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 1. Name of Experiment:
    Rösti I, II and III.

 2. Purpose and Phenomena Tested:
    Space distribution of hadron and low-energy neutron fluences and absorbed doses
    in the cascades induced in iron and lead dumps irradiated by high-energy hadron

 3. Description of Source and Experimental Configuration:
    The experiments Rösti I (Ref. [1]) and III (Ref. [3]) were performed at the 
    H6 secondary beam in the North Experimental Area of the CERN SPS (Super Proton
    Synchrotron). The beam consisted of positive hadrons (2/3 protons and 1/3
    positive pions) with a momentum of 200 GeV/c.  The beam had a gaussian profile
    with standard deviations of the projected horizontal and vertical beam profile
    distributions equal to 1.2 and 0.9 cm respectively.

    Experiment Rösti II (Ref. [2]) took place at an extracted beam of the CERN PS
    (Proton Synchrotron). The beam consisted of protons of 24 GeV/c momentum,
    with a Gaussian profile of standard deviation 0.13 cm in both the horizontal
    and the vertical direction.

    In Rösti I and II the target was a dump made of twenty 5 cm thick, 30x30 cm square 
    iron plates. The density of the iron was 7.86 +/- 0.02 g/cm3. 
    The plates were welded to an iron framework with gaps of 0.7 cm between the plates. 
    Extra detector slots were provided in front of the first plate (slot 0) and behind 
    the last plate (slot 20). A sketch of the dump is given in Fig. 1.
    The beams were incident on the centre of the first absorber slab.
    Aluminium plates, 0.4 cm thick, 24 cm wide and 30 cm high, were inserted into each 
    slot excepted slot 9, which was left empty. Aluminium disks of varying sizes were
    punched out of the plates at different radial distances from the center and  several
    of them were used as activation detectors. Other detectors (RPL glasses inside
    polyethylene capsules of 0.8 cm internal diameter, sulphur and indium disks) were 
    placed in the remaining holes. A sketch of a detector plate containing the aluminium
    samples is given in Fig. 2.

    In Rösti III the target was a dump made of twenty 5 cm thick, 50x50 cm square lead
    plates. The density of the lead was not measured. The lead composition was known
    to include a small amount of antimony (about 4%).
    The lead plates were bolted together with 0.8 cm gaps and placed on an iron
    support structure. A sketch of the dump is given in Fig. 3.
    The beam was incident on the first absorber slab 10 cm off-centre in the horizontal
    Activation detectors, mounted on aluminium plates 0.05 cm thick and with 50x50 cm 
    lateral dimensions, included aluminium, indium, sulphur and polyethylene disks.
    A slight azimuthal asymmetry around the nominal beam axis was found for the detectors
    with the highest activation threshold (but not for the others). The data reported
    for each radial distance are the aritmetic mean of different azimuthal detector

 4. Measurement System and Uncertainties:

    Activation detectors:

    115In(n,n')115mIn: indium disks of 1.0 cm diameter, 0.36 cm thick. 336 keV gammas 
        measured with a GeLi detector (absolute emission probability assumed = 46.7%)
    32S(n,p)32P: sulphur pellets of 2.3 cm diameter, 0.6 cm thick (thickness larger than 
        max. range of emitted beta particles). Betas were measured with a thin-window
        GM tube calibrated with a thick sulphur sample irradiated by neutrons from a
        PuBe source of known yield. Note that the original calibration, on which the
        results reported in Ref. [1], [2] and [3] were based, was later found incorrect.
        The numerical data available here are based on the new correct calibration.
    27Al(n,α)24Na: aluminium disk thickness 0.4 cm (Rösti I) or 0.05 cm (Rösti II 
        and III). Diameter: 1.0 to 3.0 cm (Rösti I & II), 1.0 to 4.0 cm (Rösti III)
        (increasing with radial distance). 2.754 MeV gammas were measured with a
        3"x3" NaI detector covered by a perspex cap.
    27Al(h,spall)18F: same disks and measuring apparatus as for the previous detector. 
        Annihilation photons of 0.511 MeV energy were measured by placing the disks
        between two sheets of perspex to ensure annihilation close to the source.
    12C(x,xn)11C: polyethylene disks 0.04 cm thick, with a 1.5 to 3.5 cm diameter
        (increasing with radial distance). These detectors were used only in the
        Rösti III experiment. The experimental data are not available.

    The measured activities were corrected for decay during and after the irradiation
    and during counting. A correction for non uniformity of the beam intensity was
    also made, based on several monitors. 

    The presence of the detectors was not considered in the calculational models 
    described in chapter 5. The aluminium detectors were cut out of the aluminium
    support plates, so only the plates must be considered. The other detectors were
    generally too small or of too small density to affect the development of the shower. 


    Schott-Jenner DOS2 Radiophotoluminescent dosimeters (RPL): glass rods 0.6 cm long
    and with a 0.1 cm diameter, read with a Toshiba FGD-6 reader. The composition is
    the following (in weight %): O-53.7%, P-33.4%, Al-4.6%, AG-3.7%, Li-3.7%, B-0.9%
    (A_eff ~ 19,  Z_eff ~ 10).
    These detectors were used only in the Rösti I and Rösti II experiments.

    A photo of a bare RPL and an irradiated one (braun) in the tube is shown here. 
    (An RPL becomes brown when it is irradiated to very high doses, which was never
    the case in these experiments. So, only the bare RPL in the picture corresponds to
    those used).
    In the simulations, the RPL geometry was not reproduced in detail (they were too
    small to get enough scoring statistics and to affect particle transport) but in a
    first phase dose was scored at their position, assuming a composition of 54% Oxygen
    and 46% "Aluminium equivalent". After some tests, it was found that scoring simply
    dose in aluminium was giving the same results (in the mixed fields of hadronic
    cascades, dose depends only very weakly on atomic number).

    The authors estimate that the results should have typical uncertainties of
    few percents, maximum 10%. Detectors were positioned by taping them
    with adhesive tape at positions known with the normal accuracy available
    with a measurement tape (typically about 1 mm, to be compared with detector 
    diameters of the order of 1 cm) 

 5. Description of Results and Analysis:
    The measured results are given in files rosti1.exp, rosti2.exp, rosti3.exp. 
    In the tables the standard deviations represent the spread of several measurements
    from different azimuthal detector positions.

    Calculations have been performed with FLUKA92 (Ref. [4], [5]) and with HETC88
    The following FLUKA92 input files prepared by J. Zazula are included here as a
    guide for the computational model development: 
    - fl24fe1.inp: FLUKA92 input for iron dump, 24 GeV/p (act. detectors)
    - fl24fe2.inp: FLUKA92 input for iron dump, 24 GeV/p (absorbed dose)
    - fl200fe1.inp: FLUKA92 input for iron dump, 200 GeV/h (act. detectors)
    - fl200fe2.inp: FLUKA92 input for iron dump, 200 GeV/h (absorbed dose)
    - fl-24pb.inp: FLUKA92 input for lead dump, 24 GeV/p (act. detectors)
    - fl-200pb.inp: FLUKA92 input for lead dump, 200 GeV/h (act. detectors)

    The input files are sufficient for a description of the geometry of the
    experiment, but the complete analysis included also several user routines 
    which are not included here.
    Unfortunately input files are not all consistent with each other. For
    instance some of the inputs for the Pb dump use a symmetrical geometry, while
    others describe more accurately the actual geometry, with the beam hitting 
    the dump off-center. Also the material composition may appear to be with or
    without a small amount of antimony.

    Note also that these files refer to a very old version of the code and are
    made available mainly to help in the geometry and material description.†Many
    defaults have now changed, and most settings should be revised, in particular
    those concerning the neutron cross sections (the 37-group library has been
    replaced by one with 72 groups).

 6. Special Features:

 7. Author/Organizer:

    G.R. Stevenson(*), A. Fassò(*), M. Bruzzi(**), C. Furetta(**), P. Giubellino(***), 
    M.C. Nielsen(*), P.G. Rancoita(**), J.S. Russ(#), R. Steni(***), L. Vismara(**) 

    A. Fassò(*), A. Ferrari(**), P.R. Sala(**), J. Ranft(##), G.R. Stevenson(*),
    J.M. Zazula(###)

     (*) Radiation Protection Group, CERN, CH-1211 Geneva 23 (Switzerland)
    (**) Istituto Nazionale di Fisica Nucleare, Milano (Italy)  
   (***) Istituto Nazionale di Fisica Nucleare, Torino (Italy) 
     (#) Carnegie-Mellon University, Pittsburgh, USA
    (##) Leipzig University, Germany
   (###) Institute of Nuclear Physics, Cracow, Poland

    Compiler of data for Sinbad:
    Alberto Fassò
    CERN-EP/AIP, CH-1211 Geneve 23 (Switzerland)
    e-mail: Alberto.Fasso@cern.ch

    Reviewer of compiled data:
    I. Kodeli
    OECD/NEA, 12 bd des Iles, 92130 Issy les Moulineaux, France
    e-mail: ivo.kodeli@oecd.org

 8. Availability:

 9. References:

    [1] J.S. Russ, G.R. Stevenson, A. Fassò, M.C. Nielsen, C. Furetta, P.G. Rancoita
        and L. Vismara, "Low-energy neutron measurements in an iron calorimeter
        structure irradiated by 200 GeV/c hadrons", CERN/TIS-RP/89-02 (1989) (*)
    [2] A. Fassò, G.R. Stevenson, M. Bruzzi, C. Furetta, P.G. Rancoita, P. Giubellino,
        R. Steni and J.S. Russ, "Measurements of low-energy neutrons in an iron
        calorimeter structure irradiated by 24 GeV/c protons", CERN/TIS-RP/90-19
        (1990) (*)
    [3] G.R. Stevenson, A. Fassò, C. Furetta, P.G. Rancoita, P. Giubellino, J.S. Russ
        and C. Bertrand, "Measurements of low-energy neutrons in a lead calorimeter 
        structure irradiated by 200 GeV/c hadrons", CERN/TIS-RP/91-11 (1991) (*)
    [4] A. Fassò, A. Ferrari, J. Ranft, P.R. Sala, G.R. Stevenson and J.M. Zazula,
        "FLUKA simulations of the Rösti experiments", CERN/TIS-RP/IR/92-44 (1992)
    [5] A. Fassò, A. Ferrari, J. Ranft, P.R. Sala, G.R. Stevenson and J.M. Zazula,
        "A comparison of FLUKA simulations with measurements of fluence and dose
        in calorimeter structures", Nucl. Instr. Meth. Phys. Res. A332, 459-468
    [6] R.G. Alsmiller, Jr., F.S. Alsmiller and O.W. Hermann, "The high-energy 
        transport code HETC88 and comparisons with experimental data", 
        Nucl. Instr. Meth. A295, 337-343 (1990)

    (*) Note that the 32S(n,p)32P activities and the dosimetric data reported in
        the original reports were corrected later due to new calibrations.

10. Data and Format:

     Filename     Size[bytes]   Content
    ------------- ------------ -------------
  1 rosti.htm          15,304  This information file
  2 rosti1.exp         10,484  Rosti I experimental data
  3 rosti2.exp         15,427  Rosti II experimental data
  4 rosti3.exp         20,205  Rosti III experimental data
  5 fl24fe1.inp        11,026  Input data for FLUKA92 code, iron dump, 24 GeV
  6 fl24fe2.inp        10,834  Input data for FLUKA92 code, iron dump, 24 GeV
  7 fl200fe1.inp       11,083  Input data for FLUKA92 code, iron dump, 200 GeV
  8 fl200fe2.inp       16,395  Input data for FLUKA92 code, iron dump, 200 GeV
  9 fl-24pb.inp        10,996  Input data for FLUKA92 code, lead dump, 24 GeV
 10 fl-200pb.inp        8,916  Input data for FLUKA92 code, lead dump, 200 GeV
 11 Fig-1.gif          22,970  Fig. 1: Sketch of the Rosti dump assemblies
 11 Fig-2.gif          13,088  Fig. 2: Al sample plate with Al detector sample positions
 11 Fig-3.gif          29,484  Fig. 3: Sketch of the Rosti III dump assembly
 12 rpl.jpg            35,361  Fig. 4: RPL dosimeter
 13 rosti1.sim          8,381  FLUKA92 simulation results for Rosti I
 14 rosti2.sim         12,247  FLUKA92 simulation results for Rosti II
 15 rosti3.sim         15,866  FLUKA92 simulation results for Rosti III
 16 rosti1.pdf      2,456,104  Reference
 17 rosti2.pdf      2,772,655  Reference
 18 rosti3.pdf      1,996,776  Reference
 19 rosti4.pdf        722,383  Reference
 20 rosti5.pdf      1,433,487  Reference

 SINBAD Benchmark Generation Date: 09/2002
 SINBAD Benchmark Last Update: 09/2002