to match an updated detector position conﬁguration soon and further tests with prototype modules arescheduled including cosmic ray measurements.
References
1) C. Aidala et al., NIM A 755, 44-61 (2014).
2) Y. Akiba et al., in this report.