Speaker
Mr.
Angel Perea Martinez
(IEM/CSIC)
Description
The use of increasingly segmented silicon detectors in nuclear reaction experiments poses challenging
constraints on the design of the experimental chambers, as several detectors and related pieces
should be placed in a extremely reduced space, attending to the experimental positions required by
the physics of the experiment. At the same time, a large number of signals (usually in excess of 100)
must be routed out of the chamber to the preamplifiers sitting outside.
Traditionally this has been done with coaxial feedthroughs, but they introduce several problems of
their own: sealing o-rings are prone to leaks and the solderings usually get brittle after several
uses, leading to shortcuts or missing channels. Besides, placement of the detectors is also
compromised as the bulky of 32+ pole cables (plus jacket) put unwanted stresses on them. Achieving
the required position precision for the detectors is sometimes also hard.
We present several related solutions to those problems using Printed Circuit Boards (PCBs) both for
placement and feedthrough. Use of multilayered PCBs allows for large improvement in feedthrough
density (taken as number of signals fed-through per unit area), usually several times the achieved
with the standard coaxial feedthroughs, at a fraction of the cost. In an alternative design, the use
of PCBs all the way to the preamp, minimizes both the cable use and the number of connectors,
restricting them only to the inner part of the chamber, where they are effectively isolated from
RF noise. Signals come out shielded by ground planes all the way to the preamp.
Placement is also efectively achieved by plugging the detectors directly on a card. Using a two cards
stack arrangement, different setups can be achieved by switching cards without altering the preamp
layout and calibrations.
We've succesfully tested a chamber design for 11Be experiment at TRIUMF (Canada), and developed a
second chamber for an incoming experiment at Jyvaskyla (Finland). Both designs are presented in
the current talk.
| Oral or poster presentation | Oral |
|---|
Primary author
Mr.
Angel Perea Martinez
(IEM/CSIC)
Co-author
Prof.
Olof Tengblad
(IEM/CSIC)
