News from CERN

The selection board for the new RP physicist replacing Jan Tuyn (once he is retired) was held and resulted in the recruitment of Dr. Doris Forkel-Wirth. Doris is a well known and excellent physicist in the ISOLDE (Isotope Separator On Line Device) Collaboration; in fact she has been the coordinator and showed that she managed to tame a whole bunch of researchers always asking the maximum beam time for their own experiment. This feature of her personality and her deep knowledge of what could go wrong in the Isotope Separator On Line made her the ideal replacement for Jan. She will take up her job in October thus assuring a good overlap period before Jan will definitively leave the Group next year.

The damage caused by the fire which struck the SPS (Superprotonsynchroton) exactly three months ago and mentioned in CERN's contribution in the last IARPE Newsletter was repaired in record time. Management decided to cancel this year's heavy ion runs in favour of extending the proton period until mid-November. This step saved the about two weeks of beam time previously granted to the CERN European Reference radiation Facility (CERF: means in French "stag". CERN actually keeps a herd of deer in a fenced area near the CERF installation).

CERF has been used for the calibration and intercomparison of dosimetric devices in high energy stray radiation since 1993 and is partially supported by the European Commission, in the framework of a research program for the assessment of radiation exposure at civil flight altitudes. The reference fields are, in fact, sufficiently similar to the cosmic ray field encountered at 10-20 km altitude such that instrumentation can be tested at CERN and subsequently be used for in-flights measurements on aircrafts.

Following the measurement campaigns in the years 1993-1996, two are scheduled this year (in August and in September). Several institutions from all over Europe participate (last year we also had colleagues from Japan), using a number of different techniques, both active and passive, such as multisphere systems, different models of rem counters, different types of Tissue Equivalent Proportional Counters (TEPCs), newly developed electronic dosemeters for neutrons, nuclear emulsions, track-etch detectors, superheated drop bubble detectors, albedo dosimeters, etc. Among the users during the present campaign is a strong group from PTB (The national standards institute of Germany) testing a set of precision Bonner spheres (Drs. Wittstock and Alevra), a coincidence-anticoincidence TEPC to discriminate charged and neutral particles in the radiation field (Dr. Schrewe) and an electronic personal neutron dosemeter (Drs. Luszik-Bhadra and Matzke). Furthermore, users from GSI in Darmstadt and the Universities of Saarbruecken and Prague participate in this run in August.

The facility that has been described extensively in the past so please consult a recent paper on further details [C. Birattari, A. Ferrari, M. Höfert, T. Otto, T. Rancati and M. Silari, Recent results at the CERN-EC high energy reference field facility, Proceedings of the Third Specialists' Meeting on Shielding Aspects of Accelerators, Targets and Irradiation Facilities (SATIF3), Sendai (Japan), 12-13 May 1997 (in press)]. The results of measurements of the radiation fields with a TEPC spectrometer agree well with the latest Monte Carlo calculations performed with the FLUKA code by A. Ferrari and colleagues. Very good agreement is also found between the Monte Carlo results and experimental data taken by a set of Bonner spheres.

The extension of the proton period until mid-November in the SPS will deprive us of the additional radioactive cooling from which we profited in previous years; the lead ion runs in recent years did not contribute to the activation of the machine, but caused however higher neutron doses in experimental areas.

Not much progress has been made as far as RP is concerned in the LHC (Large Hadron Collider) project. CERN is still waiting for the papers of the Environmental Impact Study (including radiation) to be distributed within France, where then they must be studied before reactions are expected. On the other hand, the answers to the queries concerning the Safety Report in the framework of the INB (Installation Nuclear de Base) procedure for LEP (Large Electron Positron collider) are progressing smoothly as far as radiation protection is concerned.

It appears more and more probable that INFN (Instituto Nazionale de la Fisica Nucleare) and CERN will build a proton target facility to send neutrinos to the Gran Sasso detectors south of Rome. This will take three times the annual rate of protons used up to now for the present West Area Neutrino Facility which has given us in the Radiation Protection Group so much trouble and heart-ache. Graham Stevenson and Marco Silari have the thankless task of ensuring that the new facility gives us less trouble than the present one.

Physics at lower energies is not forgotten at CERN: Following the decision to close the LEAR (Low Energy Antiproton Ring) antiproton program, there were strong requests from the user community to continue certain experiments with low energy antiprotons, e.g. for antihydrogen production. For this reason a simplified solution was found in the transformation of the existing AC (antiproton collector) installation into the AD (antiproton decelerator) in which antiprotons are decelerated to 100 MeV/c. Experiments will be installed inside the AC ring which caused some problems of access and shielding. The AD will be operational in 1999.

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