Parameter Report for North Telescope LSTN-01 (Version 5.0.0)#

LSTN-01#

Parameter Name

Values

Short Description

pixeltrg_time_step

0.0 ns

Time difference between telescope and pixel trigger recording.

focus_offset

[<Quantity 6.55 cm>, <Quantity 0. deg>, <Quantity 0.>, <Quantity 0.>]

Distance of the starlight focus from the camera pixels (light guides)

entry.

discriminator_scale_threshold

1.0

Discriminator/comparator threshold scale factor.

qe_variation

0.03

None

nsb_pixel_rate

[0.238006 0.238006 0.238006 … 0.238006 0.238006 0.238006] GHz

Number of photo-electrons per nanosecond per pixel due to nightsky

background.

photon_delay

19.0 ns

None

discriminator_var_sigsum_over_threshold

0.0 mV ns

None

discriminator_threshold

99999.0 mV

None

focal_length

2800.0 cm

Nominal overall focal length of the entire telescope.

fadc_bins

75

Number of FADC bins to be simulated.

fadc_lg_pedestal

400.0 ct

None

mirror_class

0

Parameter to control the type of mirror used (DC, parabolic or SC).

asum_clipping

9999.0 mV

None

mirror_list

mirror_CTA-N-LST1_v2019-03-31.dat

None

fadc_lg_err_pedestal

0.3 ct

Assumed error in initial calibration of pedestal

(low-gain channels; affects only the reported pedestal).

fadc_lg_noise

5.7 ct

Gaussian r.m.s. spread of white noise per time bin in digitisation (low-gain channels).

camera_transmission

1.0

Global wavelength-independent transmission factor of the camera,

including any plexiglass window.

fadc_max_sum

16777215.0 ct

The maximum value of a pulse sum produced by hardware pulse summation,

in sum mode rather than recording pulse samples.

flatfielding

True

None

fadc_sum_offset

9

Number of bins before telescope trigger where summing or reading of

sampled data starts.

nsb_offaxis

[<Quantity 0.>, <Quantity 0.>, <Quantity 0. cm>, <Quantity 0.>, <Quantity 0.>]

Fall-off of NSB with off-axis angle due to off-axis angle-dependent

effective optical area.

camera_body_shape

2

Camera body shape parameter (used to account for effects of shadowing).

discriminator_output_amplitude

42.0 mV

The nominal output amplitude of a pixel discriminator as seen at the

trigger group coincidence unit.

fadc_amplitude

25.0 ct

Peak amplitude above pedestal for a photo electron with average signal.

discriminator_pulse_shape

pulse_LST_8dynode_pix6_20200204.dat

None

nsb_autoscale_airmass

[<Quantity 0.84>, <Quantity 0.29>]

NSB scaling as function of airmass (zenith angle).

optics_properties

ray-tracing-North-LST-1-d10.0-za20.0_validate_optics.ecsv

None

gain_variation

0.0187

Fractional gain variation between different photo detectors after

adjusting the voltage to have approximately the same gain in all channels.

discriminator_output_var_percent

10.0 %

Channel-to-channel variation (Gaussian r.m.s.) of the output amplitude

of a pixel discriminator.

mirror_reflectivity

ref_LST_2020-04-23.dat

None

hg_lg_variation

0.0

None

fadc_noise

6.7 ct

Gaussian r.m.s. spread of white noise per time bin in digitisation.

asum_threshold

270.0 mV

None

disc_bins

68

Number of time bins used for the discriminator simulation.

transit_time_calib_error

0.0 ns

None

fadc_var_pedestal

0.4 ct

None

telescope_transmission

[<Quantity 0.969>, <Quantity 0.>, <Quantity 0.>, <Quantity 0.>, <Quantity 0.>, <Quantity 0.>]

Off-axis angle-dependent transmission, accounting for absorption and

shadowing by masts.

discriminator_fall_time

1.0 ns

Fall time of the discriminator output after the logical output is

reset to false.

fadc_pulse_shape

pulse_LST_8dynode_pix6_20200204.dat

(F)ADC pulse shape (amplitude vs time).

fadc_pedestal

400.0 ct

None

telescope_random_angle

0.0 deg

None

telescope_sphere_radius

12.5 m

Telescope fiducial sphere radius.

fadc_max_signal

4249.0 ct

Maximum value of digitized signal per sample.

discriminator_var_threshold

0.2 mV

Channel-to-channel variation of discriminator threshold.

effective_focal_length

[2930.57 0. 0. 0. 0. ] cm

Effective focal length.

Only to be used for image analysis, has no effect on the simulation.

camera_degraded_map

None

Position-dependent map of degradation factors for the camera efficiency.

pm_transit_time

[<Quantity 24.74 ns>, <Quantity 9. ns>, <Quantity 350. V>, <Quantity 1066. V>]

None

trigger_pixels

3

Number of pixels required for single telescope trigger.

camera_config_file

camera_CTA-LST-1_analogsum21_v2020-04-14.dat

None

disc_start

3

Number of time bins by which the discriminator simulation is ahead of

the FADC readout.

pm_average_gain

40000.0

None

fadc_sum_bins

40

Number of bins read out in sampled data or summed up in ADC sum data.

Corresponds to the experimental length of the readout window.

mirror_focal_length

0.0 cm

Standard focal length of mirror tiles.

discriminator_var_time_over_threshold

0.1 ns

None

array_element_position_utm

[2.17659590e+05 3.18499506e+06 2.18500000e+03] m

UTM coordinate position of an array element.

teltrig_min_sigsum

7.8 mV ns

Minimum signal sum at sector trigger over threshold.

mirror_reflection_random_angle

[<Quantity 0.0075 deg>, <Quantity 0.125>, <Quantity 0.037 deg>]

Gaussian r.m.s. spread of random fluctuations of microscopic reflection

angles due to small-scale surface deviations.

fadc_sysvar_pedestal

0.04 ct

Systematic common variations of pedestals.

camera_degraded_efficiency

1.0

Camera efficiency degradation factor (wavelength independent).

array_element_position_ground

[-70.93 -52.07 43. ] m

Ground coordinate position of an array element.

fadc_err_pedestal

0.5 ct

Assumed error in initial calibration of pedestal

(affects only the reported pedestal).

asum_offset

0.0 ns

None

transit_time_compensate_step

0.0 ns

None

discriminator_sigsum_over_threshold

0.0 mV ns

Integrated signal required over threshold.

mirror_align_random_horizontal

[<Quantity 0.0039 deg>, <Quantity 28. deg>, <Quantity 0.>, <Quantity 0.>]

Gaussian r.m.s. spread of random fluctuations of the mirror alignment

angle with respect to nominal alignment in the horizontal component.

axes_offsets

[<Quantity 0. cm>, <Quantity 0. cm>]

Geometric offsets to be used in case that the azimuth, altitude,

and optical axes do not intersect at the reference point.

mirror_degraded_reflection

1.0

Mirror degradation factor (wavelength independent).

mirror_align_random_vertical

[<Quantity 0.0039 deg>, <Quantity 28. deg>, <Quantity 0.>, <Quantity 0.>]

Gaussian r.m.s. spread of random fluctuations of the mirror alignment

angle with respect to nominal alignment in the vertical component.

teltrig_min_time

0.5 ns

None

fadc_lg_compensate_pedestal

-1

Emulation of FADC pedestal compensation.

fadc_compensate_pedestal

-1

Emulation of FADC pedestal compensation.

default_trigger

AnalogSum

None

fadc_lg_max_signal

4288.0 ct

Maximum value of digitized signal per sample (low-gain channels).

quantum_efficiency

qe_lst1_20200318_high+low.dat

None

mirror_align_random_distance

0.0 cm

None

discriminator_gate_length

2.0 ns

Effective discriminator gate length.

fadc_var_sensitivity

0.01416

None

fadc_lg_err_compensate_pedestal

-1.0

R.M.S. error on the pedestal evaluation for the compensation step.

channels_per_chip

4

Number of channels per readout chip.

fadc_err_compensate_pedestal

0.0

R.M.S. error on the pedestal evaluation for the compensation step.

transit_time_compensate_error

0.0 ns

None

mirror_offset

93.25 cm

Offset of mirror back plane from fixed point of telescope mount or

from the altitude rotation axis, along the direction of the optical axis.

discriminator_rise_time

1.0 ns

Rise time of the discriminator output. The output signal rises linearly

within time frame.

fadc_ac_coupled

True

AC coupling of the FADCs.

camera_depth

0.0 cm

Depth of the camera body (used to account for effects of shadowing).

discriminator_time_over_threshold

1.5 ns

Time over threshold required before logic response switches to true.

dish_shape_length

2800.0 cm

Dish curvature length, best equal to focal length.

random_focal_length

[<Quantity 0. cm>, <Quantity 0. cm>]

The spread of random fluctuations in mirror focal lengths.

fadc_mhz

1024.0 MHz

None

trigger_current_limit

20.0 uA

None

fadc_lg_var_sensitivity

-1.0

None

fadc_lg_sysvar_pedestal

-1.0 ct

Systematic common variations of pedestals (low-gain channels).

parabolic_dish

True

Parabolic dish shape is used.

pm_voltage_variation

0.041

Fractional high voltage variation, used to adjust the transit time

variations (\(\propto 1/\sqrt(V)\)).

telescope_axis_height

16.0 m

None

fadc_lg_amplitude

1.28 ct

Peak amplitude above pedestal for a photo electron with average signal (low-gain channels).

discriminator_var_gate_length

0.1 ns

Variation of gate length (Gaussian r.m.s).

transit_time_jitter

0.7 ns

None

asum_shaping

None

None

discriminator_hysteresis

0.0 mV

Value of the discriminator hysteresis.

fadc_sensitivity

1.0 ct / mV

FADC counts per mV voltage.

telescope_random_error

0.0 deg

None

camera_filter

transmission_lst_window_No7-10_ave.dat

Wavelength dependence of the camera transmission, possibly as a function

of incidence angle.

discriminator_amplitude

6.5 mV

None

trigger_delay_compensation

[<Quantity 0. ns>, <Quantity 0. ns>, <Quantity 0. ns>, <Quantity 0. ns>]

The delay applied to the trigger output to compensate for the different

execution times of each trigger algorithm.

disc_ac_coupled

True

Control AC coupling of the discriminators.

transit_time_error

0.0 ns

Errors (r.m.s.) in transit time, not related to high voltage.

camera_pixels

1855

None

multiplicity_offset

-0.5

Actual threshold of the telescope trigger, adjusted relative to the

number of required pixels.

pm_gain_index

4.5

None

only_triggered_telescopes

True

Switch to read out non-triggered telescopes.

pm_collection_efficiency

1.0

Photoelectron collection efficiency at the first stage of the photo

detector.

pm_photoelectron_spectrum

spe_LST_2020-05-09_AP2.0e-4.dat

None

fadc_lg_var_pedestal

0.4 ct

None

fadc_lg_sensitivity

-1.0 ct / mV

FADC counts per mV voltage (for low-gain channels).

num_gains

2

None

lightguide_efficiency_vs_incidence_angle

CTA-LST_lightguide_eff_2020-04-12_average.dat

Lightguide efficiency as a function of incidence angle.

camera_body_diameter

348.0 cm

None