SLIM

The Collaboration:

- Italy: Dipar.to di Fisica dell'Universita’ di Bologna and INFN; Dipar.ti di Fisica Sperimentale e Generale dell'Universita’ di Torino and INFN; Istituto TeSRE/CNR, Bologna.
- Bolivia: Laboratorio de Fisica Cosmica de Chacaltaya,UMSA, La Paz
- Canada: Centre for Subatomic Research, Univ. of Alberta.
- Pakistan: RPD, PINSTECH, P.O. Nilore, Islamabad.

Laboratory: Laboratorio de Fisica Cosmica de Chacaltaya, Bolivia.

National Responsible: L. Patrizii (Bo)

1. Goal of the experiment

The SLIM experiment is a new large area array ( 400 m2 ) of nuclear track detectors (CR39 and Makrofol) which searches for magnetic monopoles of intermediate masses (106 – 1010 GeV) and nuclearites (aggregates of quarks u, d, s and electrons) in cosmic rays. It is installed at the high altitude Laboratory of Chacaltaya (Bolivia) at 5230 m a.s.l. In four years of operation it will reach a sensitivity to a monopole flux at the level of the Parker bound (i.e. ~ 10-15 cm-2 s-1 sr-1).

More on the experiment...

2.

Activities during 2002

- Measurements of the neutron flux at Chacaltaya in the energy range 1-20 MeV (Slim Int. Memo 1/2002) and of the radon background
- Exposure of stacks of CR39+Makrofol foils and of SLIM-like modules to 1 A GeV Fe ions at BNL and to 30 A GeV Pb ions at Cern
- A new etching method was developed which greatly improves the quality of the CR39/Makrofol post-etched surface and reduces significantly the density of fake tracks (SLIM Int. Memo 2/2002).

The following achievements have been obtained:

- Environmental measurements at Chacaltaya, with special regard to the Rn-222 and neutron background (100 %)
- Analysis of about 30 sq m of the installed detector in order to estimate the background and the sensitivity (80 % (*))

(*) The analysis of 30 m2 of the installed detector is almost completed. The delay (the plan was to complete it by the end of 2002) was due to: 1) bureaucratic problems in bringing back the detector from Bolivia and 2) the etching Laboratory in Bologna was kept closed until the end of 2002 for the upgrading of the security system.

Milestones 2003

Detector calibrations | 31-07-2003
Analy sis of about 30 m2 of the installed detector in order to estimate the background and the sensitivity | 31-12-2003
Setting up of a new automatic fast scanning system | 31-12-2003

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

- Manpower: 12 researchers (4.2 FTE)
- Budget for the Year 2003: 0.2 % of the CSN2 budget for 2003

4. Publications in refereed journals (in 2002): 0

5. Number of conference talks (in 2002): 2

6. Number of undergraduate and doctoral thesis of the experiment 0

7. Leadership roles and primary responsibilities in the experiment

Spokesperson of the SLIM Collaboration is Dr. Laura Patrizii, from INFN Sezione di Bologna. The Bologna group is the leading group in the collaboration.

8. Innovative instruments

SLIM uses a very high quality CR39 polymer developed by the Bologna group in collaboration with the industry (Intercast Co., Parma). The company is now worldwide known as one of the few producers in the world of such detector.

9. Competive experiment

No other experiment of this kind (large area and high altitude) is in operation or planned.

10. International committee which has reviewed the experiment

None