Commit 843be1e4 authored by Zolnierczuk, Piotr's avatar Zolnierczuk, Piotr
Browse files

new flipper work 

new flipper field in biot-savart that should bring
the flipper curves closer to "reality"
parent a730983e

pysen/echo/flippers.py

+1 −3
Original line number Diff line number Diff line
@@ -20,6 +20,7 @@ def rxx13(omega_z, omega_x): 


def current_sheet(turns_density):

    "magnetic field of an infinite current sheet per unit current"

    #FIXME: move to Biot-Savart module

    return MU_0/2*turns_density
@@ -123,9 +124,6 @@ def make_flipper(name, params=None): 
            params = json.load(file)

            name = params.pop('name', 'unknown')

            return __make_flipper(name, params=params)

    except json.JSONDecodeError:

        print(f"Error: Could not decode JSON from the file '{name}'. Check the file format.")

        return None

    except FileNotFoundError:

        pass

pysen/physics/biotsavart.py

+45 −3
Original line number Diff line number Diff line
@@ -225,6 +225,7 @@ def bsheet_kernel(r, width, height): 
            by = by + k*log((rr-zz)/(rr+zz))/2

    return bx/_four_pi, by/_four_pi



#bsheet_kernel_vec = np.vectorize(bsheet_kernel, excluded={1, 'width', 2, 'height'})



def current_sheet_finite(r, s1, s2, s3):

    """
@@ -255,8 +256,8 @@ def current_sheet_finite(r, s1, s2, s3): 
    M  = np.vstack((ex,ey,ez))



    r  = r - (s2+s3)/2

    r = np.dot(M,r)



    r  = np.dot(M,r) # FIXME: works only for r(vectors) and not r[...,3] tensors

    #

    bx, by = bsheet_kernel(r,bb,hh)



    # Transformation of the field back into the original coordinate system
@@ -276,6 +277,8 @@ def current_sheet(r, s1, s2, s3, finite=True): 
        return current_sheet_finite(r, s1, s2, s3)

    return current_sheet_infinite(r)







# ============================================================================

# Helmholtz pairs and solenoids

# ============================================================================
@@ -314,6 +317,45 @@ def solenoid(r, radius=1, start=-0.5, end=+0.5, nturns=10): 
        bfield = bfield + db

    return bfield





# ============================================================================

# Flipper field

# ============================================================================

def flipper_field(r, thickness, width, length):

    """

    r         - obs. point

    thickness - along the beam (x-horizontal)

    width     - perp to beam   (y-horizontal)

    length    - vertical       (z-vertical)

    """

    b = np.zeros_like(r)



    # upstream plane

    xs1 = asarray(( -thickness/2, +width/2, -length/2))

    xs2 = asarray(( -thickness/2, -width/2, -length/2))

    xs3 = asarray(( -thickness/2, +width/2, +length/2))

    b  += current_sheet(r, xs1, xs2, xs3)



    # downstream plane

    xs1 = asarray(( +thickness/2, -width/2, +length/2))

    xs2 = asarray(( +thickness/2, +width/2, +length/2))

    xs3 = asarray(( +thickness/2, -width/2, -length/2))

    b  += current_sheet(r, xs1, xs2, xs3)



    # left (looking downstream)

    xs1 = asarray(( +thickness/2, +width/2, -length/2))

    xs2 = asarray(( -thickness/2, +width/2, -length/2))

    xs3 = asarray(( +thickness/2, +width/2, +length/2))

    b  += current_sheet(r, xs1, xs2, xs3)



    # right (looking downstream)

    xs1 = asarray(( -thickness/2, -width/2, +length/2))

    xs2 = asarray(( +thickness/2, -width/2, +length/2))

    xs3 = asarray(( -thickness/2, -width/2, -length/2))

    b  += current_sheet(r, xs1, xs2, xs3)



    return b



# ============================================================================

# Obsolete/Testing

# ============================================================================

pysen/plot/fliplotlib.py

+13 −6
Original line number Diff line number Diff line
@@ -11,7 +11,8 @@ from ..echo.flippers import make_flipper, tof_curve 


def plot_flipper_curve(axs, name='fpi', **kwargs):

    "test with plots"

    print(f"{name=}, {kwargs=}")

    log = logging.getLogger()

    log.debug("plot_flipper_curve(%s, %s)", name, kwargs)

    pos     = kwargs.pop('pos', 'p2')

    freq    = kwargs.pop('freq', 60.0)

    points  = kwargs.pop('points', 163)
@@ -24,7 +25,9 @@ def plot_flipper_curve(axs, name='fpi', **kwargs): 
    b_z     = kwargs.pop('bfield_z', 0.0) # vertical   external field in Tesla

    fname   = kwargs.pop('file', None)    # flipper definition file



    log = logging.getLogger()

    log.debug("pos=%s freq=%g points=%d shift=%g lmax=%g compare=%s scale=%g b_x=%g b_z=%g fname=%s",

              pos, freq, points, shift, lmax, compare, scale, b_x, b_z, fname)



    L  =  Ltot.get(pos) # [m] source to detector

    L1 =  L - L2 # [m] source to sample

    B_ext = np.asarray([ b_x, 0.0, b_z])  # ext. field
@@ -36,10 +39,14 @@ def plot_flipper_curve(axs, name='fpi', **kwargs): 
        except FileNotFoundError as err:

            log.error("cannot load compare file (%s)",err)

            compare_data = None

    try:

        if fname:

            flipper = make_flipper(fname)

        else:

            flipper = make_flipper(name)

    except ValueError as err:

        log.error("cannot create flipper (%s)", err)

        return None, None

    title = rf'{flipper.name} $\lambda_{{max}}$={lmax:g}$\AA$'



    delam = HMN/(freq*L) # wavelengtgh band

pysen/revision.py

+2 −2
Original line number Diff line number Diff line
@@ -2,8 +2,8 @@ 
PySEN revision module

"""

import sys

__version__  = "2.1.0.dev9"

__date__     = "Mar 12, 2026"

__version__  = "2.1.0.dev10"

__date__     = "Mar 19, 2026"



def version(full=False):

    "get pysen version number"

test/data/flipper_err.json

0 → 100644
+7 −0
Original line number Diff line number Diff line 
{

    "name": "new_flipper",

    "type": "pi"

    "position": -1.2345678,

    "thickness": 0.314,

    "turns_density": 333.33

}