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The Modular Neutron Array consists of 144 individual detector modules. Each module is based on a plastic [[scintillator]] measuring 10 cm by 10 cm by 200 cm. This scintillator bar is fitted with light guides on each end that direct the light into one [[photo-multiplier tube]] on each end. Each detector module is wrapped in a light-tight material, allowing the detector array to be arranged in different configurations.
In its original configuration, MoNA consisted of 9 vertical layers of 16 detectors stacked closely, having an active area of 2.0 m wide by 1.6 m tall. In its current arrangement (depicted in the adjacent image), it is stacked in four separate sections of 2, 2, 2, and 3 layers each, respectively, separated by spaces ranging from 0.5 to 0.8 meters. It measures both the position and time of neutron events with multiple-hit capability. The energy of a neutron is based on a time-of-flight measurement. This information together with the detected position of the neutron is used to construct the momentum vector of the neutrons.<ref>{{citation| last1= Luther| first1= B.| Lutherlast2= etBaumann| alfirst2= T.,| Nucllast3= Thoennessen| first3= M.| last4= Brown| first4= InstrJ.| Andlast5= MethodsDeYoung| A505,first5= 33P.| last6= Finck| first6= J.| last7= Hinnefeld| first7= J.| last8= Howes| first8= R.| last9= Kemper| first9= K.| last10= Pancella| first10= P.| last11= Peaslee| first11= G.| last12= Rogers| first12= W.| last13= Tabor| first13= S.| date= June (2003| doi= 10.1016/s0168-9002(03)01014-3| issue= 1-2| journal= Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment| pages= 33–35| title= MoNA—The Modular Neutron Array| volume= 505| display-authors=3}}</ref><ref>{{citation| last1= Baumann| first1= T.| Baumannlast2= etBoike| alfirst2= J.,| last3= Brown| first3= NuclJ.| Instrlast4= Bullinger| first4= M.| last5= Bychoswki| first5= J. P.| last6= Clark| first6= S.| last7= Daum| first7= K.| last8= DeYoung| first8= P. A.| last9= Evans| first9= J. V.| last10= Finck| first10= J.| last11= Frank| first11= N.| last12= Grant| first12= A.| last13= Hinnefeld| first13= J.| last14= Hitt| first14= G. W.| last15= Howes| first15= R. H.| last16= Isselhardt| first16= B.| last17= Kemper| first17= K. W.| last18= Longacre| first18= J.| last19= Lu| first19= Y.| last20= Luther| first20= B.| last21= Marley| first21= S. T.| last22= McCollum| first22= D.| last23= McDonald| first23= E.| last24= Onwuemene| first24= U.| last25= Pancella| first25= P. V.| last26= Peaslee| first26= G. F.| last27= Peters| first27= W. A.| last28= Rajabali| first28= M.| last29= Robertson| first29= J.| last30= Rogers| first30= W. F.| last31= Tabor| first31= S. L.| last32= Thoennessen| first32= M.| last33= Tryggestad| first33= E.| last34= Turner| first34= R. E.| last35= VanWylen| first35= P. J.| last36= Walker| first36= N.| date= May 2005| doi= 10.1016/j.nima.2004.12.020| issue= 2-3| journal= Nuclear Instruments Andand Methods A543in Physics Research, 517Section (2005)A: Accelerators, Spectrometers, Detectors and Associated Equipment| pages= 517–527| title= Construction of a modular large-area neutron detector for the NSCL| volume= 543| display-authors=3}}</ref>
The detection efficiency of MoNA is maximized for the high-beam velocities that are available at the NSCL's Coupled Cyclotron Facility (CCF). For neutrons ranging from 50 to 250 [[MeV]] in energy, it is designed to have an efficiency of up to 70% and expands the possible coincidence experiments with neutrons to measurements which were previously not feasible. The detector is used in combination with the Sweeper magnet<ref>{{citation| last1= Zelevinsky| first1= V.| Zelevinskylast2= andVolya| first2= A.| Volya,editor1-last= AIPWoehr| Confeditor1-first= A.| Proceditor2-last= Aprahamian| editor2-first= A.| 819contribution= Continuum Shell Model, 493Reactions and Giant Resonances| doi= 10.1063/1.2187905| pages= 493–497| publisher= American Institute of Physics| series= AIP Conference Proceedings| title= Capture Gamma-Ray Spectroscopy and Related Topics: 12th International Symposium, 4–9 September 2005, Notre Dame, Indiana| volume= 819| year= (2006)}}</ref><ref>{{citation| last1= Prestemon| first1= S.| Prestemonlast2= etBird| alfirst2= M., IEEED.| Translast3= Crook| first3= D. ApplG.| Supercondlast4= DeKamp| first4= J. 11,C.| 1721last5= Eyssa| first5= Y. M.| last6= Morris| first6= L.| last7= Thoennessen| first7= M.| last8= Zeller| first8= A.| date= March (2001)| doi= 10.1109/77.920115| issue= 1| journal= IEEE Transactions on Appliled Superconductivity| pages= 1721–1724| title= Structural design and analysis of a compact sweeper magnet for nuclear physics| volume= 11| display-authors=3}}</ref><ref>{{citation| last1= Toth| first1= J.| Tothlast2= etBird| alfirst2= M., IEEED.| Translast3= Miller| first3= J. ApplR.| Supercondlast4= Prestemon| first4= S.| 12,last5= 341DeKamp| first5= J. C.| last6= Morris| first6= L.| last7= Thoennessen| first7= M.| last8= Zeller| first8= A.| date= March (2002)| doi= 10.1109/tasc.2002.1018415| issue= 1| journal= IEEE Transactions on Applied Superconductivity| pages= 341–344| title= Final design of a compact sweeper magnet for nuclear physics| volume= 12| display-authors=3}}</ref><ref>{{citation |last1=Bird |first1=M. D. |last2=Bole |first2=S. |last3=Gundlach |first3=S. |last4=Kenney |first4=S. |last5=Miller |first5=J. |last6=Toth |first6=J. |last7=Zeller |first7=A. |date=June 2004 |doi=10.1109/tasc.2004.829720 |issue=2 |journal=IEEE Transactions on Applied Superconductivity |pages=564–567 |title=Cryostat Design and Fabrication for the NHMFL/NSCL Sweeper Magnet |volume=14 |bibcode=2004ITAS...14..564B |s2cid=34670655 |display-authors=3}}</ref><ref>{{citation |last1=Bird |first1=M. D. |last2=Kenney |first2=S. J. |last3=Toth |first3=J. |last4=Weijers |first4=H. W. |last5=DeKamp |first5=J. C. |last6=Thoennessen |first6=M. |last7=Zeller |first7=A. F. |date=June 2005 |doi=10.1109/tasc.2005.849553 |issue=2 |journal=IEEE Transactions on Applied Superconductivity |pages=1252–1254 |title=System Testing and Installation of the NHMFL/NSCL Sweeper Magnet |volume=15 |bibcode=2005ITAS...15.1252B |s2cid=24997693 |display-authors=3}}</ref> and its focal plane detectors for charged particles.<ref>{{citation| first=N.| last=Frank,| type=Ph.D. Thesis,| MSUtitle=Spectroscopy (of Neutron Unbound States in Neutron Rich Oxygen Isotopes| publisher=Michigan State University| year=2006)}}</ref> In addition, MoNA’s modular design allows it to be transported between experimental vaults and thus to be used in combination with the Sweeper magnet installed at the S800 magnet spectrograph.<ref>{{citation |last1=Bazin |first1=D. |last2=Caggiano |first2=J. A. |last3=Sherrill |first3=B. M. |last4=Yurkon |first4=J. |last5=Zeller |first5=A. |date=May 2003 |doi=10.1016/s0168-583x(02)02142-0 |journal=Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms |pages=629–633 |title=The S800 spectrograph |volume=204 |bibcode=2003NIMPB.204..629B |display-authors=3}}</ref> Due to its high-energy detection efficiency, this detector will be well suited for experiments with fast fragmentation beams at the proposed ISF.
== History ==
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