Realistic requirements from R3B program

In-beam tests of Demonstrators (no TRD yet)

Decisions on: Readout device, Forward cap detectors ( Detector manufacturing program, Formulation of acceptance test)

CALIFA LU DEMONSTRATOR ARRAY

V. Avdeichikov, P. Golubev, B. Jakobsson, June 2008

Readout of CsI(Tl) – photodiodes?

+ PDs do not need specific temperature or voltage stability precausions

What about resolution and threshold?

With existing PA/PD

significantly worse energy resolution

high threshold ~100 keV

Can the proper combination of PA and PD solve the problem?

black points: calculated, open (1.0 nA), closed (2.0 nA). red points: measured with PAs eV5091 and PHOS

The gamma energy resolution depends very much on the PD noise level.

A low-capacity (15 pF) PD with low current (< 1 nA) can give a resolution close to what an APD can provide.

We should order a PD with these parameters now if ......................

the R3B and/or EXL programmes or at least a substantial part of these programmes can live with a threshold of ~100 keV.

remember

the proton performance

some parts of the programmes

may have a stronger wish to

use CALIFA/EGPA to identify

light fragments

(fragmentation, spallation, multifragmentation .....)

Other items that the LU group wrestles with are:

- How to optimize gain corrected summing of gamma signals

- How to optimize the LO uniformity in a practical way

- The response function non-linearity in CsI(Tl)

- Large scale production and its control (certification) mechanisms

- Production of 210 mm CsI(Tl) detectors as option for La – crystals

about which you can read in the submitted report (pdf file) by V. Avdeichikov and in our (two) previous video meeting reports

-Writing a TSR report which may be useful for the TDR (BJ)

- Preparing in-beam tests (proposals to be discussed in Tech. Boards)

- Planning a test station in Kharkov(Dubna, VA – producer not chosen yet)