Performance of a neutron polarimeter to measure the electric form factor of the neutron

T. Eden; R. Madey; W. M. Zhang; B. D. Anderson; A. R. Baldwin; J. M. Cameron; J. M. Finn; C. C. Foster; J. J. Kelly; S. Kowalski; R. Lourie; P. Markowitz; B. Ni; P. J. Pella; J. Schambach; M. Spraker; E. Steinfelds; E. J. Stephenson; J. W. Watson

doi:10.1016/0168-9002(94)91327-7

Performance of a neutron polarimeter to measure the electric form factor of the neutron

T. Eden, R. Madey, W. M. Zhang, B. D. Anderson, A. R. Baldwin, J. M. Cameron, J. M. Finn, C. C. Foster, J. J. Kelly, S. Kowalski, R. Lourie, P. Markowitz, B. Ni, P. J. Pella, J. Schambach, M. Spraker, E. Steinfelds, E. J. Stephenson, J. W. Watson

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12 Scopus citations

Abstract

We measured the analyzing power and the efficiency of a neutron polarimeter that was designed and constructed to measure the neutron electric form factorG_Eⁿ. The measurement was carried out at the Indiana University Cyclotron Facility (IUCF) with the ¹⁴C(p,n)¹⁴N reaction at a proton beamenergy of 138.4 MeV. The analyzing power, 〈A_y〉, averaged over the acceptance of the polarimeter is typically 0.44±0.02_-0.03^+0.04 at a neutron energy of 135 MeV. With a lead-steel wall, consisting of 4 in. of lead sandwiched between two 1 3 8-in. steel plates, ahead of the polarimeter, the average analyzing power is the same within statistics, namely, 〈A_y〉 = 0.43 ± 0.02_-0.03^+0.04. The large systematic uncertainty quoted here is dominated by an uncertainty from the inability at the time of the experiment of measuring the longitudinal polarization component of the sideways polarized protons; this systematic uncertainty can be reduced significantly to 0.02 in any future calibration at the IUCF. In each case, the efficiency of the polarimeter is about 0.26% for 135 MeV neutrons at a pulse-height threshold of 4 MeV equivalent electron energy (MeVee) on the front detectors and 10 MeVee on the rear detectors. This analysis reveals a small analyzing power from the carbon in the front-analyzer detectors.

Original language	English
Pages (from-to)	432-441
Number of pages	10
Journal	Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
Volume	338
Issue number	2-3
DOIs	https://doi.org/10.1016/0168-9002(94)91327-7
State	Published - Jan 15 1994
Externally published	Yes

Funding

This research was supported in part by the National Science Foundation under grants PHY #88-02392 and PHY #91-070604 . One of us (P .J .P .) acknowledges support from the Research Corporation.

Funders	Funder number
National Science Foundation	91-070604, PHY #88-02392
Research Corporation for Science Advancement

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10.1016/0168-9002(94)91327-7

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Eden, T., Madey, R., Zhang, W. M., Anderson, B. D., Baldwin, A. R., Cameron, J. M., Finn, J. M., Foster, C. C., Kelly, J. J., Kowalski, S., Lourie, R., Markowitz, P., Ni, B., Pella, P. J., Schambach, J., Spraker, M., Steinfelds, E., Stephenson, E. J., & Watson, J. W. (1994). Performance of a neutron polarimeter to measure the electric form factor of the neutron. Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 338(2-3), 432-441. https://doi.org/10.1016/0168-9002(94)91327-7

@article{b00acfde4b154d63b1cb5aafab6d535d,

title = "Performance of a neutron polarimeter to measure the electric form factor of the neutron",

abstract = "We measured the analyzing power and the efficiency of a neutron polarimeter that was designed and constructed to measure the neutron electric form factorGEn. The measurement was carried out at the Indiana University Cyclotron Facility (IUCF) with the 14C(p,n)14N reaction at a proton beamenergy of 138.4 MeV. The analyzing power, 〈Ay〉, averaged over the acceptance of the polarimeter is typically 0.44±0.02-0.03+0.04 at a neutron energy of 135 MeV. With a lead-steel wall, consisting of 4 in. of lead sandwiched between two 1 3 8-in. steel plates, ahead of the polarimeter, the average analyzing power is the same within statistics, namely, 〈Ay〉 = 0.43 ± 0.02-0.03+0.04. The large systematic uncertainty quoted here is dominated by an uncertainty from the inability at the time of the experiment of measuring the longitudinal polarization component of the sideways polarized protons; this systematic uncertainty can be reduced significantly to 0.02 in any future calibration at the IUCF. In each case, the efficiency of the polarimeter is about 0.26% for 135 MeV neutrons at a pulse-height threshold of 4 MeV equivalent electron energy (MeVee) on the front detectors and 10 MeVee on the rear detectors. This analysis reveals a small analyzing power from the carbon in the front-analyzer detectors.",

author = "T. Eden and R. Madey and Zhang, {W. M.} and Anderson, {B. D.} and Baldwin, {A. R.} and Cameron, {J. M.} and Finn, {J. M.} and Foster, {C. C.} and Kelly, {J. J.} and S. Kowalski and R. Lourie and P. Markowitz and B. Ni and Pella, {P. J.} and J. Schambach and M. Spraker and E. Steinfelds and Stephenson, {E. J.} and Watson, {J. W.}",

year = "1994",

month = jan,

day = "15",

doi = "10.1016/0168-9002(94)91327-7",

language = "English",

volume = "338",

pages = "432--441",

journal = "Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment",

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Eden, T, Madey, R, Zhang, WM, Anderson, BD, Baldwin, AR, Cameron, JM, Finn, JM, Foster, CC, Kelly, JJ, Kowalski, S, Lourie, R, Markowitz, P, Ni, B, Pella, PJ, Schambach, J, Spraker, M, Steinfelds, E, Stephenson, EJ & Watson, JW 1994, 'Performance of a neutron polarimeter to measure the electric form factor of the neutron', Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, vol. 338, no. 2-3, pp. 432-441. https://doi.org/10.1016/0168-9002(94)91327-7

Performance of a neutron polarimeter to measure the electric form factor of the neutron. / Eden, T.; Madey, R.; Zhang, W. M. et al.
In: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 338, No. 2-3, 15.01.1994, p. 432-441.

Research output: Contribution to journal › Article › peer-review

TY - JOUR

T1 - Performance of a neutron polarimeter to measure the electric form factor of the neutron

AU - Eden, T.

AU - Madey, R.

AU - Zhang, W. M.

AU - Anderson, B. D.

AU - Baldwin, A. R.

AU - Cameron, J. M.

AU - Finn, J. M.

AU - Foster, C. C.

AU - Kelly, J. J.

AU - Kowalski, S.

AU - Lourie, R.

AU - Markowitz, P.

AU - Ni, B.

AU - Pella, P. J.

AU - Schambach, J.

AU - Spraker, M.

AU - Steinfelds, E.

AU - Stephenson, E. J.

AU - Watson, J. W.

PY - 1994/1/15

Y1 - 1994/1/15

N2 - We measured the analyzing power and the efficiency of a neutron polarimeter that was designed and constructed to measure the neutron electric form factorGEn. The measurement was carried out at the Indiana University Cyclotron Facility (IUCF) with the 14C(p,n)14N reaction at a proton beamenergy of 138.4 MeV. The analyzing power, 〈Ay〉, averaged over the acceptance of the polarimeter is typically 0.44±0.02-0.03+0.04 at a neutron energy of 135 MeV. With a lead-steel wall, consisting of 4 in. of lead sandwiched between two 1 3 8-in. steel plates, ahead of the polarimeter, the average analyzing power is the same within statistics, namely, 〈Ay〉 = 0.43 ± 0.02-0.03+0.04. The large systematic uncertainty quoted here is dominated by an uncertainty from the inability at the time of the experiment of measuring the longitudinal polarization component of the sideways polarized protons; this systematic uncertainty can be reduced significantly to 0.02 in any future calibration at the IUCF. In each case, the efficiency of the polarimeter is about 0.26% for 135 MeV neutrons at a pulse-height threshold of 4 MeV equivalent electron energy (MeVee) on the front detectors and 10 MeVee on the rear detectors. This analysis reveals a small analyzing power from the carbon in the front-analyzer detectors.

AB - We measured the analyzing power and the efficiency of a neutron polarimeter that was designed and constructed to measure the neutron electric form factorGEn. The measurement was carried out at the Indiana University Cyclotron Facility (IUCF) with the 14C(p,n)14N reaction at a proton beamenergy of 138.4 MeV. The analyzing power, 〈Ay〉, averaged over the acceptance of the polarimeter is typically 0.44±0.02-0.03+0.04 at a neutron energy of 135 MeV. With a lead-steel wall, consisting of 4 in. of lead sandwiched between two 1 3 8-in. steel plates, ahead of the polarimeter, the average analyzing power is the same within statistics, namely, 〈Ay〉 = 0.43 ± 0.02-0.03+0.04. The large systematic uncertainty quoted here is dominated by an uncertainty from the inability at the time of the experiment of measuring the longitudinal polarization component of the sideways polarized protons; this systematic uncertainty can be reduced significantly to 0.02 in any future calibration at the IUCF. In each case, the efficiency of the polarimeter is about 0.26% for 135 MeV neutrons at a pulse-height threshold of 4 MeV equivalent electron energy (MeVee) on the front detectors and 10 MeVee on the rear detectors. This analysis reveals a small analyzing power from the carbon in the front-analyzer detectors.

UR - http://www.scopus.com/inward/record.url?scp=0028320390&partnerID=8YFLogxK

U2 - 10.1016/0168-9002(94)91327-7

DO - 10.1016/0168-9002(94)91327-7

M3 - Article

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SN - 0168-9002

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JF - Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment

IS - 2-3

ER -

Performance of a neutron polarimeter to measure the electric form factor of the neutron

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