Ult ld N t I t t tiUltracold Neutron InstrumentationUltracold Neutron InstrumentationUltracold Neutron InstrumentationUltracold Neutron InstrumentationMarie Blatnik; Albert Young: For the UCNB CollaborationMarie Blatnik; Albert Young: For the UCNB CollaborationMarie Blatnik; Albert Young: For the UCNB Collaboration

L Al N ti l L b A d S dLos Alamos National Lab Andy SaundersLos Alamos National Lab, Andy SaundersyD t f El t i l d C t E i i W hk i C ll f E i iDept of Electrical and Computer Engineering Washkewicz College of EngineeringDept of Electrical and Computer Engineering, Washkewicz College of Engineering

Cleveland State UniversityMOTIVATIONMOTIVATION Cleveland State UniversityMOTIVATIONMOTIVATION Cleveland State UniversityPOLARIMETRYPOLARIMETRY DETECTIONDETECTIONPOLARIMETRYPOLARIMETRY DETECTIONDETECTION

A silver-plated 8-rung birdcage resonator was chosen for the spin-flipping design as a Figure 10: Below, p g g p pp g gcompromise between zeroth mode uniformity and decreased Q due to resistance

g ,photograph of acompromise between zeroth-mode uniformity and decreased Q due to resistance. photograph of a

lifi b dpreamplifier board,

i fliwith 6 channels,End

Figure 4: AFP spin-flipper. with 6 channels, with the FET in

dDrive g p pp

This birdcage resonator with the FET in DriveThis birdcage resonator produces a resonant liquid nitrogen.produces a resonant q g

Fi 1 Fsinusoidal standing wave

Figure 1: Feynman g

for neutron flipsdiagram of neutron beta

for neutron flips.Rung d g o eu o be

decay; Left: Two driving methodsg

Drivedecay; Left: Two driving methods.Right: End driven with an n → p + → p + ee + v+ veeRight: End-driven with a pp ee

no inter nucleon forces pick-up coil inside of the no inter-nucleon forces i f i h h d

p pstanding waveinterfere with the decay. standing wave.

Each rung’s impedance Zi = 1/(jωCi) + jωLi can be adjusted by tuning the self-inductanceEach rung s impedance Zi 1/(jωCi) jωLi can be adjusted by tuning the self inductance hi h dj t th t f f 1/(2 √LC)rung, which adjusts the resonant frequency f = 1/(2π√LC).

Constraints on the resonator are specified by the AFP magnet. The field is measured andConstraints on the resonator are specified by the AFP magnet. The field is measured and t k d ith th k t diti h b t B 0 977 T d 0 972 Ttweaked, with the peak resonant condition chosen as between B = 0.977 T and 0.972 T.PROBLEM DEFINITIONPROBLEM DEFINITIONPROBLEM DEFINITIONPROBLEM DEFINITION

Experiment Requirements:Experiment Requirements: Shim Coil Cycle Field Evolution Fit and Measured Field ProfilesShim Coil Cycle Field Evolution Fit and Measured Field Profiles SPICE simulations of the preamplifier help tune the component values to maximize SNR1. Well-characterized and efficient neutron polarization (+ and -). SPICE simulations of the preamplifier help tune the component values to maximize SNR and minimize rise time Cd 109 Bi 207 and Ce 139 were used to characterize the pixelsp ( ) and minimize rise time. Cd-109, Bi-207, and Ce-139 were used to characterize the pixels.

T] Simulated Preamp Transient Rd

[T Responsefor Various Silicon Capacitance

Fiel for Various Silicon Capacitance

c F

neti

agn

Ma

•1 pF = 16. ns Figure 11: Detector•10 pF = 18. ns20 F 20

Figure 11: Detector response peak: 65 6•20 pF = 20. ns

30 pF = 22 74 nsresponse peak: 65.6

MHBore Position [mm] •30 pF = 22.74 ns•40 pF = 25 235 ns

MHz[ ] •40 pF = 25.235 ns

15 2Figure 5: The field profile is monotonicallyFigure 2: Diagram of the AFP magnet. Spin manipulation is Figure 6: Each shim coil response was ~> 15.2 nsFigure 5: The field profile is monotonically decreasing for the field corresponding to the spin

g g g p pperformed with this magnet which contains one main coil for the

Figure 6: Each shim coil response wasindividually mapped as a basis for adecreasing for the field corresponding to the spin-performed with this magnet, which contains one main coil for the

l i i fi ld (7 T) d th i fli i fi ld ( 1 T) d 10individually mapped as a basis for a

The cadmium spectrum suggests that the protons will resolve in the silicon and the noiseflipper frequency (red line), but not acceptable polarizing field (7 T) and the spin-flipping field (~1 T), and 10 superposition calculation to fit a slow 0.4 G/cm The cadmium spectrum suggests that the protons will resolve in the silicon, and the noise i h t i d i th f ll i i l

pp q y ( ), pwithin the 0 15 MHz variation band (pink lines)smaller “shim” coils to smooth out the field profile.

p pgradient is characterized in the following pixel map.within the 0.15 MHz variation band (pink lines). p gradient.

The spin flipping region of the magnet requires a Cadmium 109The spin-flipping region of the magnet requires a The inductance ring is tuned using a spectrum analyzer and the Q is measuredCadmium 109

radiofrequency birdcage resonator, which produces a field The inductance ring is tuned using a spectrum analyzer, and the Q is measured. q y g , pthat slowly rotates in the neutron’s reference frame tuned to: 32 Figure 8: z]

Frequency Tuning for Various Drive Resonator Frequency Response (dB) Figure 7: The that slowly rotates in the neutron s reference frame tuned to: 3132 g

FrequencyMH

z Modesg

resonator can beωrot = B·29.2 MHz/T. 31

D ||

Frequency response of they

[M resonator can be rung driven ( || )ωrot B 29.2 MHz/T.

N d Hi h U if it d Hi h Q30 Dec ||

Cou ||response of the

ncy rung-driven ( || )

Needs: High Uniformity and High Q. 29Cou ||

Dec Ser resonator from que or end-driven (ser),

28 Cou Ser a networkfreq ( ),

and measured by2 Efficient detection of decay products 27

28Desire: 28.5 MHz

a network anal eran

t f and measured by a pick p coil2. Efficient detection of decay products. 27 Set X: 8.7453 cm analyzer.

ona a pick-up coil

26Q f /Δf 330R

eso (dec) or by

6 8 10 Q = fc/Δf = 330 Ri Di l t [ ]

R

( ) yabsorption (cou) Figure 12: Noise characterizationRing Displacement [cm] absorption (cou). Figure 12: Noise characterization

N d d SiliN-doped SiliconConclusions and Future WorkConclusions and Future WorkConclusions and Future WorkConclusions and Future Work

P-doped Silicon

D b 2014 D R J F b 2015 D RP doped Silicon

d December 2014 Data Run: Jan-Feb 2015 Data Run:Needs:• Poor neutron flux • Imperfect but acceptable stability

Needs:• T bl h t t i i th h ld t t Poor neutron flux.

N t l kImperfect but acceptable stability.B t ti l d t t dFigure 3: Diagram of a silicon detector. The incoming radiation • Troubleshoot trigger, noise, thresholds to see protons.

• Neutron leakage. • Beta particles detected.Figure 3: Diagram of a silicon detector. The incoming radiation disturbs the depletion region of the reverse biased silicon • Regang the channels for a physics run

• Poor vacuum. • Protons mysteriously absent.disturbs the depletion region of the reverse-biased silicon, i ll f l d h l

Regang the channels for a physics run.B tt hi ldi d DAQ filt i t ill ti Poor vacuum. Protons mysteriously absent.creating a small current of electrons and holes. • Better shielding and DAQ filtering to escape oscillations.

El fl i i b h d f 10g Q g p

Electrons reflect; timing must be on the order of 10 ns. AcknowledgmentsAcknowledgments; gProtons have very little velocity; they will be accelerated to AcknowledgmentsAcknowledgmentsProtons have very little velocity; they will be accelerated to

J Bacon A Brandt L J Broussard C Cude E B Dees A T Holley T Ito M Makela P McGaughey J MirabalFi 13 Th i l ill b l d t di t ib t ili it30 keV. The SNR must be maximized to see them. J. Bacon, A. Brandt, L. J. Broussard, C. Cude, E.B. Dees, A.T. Holley,  T. Ito, M. Makela, P. McGaughey, J. Mirabal, C Morris R Neise R W Pattie J Ramsey D J Salvat S Sjue A Sprow T Womack B Zeck

Figure 13: The pixels will be evenly ganged to distribute silicon capacitance. C. Morris, R. Neise, R. W. Pattie, J. Ramsey, D.J. Salvat, S. Sjue,  A. Sprow, T. Womack, B. Zeck