NeuLAND - FAIR

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Number of detected photons (1”): 9835 Direct coupling of the PM to the scintillator. Number of detected photons (1.5”): 21728 Number of detected photons (1”): 10227 Pyramidal light guide. Number of detected photons (1.5”): 24146 Number of detected photons (1”): 10525 Spherical light guide. Number of detected photons (1.5”): 21052 Number of detected photons (1”): 10229 Parabolic light guide. Number of detected photons (1.5”): 23067 50 Figure 4.10.: Shapes of light guides and photon tracks.
Counts 600 500 400 300 200 100 without light guide light guide: pyramidal light guide: spherical light guide: parabolic 0 5 6 7 8 9 10 20 Time (ns) Counts 900 800 700 600 500 400 300 200 100 without light guide light guide: pyramidal light guide: spherical light guide: parabolic 0 5 6 7 8 9 10 20 Time (ns) Figure 4.11.: Arrival time photons from simulations with different light guide shapes, displayed on the left-hand side for an entrance window of the photomultiplier of 1 inch, and of 1.5 inch in the figure at the right-hand side. 4.5. Scintillator Studies of Full-Size NeuLAND The detailed simulations shown in the following subsections were performed using the R 3 BRoot framework. As reference the most important parameters are again summarized here. Within R 3 BRoot the TGEANT3 interface was selected, including the interaction option GCalor for low-energy neutrons. The dimensions of the NeuLAND detector in these simulations are defined very similar to the proposed final detector design, see section 5. Only the light guides are omitted within this study due to the high computational effort of optical photon tracking, see section 4.4. The detector submodules are 250 cm long and have a cross section of 5 × 5 cm 2 . Twenty submodules are grouped in planes of 250 × 250 cm 2 and the detector depth of 3 m is built up from 60 planes, which are stacked alternating with horizontal and vertical paddles. Light quenching for protons was taken into account using Birk’s relation [Bir-64]. The transport of the resulting light from the position of production to the readout positions of the scintillator bars takes into account the scintillator time response and the light attenuation length of the bar. Energy thresholds were set to approximately 160 keV for both read-out sides, including a small variation to simulate typical behaviour of jitter in read-out electronics. An integration time of approximately 200 ns is applied for the collection of the light output. The time of each hit is derived from the mean time of the both readout times of the bar. Unless specified differently a time resolution of 150 ps was assumed. The adaption factor for the total energy deposit, obtained from the R 3 BRoot comparison to the neutron calibration data of LAND, see section 4.1.2, was applied for the description of energy loss in NeuLAND accordingly. 1 Figure 4.12 shows exemplarily a typical event, displayed in a NeuLAND side view. 1 Although the mismatch in the total energy deposit spectra is most likely originating from a malfunctioning absolute energy calibration in the experiment, we take the reduction of total energy loss for further simulations as a safety margin into account. 51
Page 1 and 2: FAIR/NUSTAR/R 3 B/TDR NeuLAND Techn
Page 3 and 4: Germany EMMI and FIAS: Enrico Fiori
Page 5 and 6: INR Moscow: Alexander Botvina Russi
Page 7 and 8: Contents Executive Summary 11 1. In
Page 9: B.7. MRPC Solution using Glass as C
Page 12 and 13: Apart from the excellent energy res
Page 14 and 15: processes in the universe, such as
Page 16 and 17: decaying into 24 O plus 4 neutrons
Page 19 and 20: 2. Physics Scenarios: Requirements
Page 21 and 22: e studied at R 3 B at FAIR include
Page 23 and 24: all theoretical calculations predic
Page 25 and 26: at the surface of the nucleus. The
Page 27 and 28: the evolution of fission channels (
Page 29 and 30: 3. Summary of NeuLAND Prototype Res
Page 31 and 32: counts 70 60 50 40 30 20 10 0 15 15
Page 33 and 34: Figure 3.4.: Shown is the time reso
Page 35 and 36: 4. Monte Carlo Simulations Within t
Page 37 and 38: normalized counts normalized counts
Page 39 and 40: GEANT3 interface. Here, we compare
Page 41 and 42: Counts 1000 900 800 700 600 500 400
Page 43 and 44: counts 5 10 4 10 3 10 2 10 10 LAND
Page 45 and 46: incident neutron fully active detec
Page 47 and 48: investigated. Three values for the
Page 49: spectrum, absorption length, refrac
Page 53 and 54: Since, as discussed above, several
Page 55 and 56: events 800 600 400 200 0 0 200 400
Page 57 and 58: clusters N 100 50 0 0 500 1000 1500
Page 59 and 60: In the following section we discuss
Page 61 and 62: events 15000 10000 5000 input outpu
Page 63 and 64: events 2000 1500 1000 500 σ = 15 k
Page 65 and 66: 5. Technical Specifications and Des
Page 67 and 68: construction, or for subsequent rep
Page 69 and 70: positioning of 50 submodules mounti
Page 71 and 72: Figure 5.6.: Detector frame with fi
Page 73 and 74: 5.4. Peripheral Systems 5.4.1. Read
Page 75 and 76: Figure 5.12.: The photo shows the T
Page 77: 6. Radiation Environment and Safety
Page 81 and 82: 8. Calibration 8.1. Calibration wit
Page 83 and 84: Figure 8.3.: ToF distribution in 10
Page 85: Figure 8.4.: Event display for seve
Page 89 and 90: 10. Installation procedure, its Tim
Page 91: 11. Cost and Funding 11.1. Cost Est
Page 94 and 95: The timeline for milestone 1 includ
Page 96 and 97: 96 2. Sample Tests Random samples o
Page 98 and 99: PNPI St. Petersburg: G.D. Alkhazov,
Page 100 and 101:
HV 1.$ mm 2$ mm 0+$1-2)-2'.%/ 5%4'.
Page 102 and 103:
Beamline Be exit window P 6 P 3 P 4
Page 104 and 105:
B.3. Design Issues Addressed with 4
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Time [ns] Counts 41 40 39 2200 2000
Page 108 and 109:
Efficiency 100 80 60 40 20 0 7.5 8
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200 AMeV, Erel = 100 keV emitted %
Page 112 and 113:
B.7. MRPC Solution using Glass as C
Page 114 and 115:
114
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[Bot-04] S. Botvina andI.N. Mishust
Page 118 and 119:
[Lip-03] C. Lippmann, PhD Thesis, U
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NeuLAND - FAIR

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