Institute for Theoretical and Experimental Physics, Moscow, 117218, Russia.
N.A. Bazhanov, E.I. Bunyatova
Joint Institute for Nuclear Research, Dubna, Moscow district, 141980, Russia.
D. Novinsky (PNPI)
The polarization parameters (P, R, A) measurement results above pion momentum above 1000 MeV/c made it possible to resolve part of discrete ambiguities in existing partial-wave analyses (PWA’s)The polarization experiments at N-elastic scattering use the proton polarized target.The experiment uses a polarized proton target in which free protons have vertical polarization or polarization in the elastic scattering plane.Uncertainty (abs.) is ±~2% at 70% of polarization magnitude.The area under the PMR curve is determined using a Q meter.
Preface
D. Novinsky (PNPI)
The physics goals
D. Novinsky (PNPI)
Experimental Setup, ITEP (Moscow)
D. Novinsky (PNPI)
MAIN ELEMENTS: Vertically polarized proton target PT 4 sets of wire chambers for tracking Trigger scintillation counters
TARGET: Cylinder 30mm, h=30mm, propanediole C3H8O2, free proton density 10 % Magnetic field 2.5 T 3He evaporation type cryostat at 0.5 K Dynamic nuclear orientation Polarization (70-80) %, measurement accuracy ±2 % Sign reverse once per day
1 – target window, 2 – nitrogen screen,3 – magnet area, 4 – container with the target (C3H8O2) matter inside
superconductive Helmholz coils
Polarization measurements
D. Novinsky (PNPI)
polarization pump by the dynamic nuclear orientation method up to absolute value 70–80% method of proton magnetic resonance (PMR),measurements are based on the calculations of square under the PMR curve: the system containing Q-meter with sequential contour and signal digitalizationCalibration is based on the equilibrium state at temperature 0.8 – 1.4 K
Polarization measurements
D. Novinsky (PNPI)
Signal and backgroundBackground: to take away signal from center by means of the magnetic field change
Polarization measurements
D. Novinsky (PNPI)
Calibration: the equilibrium state
Electronic providing of the polarized target
Modernization of the target measurements Two PCI-cards are inserted into the PC-board (Remote computer PC1 ). Usage of PCI-card DAS6036 and the PCI-card PCI-1723ADC and DAC with grade ≥ 14 bit, transformation is run by timer FIFO Transformation time ≤ 8 s Usage of the new current source “Lambda-Genesys” for power supply
of superconductive coils
D. Novinsky (PNPI)
Current situation
D. Novinsky (PNPI)
PCI-cards and programs are tested at PNPI Current source is tested at PNPI and ITEP (Moscow)Target location: ITEP
To continue spin rotation parameters
mearurements, e.g. J-PARC
at PNPI accelerator
Cryostat at PNPI Netron Physics Department
More than 20 years experiments
Conclusions
Acknowledgements
GREAT THANKS to the Organizing Committee ! ! !
D. Novinsky (PNPI)
Successful target work > 20 years Modernization and new tests are requiredNew physics tasks
In memory of A.I. Kovalev (1936-2011)
PCI-card PCI-DAS6036
Low-cost, 16-channel, 200 kS/s analog I/O boards with two 16-bit analog outputs, eight digital I/O, and two counter/timers
16 channels of 16-bit A/D resolution200 kS/s maximum sample rate2 channels of 16-bit D/A at 10 kHz8 bits DIO 2 16-bit counters
D. Novinsky (PNPI)
PCI-card PCI-1723 (Advantech)
16-bit, 8-channel Non-isolated Analog Output CardMain Features Auto calibration function A 16-bit DAC is equipped for each analog output channel Synchronized output function Output values retained after system hot reset 2-port (16-channel) user-defined digital input/output Board ID
