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. | last2=Baumann Baumann| first2=T. | last3=Thoennessen | first3=M. | last4=Brown Brown| first4=J. | last5=DeYoung | first5=P. | last6=Finck | first6=J. | last7=Hinnefeld Hinnefeld| first7=J. | last8=Howes | first8=R. | last9=Kemper Kemper| first9=K. | last10=Pancella | first10=P. | last11=Peaslee | first11=G. | last12=Rogers 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 | bibcode=2003NIMPA.505...33L | display-authors=3}}</ref><ref>{{citation | last1=Baumann | first1=T. | last2=Boike | first2=J. | last3=Brown Brown| first3=J. | last4=Bullinger | first4=M. | last5=Bychoswki | first5=J. P. | last6=Clark 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 Grant| first12=A. | last13=Hinnefeld | first13=J. | last14=Hitt | first14=G. W. | last15=Howes | first15=R. H. | last16=Isselhardt Isselhardt| first16=B. | last17=Kemper | first17=K. W. | last18=Longacre | first18=J. | last19=Lu | first19=Y. | last20=Luther 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 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 Walker| first36=N. | date=May 2005 | doi=10.1016/j.nima.2004.12.020 | issue=2–3 | journal=Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment | pages=517–527 517–527| title=Construction of a modular large-area neutron detector for the NSCL | volume=543 | bibcode=2005NIMPA.543..517B | 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. | last2=Volya | first2=A. | editor1-last=Woehr | editor1-first=A. | editor2-last=Aprahamian | editor2-first=A. | contribution=Continuum Shell Model, Reactions and Giant Resonances | doi=10.1063/1.2187905 | pages=493–497 493–497| 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 Prestemon| first1=S. | last2=Bird | first2=M. D. | last3=Crook | first3=D. G. | last4=DeKamp DeKamp| first4=J. C. | last5=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 Applied Superconductivity | pages=1721–1724 | title=Structural design and analysis of a compact sweeper magnet for nuclear physics | volume=11 | bibcode=2001ITAS...11.1721P | display-authors=3}}</ref><ref>{{citation | last1=Toth | first1=J. | last2=Bird | first2=M. D. | last3=Miller | first3=J. R. | last4=Prestemon Prestemon| first4=S. | last5=DeKamp | first5=J. C. | last6=Morris | first6=L. | last7=Thoennessen | first7=M. | last8=Zeller 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 12| bibcode=2002ITAS...12..341T | 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 | title=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.
