Address: Bldg 510e, Brookhaven National Laboratory, Upton, NY 11973
Address for Fedex: Department of Physics, Bldg 510, Brookhaven National Laboratory, Upton, NY 11973
Phone: 631-344-3327, fax: 631-344-4741
email: diwan at bnl.gov or milind.diwan at gmail.com
Title: Distinguished Scientist
Curriculum Vitae CV
Research Summary, Publications RS
With collborators, I initiated, proposed, and organized the ambitious long-baseline neutrino program in the US based on the high intensity Fermilab Main Injector and a massive underground detector (LBNF/DUNE) at the Sanford Underground Research Facility at the former Homestake gold-mine in South Dakota. The plan I developed and promoted is now the highest priority fundamental science project in the US (named Long-baseline Neutrino Facility and Deep Underground Neutrino Experiment(LBNF/DUNE)). It is also likely to be the largest international project in the US.
Paper that provides details of the analysis Phys.Rev.D68:012002
This is the preprint that provides justification for the configuration of LBNF/DUNE with Fermilab as the source. The Case for a Super Neutrino Beam
This is the link to the national study that I co-led and authored; this report formed the basis for the LBNF/DUNE project approval.
The Large Hadron Collider at CERN collides protons with center of mass energy of 14 tera-electron-volts (7 TeV on 7 TeV). These collisions produce a large number of particles that decay as they fly away from the collision point. It turns out that the decays in forward direction of the LHC produce a big flux of neutrinos. We have investigated this flux and energy spectrum and possible applications for fundamental physics.
Article on neutrinos for children. This was reviewed by children.
It was a wonderful experience to do this project with Karen McNulty Walsh.
Annual reviews article on neutrino physics with focus on experimental evolution on oscillations
Annual Reviews Long Baseline Neutrinos
Another link to same review Experiments with solar, atmospheric, reactor, and accelerator neutrinos have resulted in a coherent picture of neutrino masses and mixings of the three known flavor states. We summarize the current best knowledge of neutrino parameters and phenomenology, with a focus on the evolution of the experimental technique.
Link to the conference indico site: TIPP2023
Milind Diwan (BNL)
Proceedings write up.
Proceedings Paper
You will find that I attempt to be as general as possible when discussing experimental techniques. The lectures are academic and will contain original work that connects textbook material to actual application. I have also supplied notebooks and spreadsheets to make realistic calculations.
Please feel free to use these, but I will certainly appreciate any acknowledgement.
These set of lectures are at a level of senior undergraduate to graduate students. They are 1) a brief introduction to natural and man-made neutrino sources, 2) a survey of neutrino interactions, basic formulas for calculating event rates, and cross sections, 3) a summary of physics of oscillations and results from leading experiments. and a brief aside on the index of refraction of neutrinos Nov. 29, 2018. 4) (Feb 16, 2023) I have added a Mathematica notebook for calculating oscillation probabilities following Ohlsson and Snellman (J. Math Phys. 41, No 5 May 2000)
Neutrino Sources KEY
Some basics of reactor neutrinos. These slides were for undergraduate students.
Mathematica notebooks
Some data files that need to be read into above notebooks. Please note the XCCreactor.dat cross section tabulation is not very good at low energies, but it is included for comparison with the correct one from Vogel and Beacom.
Notebooks in PDF form
In this section, I will provide materials to understand basics of radiation detectors. This includes
notes in the format of slides, spreadsheets for calculations, and mathematica notebooks.
Neutrino Detectors 1
Neutrino Detectors 2
A thorough analysis is provided on how to calculate the gain, high voltage dependence, and pulse shape from a PMT.
Many of the pathologies that are encountered due to poor choices are provided along with techniques for understanding the pulses.
An introduction to cable transmission is provided with techniques that could be used for simulation of the effects of the cable.
Photomultiplier tubes and coaxial cables PDF
Photomultiplier tubes and coaxial cables KEY
Notebook to make the plots in the above slides NB
Notebook for calculation of cable dispersion/attenuation NB
Photomultiplier divider calculation example XLSM
Often photomultipliers (as well as other detectors) are utilized with capacitive coupling. Primary
motivation for this it to provide the bias voltage for the detector on the same cable that
carries the signal. The capacitive coupling is needed to separate the fast signal from the high voltage.
This however leads to some complications which includes a bipolar pulse. The treatment of all this is well known in
the community, nevertheless here I have performed a rather detailed analysis of the pulse shape and its consequences.
First, we will just do a brute force analysis of bipolar pulse shapes and how to analyze them. It is not clever or
original. It is a relatively simple issue: for any falling pulse, if you differentiate it, the output will become negative.
We have to make this negative part small and spread it out over a long time so that the pulse retains the unipolar nature as
much as possible.
Photomultiplier with AC coupling PDF
Photomultiplier with AC coupling KEY
Notebook to make some of the plots for AC coupling
There is a much better way to fix the problem of bipolar pulses with significant overshoot. The idea is to create a
situation where the pole created by the differentiating circuit due to the decoupling capacitor is cancelled by a
zero that is introduced by adding the same valued capacitor on the PMT side.
Pole Zero cancellation for PMTs PDF
Photomultiplier spectrum analysis PDF
Photomultiplier spectrum analysis KEY
I have written a paper describing the PMT spectrum. This should be used together with the slides above. The mathematica code that generates the plots in the paper along with the data is provided in a link below.
Photomultiplier PAPER PDF
Also see
1909.05373
PMT spectrum code and data TAR-file
In this subsection we will explore the time resolution. The first limitation is from the statistics of
photon detection and the time distribution of scintillation photons. In these
set of notes, we calculate the expected resolution if we measure the time of the first photon from a light pulse.
We then calculate the effect of Poisson fluctuations on the number of detected photons. Interestingly, we end up
with a time resolution that has long tails, reminiscent of data from scintillation counters.
PMT first photon resolution PDF
PMT first photon resolution KEY
PMT charge, time, counting statistics PDF
Seminar direct link to video MP4
Neutrino Sources PDF
Neutrino Interactions KEY
Neutrino Interactions PDF
Neutrino Oscillations KEY
Neutrino Oscillations PDF
Neutrino Oscillation Calculator Math-notebook NB
Neutrino Index of Refraction PDF
Reactor Neutrino Calculations
I will provide some introductory material and mathematica notebooks for performing reactor neutrino calculations.
The idea here is not to perform extremely precise calculations, but to provide enough tools to understand the physics. The notebooks should be very useful for a graduate level course. If you use them, I will certainly appreciate acknowledgement.
Reactor Basics PDF
Inverse Beta Decay Cross Section
Reactor Spectrum Parameterization
Event Rates and Oscillations
Reactor Neutrino Spectrum
IBD crosssection
Daya Bay based detected spectrum (not normalized)
Inverse Beta Decay Cross Section
Reactor Spectrum Parameterization
Event Rates and Oscillations
Solar Calculations
Not done yet.
Detector Techniques
Basics of Neutrino Detectors
Neutrino Detectors 1 PDF
Neutrino Detectors 2 PDF
Special section on photomultiplier tubes
In the three lectures and associated materials below, I provide the basic tools for
understanding photomultiplier tubes and their applications for particle physics. The slides are
focused on what is needed for scientific analysis of experimental data.
The manuals and guides from the photomultiplier vendors
such as Hamamatsu and Electron-tubes are excellent and should be consulted on various technical details.
Photomultiplier Tubes and Coaxial cables
Photomultipliers with AC coupling readout
Pole-zero analysis for PMTs
Photomultiplier charge spectrum and absolute calibration
In these set of slides, I have derived a complete, with very few assumptions or approximations,
description of the expected charge spectrum from a typical photomultiplier tube. The resulting
formula can be used for fitting the charge spectrum from a phototube subjected to a constant
low intensity light source. If the source is sufficiently low intensity, it is possible to separate
the mean intensity of photons from the gain and the variance on the gain. This subject has been
treated in the literature in the past, but I found the treatment incomplete.
Arxiv.org paper on PMT charge spectrum
Limitations on time resolution from Photomultipliers
Comprehensive summary of charge and time statistics
A summary of the charge and time statistics is provided. A brief comment on counting statistics is also made.
For detailed derivations, please check the material above. A recorded
video of a seminar is also here.
Liquid Scintillators
In this section, I will cover the basics of organic liquid scintillators. I will also contrast them with noble liquids.
The first section of the talk will be pedagogical on the mechanics of light production in such materials, second section
will provide a review of applications for particle and nuclear physics, and last will be current R and D as well as some speculations
on future directions that might be fruitful. (This is based on a seminar that I gave at TIPP2023 conference in South Africa). A 6 page narrative that covers the basics from the talk is also attached.
Slides
Video
Proceedings Paper
Our group has been assembling an extensive library of properties for liquid argon as detector material. The link is provided here. The webpage is interactive.
This is a link to a Mathematica notebook that has a library of common detector materials, and modules for calculating basics of energy loss in those materials. The notebook covers 1) average dEdx, 2) restricted energy loss, 3) calculations with or without density correction, 4) basic kinematic quantities in energy loss, 4) most probable energy loss, 5) energy loss distribution in thin material, 6) simulation of energy loss in thin material, 7) Particle range in materials.
At the start of the notebook, you have to select one of the many materials. If you want to add a material, please follow the format and add it. In the future, I intend to add several items: range straggling calculation, simple simulation of low energy scattering, calculation for showering particles. Further to do list: simple formulas for muon enery loss including showering at high energies. Basic simulation of electromagnetic showers.
Science requirements for signal and noise in liquid argon TPC
This covers topics in analysis of linear systems. It should be a basic reference for a unified treatment of
noise and Fourier analysis. Some of my derivations are unusual.
Detectors Signals and Noise PDF
The subject of random noise is very important and deep; In these two lectures I present some of the mathematical tools.
Basic Mathematics of Random Noise 1 PDF
Basic Mathematics of Random Noise 2 PDF
The subject of probability and statistics is vast and varied. There are also connections between subtopics that are not obvious and sometimes mysterious because of the long history. My own interest is not the mathematics but its application to detector analysis. In the following, I will build a library of material for such purpose.
Fisher information is a way of measuring the amount of information that an observable X carries about an unknown parameter (t) on which the
probability of the random variable X depends. These are simplified notes on this theory. These are meant to reduce the heavy mathematics that usually comes with some of the derivations.
Fisher information and Cramer Rao lower bound PDF
This is an example of using characteristics functions to obtain combined probability density functions. This
example corresponds to detector pulses that are composed of a finite number of counts.
Detector Pulses and Compound Poisson PDF
Binomal, Urn models are fundamental to any analysis for detectors. There is a lot of confusion in the detector physics literature; mainly because of inconsistent nomenclature. This is an attempt to produce notes that are useful for the practicing experimental physicists.
Binomial, Urn models, and Polya distribution
In the following we examine the exponentially modified Gaussian and the Log-normal distributions. We will derive these distributions, and compare their various properties. We show that in most practical situations either of these can be used. We also provide references.
Exponentially modified Gaussian and the log-normal distributions PDF
Exponentially modified Gaussian and the log-normal distributions KEY
Detector pulses have similarities to the Gamma PDF (for good reasons), and so it seems natural to try convoluting it with the normal for use in modeling and fits. While I was doing this, I found a very nice solution on stack-exchange (by Mr. Huber). I will add to this over time.
Gamma Modified Gaussian PDF
We examine the logistic PDF and show an application in pulse fitting to obtain the precise time and total charge in the presence of noise. The logistic PDF is an extraordinarily useful tool which appears to be underutilized. This PDF is fundamental to schemes of classification. I will discuss this separately (still in the works).
Logistic distribution and application to pulse fitting
A random sequence in time is a fundamental entity in physics (and all of science and even the stock market.). A random process is a collection of random variables indexed by time. The simplest example is an indicator function or just 1 or 0. The random number can also be a real number such as temperature. The time index can be continuous or discrete.
A random process is also known as a random function of time. A particular outcome of an experiment is called a "sample function" or "sample path". This is a vast subject. We will collect some useful items from the literature here.
Here basic tools for analysis of spectra are developed.
Covariance and Spectrum analysis
Covariance and Spectrum analysis PDF
Here are some basics for mechanical vibration analysis. I wrote this lecture to provide basic understanding for physicists who needed to move large objects. These have many common features with the mathematics of noise
and similar tools from electrical analysis.
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Mechanical Vibration Analysis KEY
Mechanical Vibration Analysis PDF
Notebook on 2 body vibration simulation NB
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These set of notes concern analysis of failure in systems. This is a very important and complex topic in engineering. Engineers and material scientists have developed decades (centuries) of experience in why things fail and how they fail. There is a wide ranging discussion on various statistical methods for analysis of such failures including certificates for online courses. My notes are specifically intended to introduce the subject to experimental physicists who have only a passing understanding of these issues. I have included some unpublished data on pressure testing of photomutipliers from BNL. I must thank Prof. Lacourse and Prof. Sundaram from Alfred university for giving me a tutorial on this subject.
Reliability of Failure Analysis PDF
MINOS: Main Injector Neutrino Oscillations
click here
The Joint FNAL-BNL study on long baseline neutrinos
click here
The Daya Bay project
click here
Sanford Underground Research Facility
click here
The Long Baseline Neutrino Experiment
LBNE
which has been transformed into
DUNE
PROSPECT project
prospect
ICARUS experiment at Fermilab
ICARUS
AIT/NEO project in Boulby
AIT/NEO
Projects
E949: Rare decays of kaons; Kplus to piplus neutrino and anti-neutrino
click here
Publications
click here
Technical Notes
Search under
OSTI
Computing at BNL physics and on SDCC cluster
Amazing Books.
Field Guide to Continuous PDFs by G. E. Crooks
Bateman Manuscripts on Integral Transforms
Some of this material was produced for the African School of Physics in 2018. It was presented in Namibia to a group of 60 high school teachers using Raspberry PIs. Each unit has a Mathematica notebook and a PDF. Some of the units have multiple files.
How to do basic mechanics (high school level)
Electricity and Magnetism (high school level)
Basics of probability and statistics
Fractals, Marcov chains, and a puzzle
I keep developing new stuff all the time. I will eventually collect it into a separate section on this webpage.
This is a way to visualize Fourier transforms as projections of circles added together. It is well known idea and there are many You Tube videos on this. Here I have provided a basic Mathematica structure for those who want to play with this.
Fourier Transform Visualization NB
Last modified: (2025-11-20 17:28:52 EST)