CREAM

Collaboration:

Location of the experiment: Ballon flights from Antarctica and/or North Pole

National Responsible: P.S. Marrocchesi(Pi)

1. Goal of the experiment

CREAM (Cosmic Ray Energetics And Mass) is designed to perform a direct measurement of cosmic ray composition over the elemental range from proton to iron to the supernova energy scale of 1015 eV in a series of balloon flights using the new Ultra Long Duration Balloon (ULDB) capability under development by NASA. ULDB flights are designed to last from 60 to 100 days each.  The goal is to observe cosmic ray spectral features and/or abundance changes that might signify a limit to supernova acceleration

More on the experiment…

2.

Activities during 2002

During 2002, a R&D program relative to the calorimeter was carried out within the framework of the
WCAL project,  which ended in December 2002.  A Tungsten-SciFi prototype calorimeter 16 RL thick was built and successfully tested at CERN in August 2002 with beam energies ranging between 5 and 100 GeV.  Details on the calorimeter construction and beam test results can be found in the proceedings of the 8th Topical Seminar on Innovative Particle and Radiation Detectors - Siena (21-24 Oct 2002).
During the first half of 2002 we built the S2 hodoscope for the first flight of the CREAM instrument (CREAM-1). The hodoscope was installed in the calorimeter module at the July 2002 beam test at CERN and then shipped to the US for the final integration in CREAM-1.

Milestones 2003:

Commissioning and integration of the S2 hodoscope in CREAM-1 (for the first flight)

30-06-2003

Construction and beam test of the calorimeter for CREAM-2 (for the second flight)

30-12-2003

 

3. INFN contribution to the experiment in terms of manpower and financial support

·        Manpower:13 researchers (6.6 FTE)

·        Budget for the Year 2003:   2.1% of the CSNII budget for 2003

4. Publications in referred journals (in 2002): 1

5. Conference talks (in 2002): 4

6. Number of undergraduate and doctoral thesis on the experiment: 2

7. Leadership roles and primary responsibilities in the experiment:

Coordination of the S2 hodoscope for the first flight; Coordination of the Calorimeter for the second flight

8. Innovative instruments

     The particle charge (Z) will be measured by a timing-based charge detector and a pixelated silicon detector to minimize the effect of backscatter from the calorimeter. Energy measurements will be performed by a transition radiation detector (TRD) for Z > 3 and a sampling tungsten/scintillator calorimeter for Z >= 1, allowing inflight cross calibration of the two detectors.  The Tungsten-SciFi calorimeter (preceded by a Carbon target) implements an innovative technique of light splitting to achieve a very large dynamic range (energy measurements up to 1000 TeV).

9. Competing experiments

The Advanced Thin Ionization Calorimeter (ATIC) Balloon experiment.  Designed to measure the composition and energy spectra of cosmic rays from ~10 GeV to near 100 TeV, the ATIC instrument has a smaller acceptance than CREAM and a limited exposure (each LDB flight is limited to a maximum of 3 weeks).

10. International committee which has reviewed the experiment

Goddard Space Flight Center (GSFC) Wallops Flight Facility (WFF) Balloon Program Office; NASA