OPERA

THE COLLABORATION

- Belgium: IIHE (ULB-VUB), Brussels
- Bulgaria: Sofia University, Sofia
- China: IHEP, Beijing; Shandong University, Tsinan (Shantung)
- Croatia: Rudjer Boskovic Institute (IRB), Zagreb
- France: LAPP, IN2P3-CNRS and Université de Savoie, Annecy; LAL, IN2P3-CNRS and Université Paris-Sud, Orsay; IPNL, IN2P3-CNRS and Université C. Bernard Lyon I, Villeurbanne; IRES, IN2P3-CNRS and and Université Louis Pasteur, Strasbourg
- Germany: Humboldt University, Berlin; Märkische Fachhochschule FB Elektrotechnik, Hagen; Hamburg University, Hamburg; Münster University, Münster; Fachbereich Physik der Universitaet Rostock, Rostock
- Israel: Israeli group c/o Technion, Haifa
- Italy: INFN and Bari University, INFN and Bologna University, INFN and L' Aquila University, INFN Laboratori Nazionali del Gran Sasso, ,INFN Laboratori Nazionali di Frascati, INFN and Naples "Federico II" University, INFN and Padova University, INFN and Rome "La Sapienza" University, INFN and Salerno University,
- Japan: Aichi Educational University, Aichi; Toho University, Funabashi; Kobe University, Kobe; Nagoya University, Nagoya; Utsunomiya University, Utsunomiya
- Russia: JINR, Dubna; INR, Moscow; ITEP, Moscow
- Switzerland: Bern University, Bern; Neuchatel University, Neuchatel
- Turkey: METU, Ankara

Laboratory/Beam: Gran Sasso National Laboratory/CNGS

National Responsible: M.T. Muciaccia (Bari)

1. GOAL OF THE EXPERIMENT

The OPERA experiment is designed for the direct observation of nt appearance from nm --> nt oscillations in the CNGS long baseline beam from the CERN SPS to the INFN Gran Sasso Laboratory.

More on the experiment...

2.

Activities during 2002

Due to CERN financial difficulties, the activity in 2002 was seriously limited: orders were frozen and relevant changes in the detector design were introduced. The CNGS (CERN to Gran Sasso) beam start-up was postponed to 2006. In spring 2002, the experiment was assigned the Hall C at LNGS.

The Collaboration firmly faced the situation: in order to save money, the number of spectrometers was reduced to 2. This choice results in a 10% reduction of the detector mass with negligible effects on the experiment sensitivity.

The new technical drawing was defined. In November 2002, orders ware unfrozen. The mounting of the first spectrometer is planned for January 2003.

The new project of the mechanical structure was developed according to anti-seismic standards.

Full-scale prototypes of brick support structures (walls) were assembled and tested.

Tests on RPC prototypes were performed at CERN and Gran Sasso. The mass-production of the RPC's of the first magnet has already started.

The brick structure was finalised and the use of additional emulsion foils (changeable sheets) was included in the final design in order to reduce the scanning load and improve the brick finding efficiency. In spring 2002, the first stock of OPERA-like emulsion foils was produced by FUJI. Technical tests were performed to check emulsion quality. Momentum reconstruction by Multiple Coulomb Scattering and particle identification were studied by exposing bricks to CERN pion/electron beams and the intercalibration of foils was investigated by means of cosmic ray exposures at Gran Sasso.

The R&D activity aiming at the development of a new generation of high-speed (20cm2/h ) fully automated systems has been carried on in Italy and the first prototype of a microscope with a scanning speed of about 10cm2/h was completed. This prototype is now being used to tune the tracking algorithms. In parallel, the S-UTS is being developed in Japan.

Due to the cancellation of the OPERA CERN group, the sharing of tasks was re-defined and Italian and Japanese groups took the responsibility of the brick assembly machine (BAM).

Extensive tests on packing and vacuum keeping were performed at CERN.

A document containing detailed technical requirements was prepared and European companies were contacted for commissioning.

A production line for the Target Tracker, consisting of plastic scintillator strips and multianode PMT's, is already operational in Strasbourg and a new line is foreseen for 2003 (enough to fulfil OPERA requests).

The construction of a dedicate hall for drift tube production is in progress in Hamburg.

25 t of lead plates were commissioned in order to test the production process, the quality of plates and the organisation of lead transportation to Gran Sasso.

The following achievements have been obtained: by the Italian groups:

- Start RPC production for spectrometers (100%)
- Start installation of the first spectrometer (80%)
- Engineering design of the support mechanical structure (100%)
- Definition of the design of the BAM(50%)
- Construction of prototype high speed microscope for scanning station (100%)

Milestones 2003

Commissioning of the wall construction | 31-12-2003
Start installation of the first spectrometer, assuming that the order can be formally placed by end 2002 | 31-12-2003
Commissioning of the BAM construction | 31-12-2003
Construction of the final final version of the automatic scanning system | 31-12-2003
RPC complete production for the first supermodule | 31-12-2003
Finalize procedure for brick intercalibration | 31-12-2003

3.INFN CONTRIBUTION TO THE EXPERIMENT IN TERMS OF MANPOWER AND FINANCIAL SUPPORT

Manpower:

About 50 researchers from the Italian groups contributed to the OPERA activities in 2002 (about 40 FTE). We profited from the technical support from the Sezioni INFN: technical design (LNF, Napoli, Padova), emulsion and brick handling (Bari, Bologna, Napoli, Roma, Salerno), electronic detectors (LNF, Padova), electronics design (Napoli, LNF, Padova, LNGS). Local support was also given to the R&D activities on automatic scanning (Bari, Bologna, Napoli, Roma, Salerno). A contribution was given by the technical services of the LNGS for setting up the emulsion laboratory at Gran Sasso, the cosmic ray station for emulsion alignment and to perform radioactivity measurements on the site.

About 10 dedicated technicians have been involved (5 FTE) in addition to about 90 man-year from general technical workshops (Sezioni INFN).

Budget for the Year 2003: 15.5% of the CSNII total budget

4. PUBLICATIONS IN REFEREED JOURNALS (Year 2002) : 2

5. CONFERENCE TALKS (Year 2002): 6

6. NUMBER OF UNDERGRADUATE AND DOCTORAL THESIS ON THE EXPERIMENT

In relation to the Italian groups:

15 Laurea Thesis in Physics completed or in progress; 9 Doctoral Thesis.

7. LEADERSHIP ROLES IN THE EXPERIMENT

- Spokesperson: Yves Declais;
- CB Chairperson : L. Votano
- Gran Sasso Technical Coordinator: M. Spinetti;

8.INNOVATIVE INSTRUMENTS

Innovative instrumentation is being developed in two main fields related to the operation of the detector at Gran Sasso and to the analysis of the emulsion films. Specialised industry has been involved.

Automation:

- computer controlled systems for emulsion brick packing and handling;
- automatic devices for high speed and high precision movements (microscope mechanics).

High definition image analysis:

- new generation CCD cameras and CMOS sensors with high frame rate and high image quality;
- new multi-processor frame grabbers for on-line image analysis.

9. COMPETING EXPERIMENTS

Other planned, approved or running long baseline neutrino oscillation experiments with the aim of studying the atmospheric neutrino deficit with terrestrial experiments are:

- Super-Kamiokande in Japan with the K2K beam from KEK;
- MINOS in Minnesota with the NuMI beam from FERMILAB;
- ICARUS at Gran Sasso with the CNGS beam from CERN.

K2K is running and can perform a disappearance search for neutrino oscillations, as well as MINOS, starting from 2004. ICARUS can study nm-nt oscillations with an appearance experiment based on the kinematical selection of the t signal. OPERA will be the only experiment able to directly identify the t decay topology through the detection of its (short) track with the emulsion films. The experiment will start running in 2006.

10.INTERNATIONAL COMMITTEES WHICH HAVE REVIEWED THE EXPERIMENT

The OPERA Letters of Intent and the Experiment Proposal (which can be found on the web: http://opera.web.cern.ch/opera/ )have been reviewed by the CERN Super Proto Synchrotron Committee (SPSC) and by the Gran Sasso Laboratory Scientific Committee (LNGSSC).