The 9th Asian Triangle Heavy-Ion Conference (ATHIC 2023)

Evaluation of a high-speed transmission cable for sPHENIX-INTT silicon detector

25 Apr 2023, 16:20

20m

Multi-Purpose Studio, 2nd Floor (JMS Aster Plaza)

Poster Experimental techniques and future programs Poster Session

Speaker

TOMOYA KATO (Rikkyo University(for the sPHENIX-INTT collaboration))

Description

The sPHENIX experiment at Brookhaven National Laboratory (BNL) is a next-generation experiment equipped with a large solid angle detector to detect jets and precisely measure QGP properties. sPHENIX's INTT detector is a strip-type silicon detector that is positioned 7~10 cm from the collision point. The signal transmission cable of the INTT detector requires the development of a conversion cable.
The first prototype of a conversion cable employing FPC technology was manufactured. However, during the testing process, it was found that the FPC cables were not flexible enough and that the signal attenuation exceeded the acceptable range. In order to overcome these problems, the micro coaxial cable (μ-coax) was employed as an alternative solution. It’s diameter is 0.04 mm and a signal line width of 0.25 mm. While its mechanical and electric features satisfies the requirements, it is well known that the insulator material, i.e. PFA is susceptible against radiation. Therefore, this study evaluates the transmission performance of the fabricated μ-coax and the radiation resistance of the μ-coax when installed in the sPHENIX experiment.
　The transmission performance is evaluated by three measurements; 1) s-parameter, 2) impedance (TDR), 3) eye-diagram measurements. Attempted data collection from silicon ladder using daisy-chained cables and μ-coax
To evaluate radiation resistance, we first estimated expected radiation dose at the location of conversion cables to be located during sPHENIX operation. As a result, we estimated the expected radiation dose around the region where cables are installed is 1.5×10^11 Equivalent Neutrons. The RIKEN neutron irradiation system was used to irradiate μ-coax with higher than expected radiation dose. Neutron dosage was calculated using indium foil, which emits γ-rays proportionate to neutrons received. Transmission performance was re-evaluated after neutron irradiation to assess radiation effects and resistance.