Form 8

Research Result Report
ICRR Inter-University Research Program 2023
Research Subject: New Photogrammetry Calibration for Super-Kamiokande andHyper-Kamiokande
Principal Investigator:

Patrick de Perio, Kavli IPMU, University of Tokyo

Participating Researchers:

Xiaoyue Li (TRIUMF), Rhea Gaur (TRIUMF),

Ka Ming Tsui (IPMU), César Jesus-Valls (IPMU), Junjie Xia (IPMU)
Deepak Tiwari (University of Regina / JSPS Summer)
Summary of Research Result：
A demonstration of geometry
reconstruction was performed with
~6 rings of barrel PMTs (648 intotal) in 2021 and a set of PMTs
(588 in total) neighbouring thevertical column of light injectors(LIs) in 2023. The (now graduated)
MSc student developed a new
manual-labeling software, which asmall team at IPMU and ILANCE
used to identify all the PMTs inthese LI photos. We started fromthe previously traditionally (notML) detected feature points andmodified them to ensure theiraccurate positioning on PMT
dynodes and bolts, then labeled
based on position relative to the LIs. The reconstruction code was updated to accept
these inputs and produce the measured PMT positions in the right figure (boltpositions omitted for clarity). A quick check showed a
σ = 1.1 cm (0.5 cm) radial (tangential) spread from a line fitted to one column of PMTs.
Further analysis of these results is needed. The challenge to label the rest of thedetector (without any visual references) remains. The fitting code was updated tooutput the fitted errors on each point to give a measure of the significance of any
deviation from the design geometry, but a complete systematic error analysis is stillto do. The seed (design) geometry in the fitter was updated to the realistic polygonalstructure (rather than cylindrical) with the help of theOkayama group, resulting in improved agreement with themeasurement, reducing the mean of the residuals from 1.3
to 0.9 cm. Eventually, the measurement will be used in theSK (Geant4) and WCSim (for Hyper-K, IWCD, and WCTE)
detector simulations, in which we now implemented
variation of the detector shape.
Following last year’s successful pressure tests at Lab-F in
Kamioka, 8 camera housings were constructed in Canada(one example in left figure) and begun calibrating for
deployment in WCTE at CERN this summer. After WCTE,
these housings will be used in the IWCD.

Form 8The Institute of Industrial Science(IIS) Ocean Engineering Basin(OEB), a 50x10x5m pool was rented
for 1 week, in part by these funds.
The remove operated vehicle (ROV)
absolutepositioning
systems:
onboard sonar, short baseline
ultrasonic transmitter & receivers(U-GPS), and a Doppler Velocity
Log (DVL), were purchased by
TRIUMF and this ICRR grant for
R&D, and tested on the wellcalibrated (mm level) translation
and rotation platform of the OEB,
shown in the left figure. The
analysis is ongoing, and a
preliminary result shows the U-GPSand DVL systems tracking themotions well.

The deep-sea red lamp thatwas purchased last year wastested with an R14374 PMT,
which unfortunately showed a
39% increase in count rate
when turning on the lamp (20%with a 720 nm cut-off filter),indicating a significant overlap
in wavelength of the light and
PMT’s quantum efficiency.
This was also indicated bymeasurements of the lamp
spectrum, including the 720nm filter, overlayed with thetypical 3” PMT sensitivity
curve in the left figure. Thismeans we should not use this lamp while the detector is on, but can still be used in
WCTE or IWCD when the detector is off (to minimize PMT activation compared towhite light).

整理番号A24