# Presentation: 698758

## Slide 1

## Slide 2

## Slide 3

## Slide 4

## Slide 5

## (S, Q fibers 0.8 mm  )

- Filling fraction = 31.7%; Sampling fraction = 2.1%

- (S, Q fibers 0.8 mm ****** )

## Effective radius 162 mm (0.8 int, 8 rM )

- Effective radius 162 mm (0.8 ******int**, 8 **r****M** )

## Slide 8

## Slide 9

## Slide 10

## DREAM energy resolution (for jets):

- Need to test larger calorimeter for full containment;
- Test also effects of magnetic fields and finer sampling;
- Simulation being tuned to the beam test data.
- 20-25%/√E  with finer sampling and BE fluctuations measured

## Slide 12

## 1.  Electrons and photons limited by photo-statistics; study dual readout of single PbWO4 crystal.

- 2.  Binding energy loss fluctuations next biggest contributor to energy resolution; study readout of MeV neutrons from hadronic shower.
- 3.  Readout to compact B-insensitive photo-converter;  study  SiPM with integrated electronics, FADC, etc.

**4****th**** Calorimeter Plans**

##   Techniques to separate light from Cherenkov and

-    scintillation:
-   - time structure and directionality of light.
-   Measuring MeV neutrons in showers:
-  - special SciFi (non-H, Boron-loaded)
-  - time spectrum
-  - Birk’s parameter/PSD
-   Crystal EM section in front of triple-readout module
-   Multipixel Photon Counter/Si-PM for readout

## Slide 15

##   Separation of Scintillation and 

**Cerenkov Light with a single PMT**** **

_**a. Method using the time structure**_

**Time structure of light signals.**

- Scintillator and Cerenkov light pulses
- have distinctly different time spectra.
- Applying Fast-Slow discrimination
- the two components can be selected;
- This technique will be also useful for
- neutron selection as well.

## Slide 17

- Slope *dL/dt* measures C/S

## Slide 19

## Measuring MeV neutrons

- Velocity of MeV n is   ~ 0.05 c
- Scintillation light from  np→np scatters comes late;
- neutrons fill a larger volume;
- This method misses early neutrons

- t(ns) →

- by time

## “hydrogen-rich” vs “hydrogen-poor” SciFi 

- Hydrogenous scintillating fiber measures protons from np→np scatters;
- A second scintillating non-hydrogenous fiber measures all charged particles, but no protons from np scatters.

- Pacific Northwest Laboratory works on these;

**Lithium-loaded or Boron-loaded fibers**

**Birk’s constant:** parameterizes the reduction in detectable ionization from heavily ionizing particles (essentially due to recombination)
- Some of these materials are difficult liquids

##  Crystal (PbWO4) EM section 

**in front of triple-readout module**

-   Dual (scintillation+Cerenkov) readout: idea tested at CERN.   “*Separation of Scintillation and Cerenkov Light in an Optical Calorimeter”,* **Nucl.Instrum.Meth.**A550:185-200,2005
-   Physics gain: excellent EM energy resolution (statistical term very small), excellent spatial resolution with small transverse crystal size.
-   Dual-readout yields correct hadronic energy deposited in EM section (1/2 of all hadrons interact in EM section).
-   Use Multi-Pixel Photon Counters (MPPC/SiPM)

## Slide 23

## Slide 24

## Slide 25

## Backup slides

## Slide 27

## Slide 28

## Slide 29

## .......

- - Test beam at CERN summer 2006

- After 2005 shutdown DREAM ready (and eager) to resume test beam

- - New collaborators are joining:
- .......
- Korea
- Italy ( Lecce, Messina, Pavia, Roma, Trieste / Udine)
- .......

- - Many ideas and techniques to explore, many suggestions/advices

**Gaining momentum, hopefully support also....**