Exemple #1
0
def measBeta(elem, dqk1=0.01, full=False, num_points=3, verbose=0):
    """
    Measure the beta function by varying quadrupole strength

    Parameters
    -----------
    elem : element name, name list or pattern.
    dqk1 : float. the quadrupole change range [-dqk1, dqk1]
    full : bool. returns more data besides beta
    num_points : int. points in [-dqk1, dqk1] to fit the line, default 3.
    verbose : verbose

    Returns
    --------
    beta : numpy array (N_elements, 3). fitted betax, betay and s_center
    k1, nu : optional. present only if *full*=True.
        k1 is numpy array (N_elements, num_points), quadrupole settings. nu is
        numpy array (N_elements, num_points, 2). tunes.

    Notes
    ------
    see `getElements` for acceptable *elem* format. Some users prefer using
    turn-by-turn BPM data to calculate the beta functions
    """

    elems = getElements(elem)
    if elems is None:
        raise ValueError("can not find element '%s'" % elem)
    if verbose:
        print("# fitting %d quadrupoles:" % len(elems))
        print("# " + ' '.join([q.name for q in elems]))

    kwargs = {'dqk1': dqk1, 'num_points': num_points, 'verbose': verbose}

    nux, nuy = getTunes()
    nu = np.zeros((len(elems), num_points, 2), 'd')
    k1 = np.zeros((len(elems), num_points), 'd')
    beta = np.zeros((len(elems), 3), 'd')
    for i, q in enumerate(elems):
        beta[i, -1] = (q.sb + q.se) / 2.0
        # is an element
        k1[i, :], nu[i, :, :] = _measBetaQuad(q, **kwargs)
        if verbose:
            print(i, q.name, q.k1, end=" ")
        p, res, rank, sv, rcond = np.polyfit(k1[i, :],
                                             nu[i, :, :],
                                             deg=1,
                                             full=True)
        # p[0,k] is the highest power for dataset k
        beta[i, :2] = p[0, :] * 4 * np.pi / q.length
        # reverse the k1 for vertical direction
        beta[i, 1] = -beta[i, 1]
        print(q.sb, q.name, beta[i, 0], beta[i, 1], p[0, :])

    if full: return beta, k1, nu
    else: return beta
Exemple #2
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def measBeta(elem, dqk1=0.01, full=False, num_points=3, verbose=0):
    """
    Measure the beta function by varying quadrupole strength

    Parameters
    -----------
    elem : element name, name list or pattern.
    dqk1 : float. the quadrupole change range [-dqk1, dqk1]
    full : bool. returns more data besides beta
    num_points : int. points in [-dqk1, dqk1] to fit the line, default 3.
    verbose : verbose

    Returns
    --------
    beta : numpy array (N_elements, 3). fitted betax, betay and s_center
    k1, nu : optional. present only if *full*=True.
        k1 is numpy array (N_elements, num_points), quadrupole settings. nu is
        numpy array (N_elements, num_points, 2). tunes.

    Notes
    ------
    see `getElements` for acceptable *elem* format. Some users prefer using
    turn-by-turn BPM data to calculate the beta functions
    """

    elems = getElements(elem)
    if elems is None:
        raise ValueError("can not find element '%s'" % elem)
    if verbose:
        print("# fitting %d quadrupoles:" % len(elems))
        print("# " + " ".join([q.name for q in elems]))

    kwargs = {"dqk1": dqk1, "num_points": num_points, "verbose": verbose}

    nux, nuy = getTunes()
    nu = np.zeros((len(elems), num_points, 2), "d")
    k1 = np.zeros((len(elems), num_points), "d")
    beta = np.zeros((len(elems), 3), "d")
    for i, q in enumerate(elems):
        beta[i, -1] = (q.sb + q.se) / 2.0
        # is an element
        k1[i, :], nu[i, :, :] = _measBetaQuad(q, **kwargs)
        if verbose:
            print(i, q.name, q.k1, end=" ")
        p, res, rank, sv, rcond = np.polyfit(k1[i, :], nu[i, :, :], deg=1, full=True)
        # p[0,k] is the highest power for dataset k
        beta[i, :2] = p[0, :] * 4 * np.pi / q.length
        # reverse the k1 for vertical direction
        beta[i, 1] = -beta[i, 1]
        print(q.sb, q.name, beta[i, 0], beta[i, 1], p[0, :])

    if full:
        return beta, k1, nu
    else:
        return beta
Exemple #3
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def _measBetaQuad(elem, **kwargs):
    dqk1 = abs(kwargs.get("dqk1", 0.01))
    num_points = kwargs.get("num_points", 5)
    minwait = kwargs.get("minwait", 3)

    qk10 = elem.k1
    qk1 = qk10 + np.linspace(-dqk1, dqk1, num_points)
    nu = np.zeros((num_points, 2), "d")
    for i, k1 in enumerate(qk1):
        v0 = getOrbit()
        elem.k1 = k1
        waitStableOrbit(v0, minwait=minwait, maxwait=15)
        nu[i, :] = getTunes()

    elem.k1 = qk10
    return qk1, nu
Exemple #4
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def _measBetaQuad(elem, **kwargs):
    dqk1 = abs(kwargs.get('dqk1', 0.01))
    num_points = kwargs.get('num_points', 5)
    minwait = kwargs.get('minwait', 3)

    qk10 = elem.k1
    qk1 = qk10 + np.linspace(-dqk1, dqk1, num_points)
    nu = np.zeros((num_points, 2), 'd')
    for i, k1 in enumerate(qk1):
        v0 = getOrbit()
        elem.k1 = k1
        waitStableOrbit(v0, minwait=minwait, maxwait=15)
        nu[i, :] = getTunes()

    elem.k1 = qk10
    return qk1, nu
Exemple #5
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def _measChromaticity(**kwargs):
    """Measure the chromaticity

    Parameters
    -----------
    dfmax - max RF frequency change (within plus/minus), 1e-6
    gamma - beam, 3.0/0.511e-3
    alphac - momentum compaction factor, 3.62619e-4
    wait - 1.5 second
    num_points - 5

    returns dp/p, nu, chrom
    dpp - dp/p energy deviation
    nu - tunes 
    chrom - result chromaticities 
    obt - orbit at each f settings (initial, every df, final).
    """
    dfmax = kwargs.get("dfmax", 1e-6)
    gamma = kwargs.get("gamma", 3.0e3 / 0.511)
    alphac = kwargs.get("alphac", 3.6261976841792413e-04)
    wait = kwargs.get("wait", 1.5)
    npt = kwargs.get("num_points", 5)
    verbose = kwargs.get("verbose", 0)

    eta = alphac - 1 / gamma / gamma

    obt = []
    f0 = getRfFrequency(handle="setpoint")
    nu0 = getTunes()
    obt.append(getOrbit(spos=True))
    _logger.info("Initial RF freq= {0}, tunes= {1}" % (f0, nu0))

    # incase RF does not allow large step change, ramp down first
    if verbose:
        print("Initial RF freq= {0}, stepping down {1} in {2} steps".format(f0, -dfmax, npt))
    for df in np.linspace(0, abs(dfmax), npt)[1:-1]:
        putRfFrequency(f0 - df)
        time.sleep(2.0 / npt)

    f = np.linspace(f0 - dfmax, f0 + dfmax, npt)
    nu = np.zeros((len(f), 2), "d")
    for i, f1 in enumerate(f):
        if verbose > 0:
            print("freq= ", f1, end=" ")
        putRfFrequency(f1)
        time.sleep(wait)
        nu[i, :] = getTunes()
        obt.append(getOrbit(spos=True))
        if verbose > 0:
            print(
                "tunes:",
                nu[i, 0],
                nu[i, 1],
                np.min(obt[-1][:, 0]),
                np.max(obt[-1][:, 0]),
                np.min(obt[-1][:, 1]),
                np.max(obt[-1][:, 1]),
            )

    for df in np.linspace(0, abs(dfmax), npt):
        putRfFrequency(f0 + abs(dfmax) - df)
        time.sleep(2.0 / npt)

    obt.append(getOrbit(spos=True))

    df = f - f0
    dnu = nu - np.array(nu0)
    p, resi, rank, sing, rcond = np.polyfit(df, dnu, deg=2, full=True)
    chrom = p[-2, :] * (-f0 * eta)
    if verbose > 0:
        print("Coef:", p)
        print("Resi:", resi)
        print("Chrom:", chrom)
    return df / (-f0 * eta), nu, chrom, obt
Exemple #6
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def measChromaticity(
    dfmax=1e-6, gamma=3.0e3 / 0.511, alphac=3.626e-4, num_points=5, fMeasTunes=None, deg=2, wait=0.5, verbose=0
):
    """Measure the chromaticity

    Parameters
    -----------
    dfmax - max RF frequency change (within plus/minus), 1e-6
    gamma - beam, 3.0/0.511e-3
    alphac - momentum compaction factor, 3.62619e-4
    wait - 1.5 second
    num_points - 5
    fMeasTunes - function used to get tunes. default None, use getTunes().

    returns
    --------
    chrom : chromaticity, (chx, chy)
    info : dictionary
        freq : list of frequency setting
        freq0 : initial frequency setpoint
        tune : list of tunes,  shape (num_points, 2)
        dpp : dp/p energy deviation
        obt : orbit at each f settings (initial, every df, final).
        deg : degree of polynomial fitting.
        p : polynomial coeff, shape (deg+1, 2)
    """
    obt = []
    f0 = getRfFrequency(handle="setpoint")

    # names, x0, y0, Isum0, timestamp, offset = \
    #    measKickedTbtData(7, (0.15, 0.2), sleep=10, output=False)
    # nu0 = (calcFftTunes(x0), calcFftTunes(y0))
    nu0 = fMeasTunes() if fMeasTunes else getTunes()

    obt.append(getOrbit(spos=True))
    # _logger.info("Initial RF freq= {0}, tunes= {1}" % (f0, nu0))

    # incase RF does not allow large step change, ramp down first
    if verbose:
        print("Initial RF freq= {0}, stepping down {1} in {2} steps".format(f0, -dfmax, num_points))
    for df in np.linspace(0, abs(dfmax), num_points)[1:-1]:
        putRfFrequency(f0 - df)
        time.sleep(2.0 / num_points)

    f = np.linspace(f0 - dfmax, f0 + dfmax, num_points)
    nu = np.zeros((len(f), 2), "d")
    for i, f1 in enumerate(f):
        if verbose > 0:
            print("dfreq= {0: .2e}".format(f1 - f0), end=" ")
        putRfFrequency(f1)
        time.sleep(wait)
        nu[i, :] = fMeasTunes() if fMeasTunes else getTunes()
        obt.append(getOrbit(spos=True))
        if verbose > 0:
            print(
                "tunes: {0:.5f} {1:.5f}".format(nu[i, 0], nu[i, 1]),
                "orbit min-max: {0:.2e} {1:.2e}, {2:.2e} {3:.2e}".format(
                    np.min(obt[-1][:, 0]), np.max(obt[-1][:, 0]), np.min(obt[-1][:, 1]), np.max(obt[-1][:, 1])
                ),
            )

    for df in np.linspace(0, abs(dfmax), num_points):
        putRfFrequency(f0 + abs(dfmax) - df)
        time.sleep(2.0 / num_points)
    obt.append(getOrbit(spos=True))

    # calculate chrom, return info
    info = {"freq": f, "tune": nu, "orbit": obt, "freq0": f0, "deg": deg}
    chrom, dpp, p = calcChromaticity(f0, f, nu, deg=deg)
    info["dpp"] = dpp
    info["p"] = p

    return chrom, info
Exemple #7
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def _measChromaticity(**kwargs):
    """Measure the chromaticity

    Parameters
    -----------
    dfmax - max RF frequency change (within plus/minus), 1e-6
    gamma - beam, 3.0/0.511e-3
    alphac - momentum compaction factor, 3.62619e-4
    wait - 1.5 second
    num_points - 5

    returns dp/p, nu, chrom
    dpp - dp/p energy deviation
    nu - tunes 
    chrom - result chromaticities 
    obt - orbit at each f settings (initial, every df, final).
    """
    dfmax = kwargs.get("dfmax", 1e-6)
    gamma = kwargs.get("gamma", 3.0e3 / .511)
    alphac = kwargs.get("alphac", 3.6261976841792413e-04)
    wait = kwargs.get("wait", 1.5)
    npt = kwargs.get("num_points", 5)
    verbose = kwargs.get("verbose", 0)

    eta = alphac - 1 / gamma / gamma

    obt = []
    f0 = getRfFrequency(handle="setpoint")
    nu0 = getTunes()
    obt.append(getOrbit(spos=True))
    _logger.info("Initial RF freq= {0}, tunes= {1}" % (f0, nu0))

    # incase RF does not allow large step change, ramp down first
    if verbose:
        print("Initial RF freq= {0}, stepping down {1} in {2} steps".format(
            f0, -dfmax, npt))
    for df in np.linspace(0, abs(dfmax), npt)[1:-1]:
        putRfFrequency(f0 - df)
        time.sleep(2.0 / npt)

    f = np.linspace(f0 - dfmax, f0 + dfmax, npt)
    nu = np.zeros((len(f), 2), 'd')
    for i, f1 in enumerate(f):
        if verbose > 0:
            print("freq= ", f1, end=" ")
        putRfFrequency(f1)
        time.sleep(wait)
        nu[i, :] = getTunes()
        obt.append(getOrbit(spos=True))
        if verbose > 0:
            print("tunes:", nu[i, 0], nu[i, 1], np.min(obt[-1][:, 0]),
                  np.max(obt[-1][:, 0]), np.min(obt[-1][:, 1]),
                  np.max(obt[-1][:, 1]))

    for df in np.linspace(0, abs(dfmax), npt):
        putRfFrequency(f0 + abs(dfmax) - df)
        time.sleep(2.0 / npt)

    obt.append(getOrbit(spos=True))

    df = f - f0
    dnu = nu - np.array(nu0)
    p, resi, rank, sing, rcond = np.polyfit(df, dnu, deg=2, full=True)
    chrom = p[-2, :] * (-f0 * eta)
    if verbose > 0:
        print("Coef:", p)
        print("Resi:", resi)
        print("Chrom:", chrom)
    return df / (-f0 * eta), nu, chrom, obt
Exemple #8
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def measChromaticity(dfmax=1e-6,
                     gamma=3.0e3 / 0.511,
                     alphac=3.626e-4,
                     num_points=5,
                     fMeasTunes=None,
                     deg=2,
                     wait=0.5,
                     verbose=0):
    """Measure the chromaticity

    Parameters
    -----------
    dfmax - max RF frequency change (within plus/minus), 1e-6
    gamma - beam, 3.0/0.511e-3
    alphac - momentum compaction factor, 3.62619e-4
    wait - 1.5 second
    num_points - 5
    fMeasTunes - function used to get tunes. default None, use getTunes().

    returns
    --------
    chrom : chromaticity, (chx, chy)
    info : dictionary
        freq : list of frequency setting
        freq0 : initial frequency setpoint
        tune : list of tunes,  shape (num_points, 2)
        dpp : dp/p energy deviation
        obt : orbit at each f settings (initial, every df, final).
        deg : degree of polynomial fitting.
        p : polynomial coeff, shape (deg+1, 2)
    """
    obt = []
    f0 = getRfFrequency(handle="setpoint")

    #names, x0, y0, Isum0, timestamp, offset = \
    #    measKickedTbtData(7, (0.15, 0.2), sleep=10, output=False)
    #nu0 = (calcFftTunes(x0), calcFftTunes(y0))
    nu0 = fMeasTunes() if fMeasTunes else getTunes()

    obt.append(getOrbit(spos=True))
    #_logger.info("Initial RF freq= {0}, tunes= {1}" % (f0, nu0))

    # incase RF does not allow large step change, ramp down first
    if verbose:
        print("Initial RF freq= {0}, stepping down {1} in {2} steps".format(
            f0, -dfmax, num_points))
    for df in np.linspace(0, abs(dfmax), num_points)[1:-1]:
        putRfFrequency(f0 - df)
        time.sleep(2.0 / num_points)

    f = np.linspace(f0 - dfmax, f0 + dfmax, num_points)
    nu = np.zeros((len(f), 2), 'd')
    for i, f1 in enumerate(f):
        if verbose > 0:
            print("dfreq= {0: .2e}".format(f1 - f0), end=" ")
        putRfFrequency(f1)
        time.sleep(wait)
        nu[i, :] = fMeasTunes() if fMeasTunes else getTunes()
        obt.append(getOrbit(spos=True))
        if verbose > 0:
            print(
                "tunes: {0:.5f} {1:.5f}".format(nu[i, 0], nu[i, 1]),
                "orbit min-max: {0:.2e} {1:.2e}, {2:.2e} {3:.2e}".format(
                    np.min(obt[-1][:, 0]), np.max(obt[-1][:, 0]),
                    np.min(obt[-1][:, 1]), np.max(obt[-1][:, 1])))

    for df in np.linspace(0, abs(dfmax), num_points):
        putRfFrequency(f0 + abs(dfmax) - df)
        time.sleep(2.0 / num_points)
    obt.append(getOrbit(spos=True))

    # calculate chrom, return info
    info = {"freq": f, "tune": nu, "orbit": obt, "freq0": f0, "deg": deg}
    chrom, dpp, p = calcChromaticity(f0, f, nu, deg=deg)
    info["dpp"] = dpp
    info["p"] = p

    return chrom, info