FPI WP Status

5 Nov. 2008 Univ. Padova, Physics Department, Plenary Meeting

FPI WP Status

Short summaryR. Mirzoyan

MPI Munich


FPI

• FPI WP includes the front part of the imaging camera: PMTs (light sensors), pixels, clusters, HV power supply, postamplifier, light guide system, protective/sealing window, the camera mechanics and its junction with the mount of the telescope

• FPI is working in a very close contact with the ELEC WP


PMT

• Select the most probable size of PMTs (with the help of other WPs: MC, Mount & Mirror) and start development work with companies

• Make a request to the CTA consortium to look for possibilities to allocate some finances for the development work in th years 2009-2010

Min. request: 160.-k€/1 yearMax. request: 400.-k€/2 years • The major goals: try to achieve a peak

PDE ≥ 40 % (PDE = QE x Charge Coll. Eff.)

Afterpulsing ≤ (0.03 – 0.01) %


PMTs

• Offers from major PMT manufacturers are obtained. We plan to check in the coming ~4 months some ~ 10 type PMTs of 1-2 inch size at least from 2 manufacturers, in 2 locationsSiPM

• Evaluate SiPMs from all possible manufacturers that have the promise to become a candidate sensor for CTA. Pay attention to cost, cost/performance issues. Ongoing study


Light Guides

• Which type of production, costs, ease of manufacturing, automatic production, reflectivity, angular acceptance, ageing, ...

• Single ones or plates of LGs• Lining or evaporating technique


Protective plexiglas window

• The thickness, uv transmission, minimize the reflection by antireflective coating:

• Ask CTA for some funds for the last task; the development scale seem to be

30-50.-k€ (this could reduce the reflectivity from (8-

10) % down to ~ 1 % level)


Slow control aspects of FPI

• What shall be read out and controlled, how frequent ?

– Single rates above a given threshold– Anode currents– Calibration pulses– Check HV, dc-dc converter supply,

control voltages, temperature, humidity, ...


Mechanics

• Weight optimisation, cost issues.• Temperature (stab. ?) and related issues• Humidity and temperature sensors• Sectioning• Protection from dust, humidity (plex. window)• LED system for pointing• Camera doors (lids)• Pop-up mylar foil, maybe also reflective target


Interaction with other WPs

• MC: inputs on pixel size(s), FoV of the camera(s)

• Optics: light spot sizes over the camera area, LG and its concentration

• Mount: camera weight constraints • Try to provide for the other WPs cost

estimates on the pixel, also including the mechanics =>

• Together narrow the range of candidate PMTs, start development work with the industries

FPI WP Status

Documents

Transcript of FPI WP Status