Merge branch 'b-laser-materials' into 'v2.4-stable' (d6ce5aab) · Commits · XRFLab109 / Allpix Squared

src/modules/DepositionLaser/DepositionLaserModule.cpp

+52 −37

Original line number	Diff line number	Diff line
		@@ -96,21 +96,16 @@ DepositionLaserModule::DepositionLaserModule(Configuration& config, Messenger* m
		}

		void DepositionLaserModule::initialize() {

		// Check for incompatible passive objects, warn user if there are any
		auto passive_configs = geo_manager_->getPassiveElements();
		for(const auto& item : passive_configs) {
		auto shape = item.get<std::string>("type");
		if(shape != "box") {
		LOG(WARNING) << item.getName() << " passive object has unsupported type (" << shape << ") and will be ignored";
		}
		}

		// Check if there are user-specified optical properties for materials
		is_user_optics_ = (config_.count({"absorption_length", "refractive_index"}) == 2);
		if(is_user_optics_) {
		absorption_length_ = config_.get<double>("absorption_length");
		refractive_index_ = config_.get<double>("refractive_index");
		LOG(DEBUG) << "Setting user-defined optical properties for sensor material";
		} else {
		// Load data
		std::string laser_data_path = ALLPIX_LASER_DATA_DIRECTORY;

		std::ifstream f(std::filesystem::path(laser_data_path) / "silicon_photoabsorption.data");

		// wavelength: {absorption_length, refractive_index}
		std::map<double, std::pair<double, double>> optics_lut;
		double wl = 0;
		@@ -121,7 +116,7 @@ void DepositionLaserModule::initialize() {
		optics_lut[Units::get(wl, "nm")] = {abs_length, refr_ind};
		}

		LOG(DEBUG) << "Loading absorption data: " << laser_data_path;
		LOG(DEBUG) << "Loading optical properties for sensor material from LUT: " << laser_data_path;

		// Find or interpolate absorption depth for given wavelength

		@@ -137,11 +132,29 @@ void DepositionLaserModule::initialize() {
		refractive_index_ =
		(optics_lut[wl1].second * (wl2 - wavelength_) + optics_lut[wl2].second * (wavelength_ - wl1)) / (wl2 - wl1);
		}

		}
		LOG(DEBUG) << "Wavelength = " << Units::display(wavelength_, "nm")
		<< ", absorption length: " << Units::display(absorption_length_, {"um", "mm"})
		<< ", refractive index: " << refractive_index_;

		// Check for unsupported detector materials, warn user if present

		std::vector<std::shared_ptr<Detector>> detectors = geo_manager_->getDetectors();
		for(auto& detector : detectors) {
		auto material = detector->getModel()->getSensorMaterial();
		if(material != SensorMaterial::SILICON && !is_user_optics_) {
		LOG(WARNING) << "Detector " << detector->getName() << " has unsupported material and will be ignored";
		}
		}
		// Check for incompatible passive objects, warn user if there are any
		auto passive_configs = geo_manager_->getPassiveElements();
		for(const auto& item : passive_configs) {
		auto shape = item.get<std::string>("type");
		if(shape != "box") {
		LOG(WARNING) << item.getName() << " passive object has unsupported type (" << shape << ") and will be ignored";
		}
		}

		// Create Histograms
		if(output_plots_) {
		LOG(DEBUG) << "Initializing histograms";
		@@ -179,7 +192,6 @@ void DepositionLaserModule::initialize() {
		h_pulse_shape_ =
		CreateHistogram<TH1D>("pulse_shape", "Phi_distribution w.r.t. beam direction", nbins, 0, 8 * pulse_duration_);

		std::vector<std::shared_ptr<Detector>> detectors = geo_manager_->getDetectors();
		for(const auto& detector : detectors) {
		std::string name = "dep_charge_" + detector->getName();
		auto sensor = detector->getModel()->getSensorSize();
		@@ -473,6 +485,9 @@ std::optional<DepositionLaserModule::PhotonHit> DepositionLaserModule::track(con
		std::vector<std::pair<std::shared_ptr<Detector>, std::pair<double, double>>> intersection_segments;

		for(auto& detector : detectors) {
		if(detector->getModel()->getSensorMaterial() != SensorMaterial::SILICON && !is_user_optics_) {
		continue;
		}
		auto intersection = intersect_with_sensor(detector, position, direction);
		if(intersection) {
		intersection_segments.emplace_back(std::make_pair(detector, intersection.value()));

src/modules/DepositionLaser/DepositionLaserModule.hpp

+1 −0

Original line number	Diff line number	Diff line
		@@ -133,6 +133,7 @@ namespace allpix {
		double absorption_length_{0.};
		double refractive_index_{0.};
		double pulse_duration_;
		bool is_user_optics_;

		// Histograms
		bool output_plots_;

src/modules/DepositionLaser/README.md

+5 −3

Original line number	Diff line number	Diff line
		@@ -11,12 +11,13 @@ module_output: "DepositedCharge, MCParticle"
		## Description

		This deposition generator is mostly intended for simulations of laser-TCT experiments.
		It would generate charge, deposited by absorption of a laser pulse in silicon bulk.
		It generates charge, deposited by absorption of a laser pulse in detector bulk.
		This module is not dependent on Geant4. Instead, it implements tracking algorithms and simulations of corresponding physical phenomena by its own, using internal Allpix geometry.

		Current implementation assumes that the laser pulse is a bunch of point-like photons, each traveling in a straight line. A lookup table \[[@optical_properties]\] is used to determine absorption and refraction coefficients for a given wavelength.
		Current implementation assumes that the laser pulse is a bunch of point-like photons, each traveling in a straight line. A lookup table \[[@optical_properties]\] is used to determine absorption and refraction coefficients in silicon for a given wavelength.
		The only supported sensor material is silicon, unless optical properties are explicitly set (see Parameters).

		Multiple photons are produced in a one event, thus a single event models a single laser pulse.
		Multiple photons are produced in one event, thus a single event models a single laser pulse.


		Tracking features:
		@@ -60,6 +61,7 @@ As a result, this module yields `DepositedCharge` instances for each detector, w
		* `focal_distance`: needs to be specified for `converging` beam. This distance is as it would be in air. In silicon, beam shape will effectively stretch along its direction due to refraction and the actual focus will be further away from the source.
		* `beam_convergence_angle`: max angle between tracks and `beam_direction`. Needs to be specified for a `converging` beam.
		* `output_plots`: if set `true`, this module will produce histograms to monitor beam shape and also 3D distributions of charges, deposited in each detector. Histograms would look sensible even for one-event runs. Defaults to `false`.
		* `absorption_length` and `refractive_index`: if both are specified, they override corresponding values from the lookup table. This also allows use of sensor materials other than silicon.

		## Usage
		A simulation pipeline to build an analog detector response would include `DepositionLaser`, `TransientPropagation` and `PulseTransfer`.

src/modules/DepositionLaser/tests/05_user_optics.conf

0 → 100644

+23 −0

Original line number	Diff line number	Diff line
		# SPDX-FileCopyrightText: 2023 CERN and the Allpix Squared authors
		# SPDX-License-Identifier: MIT

		#DESC tests reading of physical constants from the datafile

		[Allpix]
		detectors_file = "geometry_basic_diamond.conf"
		number_of_events = 1
		multithreading = false

		[DepositionLaser]
		log_level = "DEBUG"
		beam_geometry = "cylindrical"
		number_of_photons = 1
		source_position = 0 0 0
		beam_direction = 0 0 1
		wavelength = 1064nm
		absorption_length = 1mm
		refractive_index = 2.5


		#PASS Wavelength = 1064nm, absorption length: 1mm, refractive index: 2.5
		#FAIL Detector d1 has unsupported material and will be ignored

src/modules/DepositionLaser/tests/cube_1mm_diamond.conf

0 → 100644

+10 −0

Original line number	Diff line number	Diff line
		# SPDX-FileCopyrightText: 2023 CERN and the Allpix Squared authors
		# SPDX-License-Identifier: MIT

		type = "monolithic"
		geometry = "pixel"
		sensor_material = "diamond"

		number_of_pixels = 1 1
		pixel_size = 1mm 1mm
		sensor_thickness = 500um