Physics 128 – Senior Lab – Winter 2026

Meeting time: MW and TTh 1-5+ in 3223 Broida (you are expected to show up to every class with the exceptions of being sick or a test conflict). See TA’s for conflicts.

Prof Philip Lubin

Office – 2015 C Broida

Class contact email address – lubin@ucsb.edu

TA’s:

June Muhlenkamp jam75@ucsb.edu

Vivek Dhande vivekdhande@ucsb.edu

Mara Niesyt mniesyt@ucsb.edu

Yu-Tse Lee yutselee@ucsb.edu

Office Hours: TBD

Lab managers: Anatoliy Dovbnya (anatoliydovbnya@ucsb.edu)

Course structure

Physics 128 is quite different than the classes and labs you have had so far. Much of it is based around becoming familiar with classic modern physics experiments and part of it is learning to do research yourself and with a small group. You will need to study and understand statistical methods of data analysis. You will have to understand the equipment you’re given, figure out what procedures to follow and what data to collect, actually collect data, analyze the data, and present it in a scientific manner. The focus of the class is NOT pencil-and-paper physics problems. Rather, the focus is:

General lab conduct and skills; how do you walk up to an unknown piece of equipment and make it do something useful? How do you get a table of numbers out of your notebook and into a publishable graph or figure?
Understanding real-world data; what’s the relationship between a “physics number” (an index of refraction, or the speed of light, or the mass of an electron), our error bar on such a number, and the procedure you’re using to measure it? This is sometimes called “statistics”, but actual statistics is only part of the story.
General science-world conduct. You have to work with a partner, follow lab safety practices, keep an good lab notebook, write concise and sensible reports and papers.
All your lab work must be kept in electronic form though I also recommend a handwritten lab book.
In addition to the required lab. highly motivated students can also work on independent projects with the permission and coordination of the lab faculty member (Philip Lubin).

The collection of lab experiments offered can be found here.

You will do 4 of these in addition to the portable gamma ray spectrometer lab (first two weeks).

https://ilg.physics.ucsb.edu/Courses/Upper/128A/index.html

Course intro document

Senior Lab Intro – 128-W26

Class Syllabus (see also Canvas)

Senior Lab Syllabus

Example Lab Writeup (see also Canvas)

example_lab_report

Data Reduction and Error Analysis references

Data Reduction and Error Analysis -Bevington – 3rd ed

Taylor-An Introduction to Error Analysis – 2nd ed 1997

First two weeks – Radiation Physics and Gamma Ray Spectroscopy (GRS)

The first two weeks of the course will be a unique individual study of radiation physics and statistical analysis using a portable gamma ray spectrometer and radiation Geiger counter.

Our world is surrounded by sources of radioactivity from cosmic ray bombardment to radioactivity in the food we eat and the air we breathe to residual radiation from above ground nuclear weapons testing.

You are radioactive as well, as is the building etc. See my Phys 150 class for much more detail.

Gamma spectrometer we will be using – works with your smart phone and Windows computer. Please read up on how it works, software, cyberspace community.

The GRS unit you will be using is: https://www.radiacode.com/products/radiacode-110

You will find the software for your Android and iPhone as well as Windows computers and lots of other info there.

Software: https://www.radiacode.com/software

Downloads: https://www.radiacode.com/downloads

Gamma spectrum isotope library (also see much more below): https://www.radiacode.com/spectrum-isotopes-library

See Cyberspace Link for Manuals and online community:

Online community: https://www.radiacode.com/community

You will be borrowing this unit and will be responsible for it.

Be very careful not to drop it.

Class Lectures on Radiation

Radiation and Radiological effects

Radiation Interactions in Matter – Bigelow – Chap 5

NucRad – Radiation Interactions in Matter – Roberta Bigelow – Chap 5

Medical Physics Radiology ABR Exam 2024

Radiation Biology – 2024 – Chapter1

Radiation Biology – 2024 – Chapter4

Radiation Biology – 2024 – Chapter5

Radiation Biology – 2024 – Chapter6

Radiation Biology – 2024 – Chapter7

Radiation Biology – 2024 – Chapter8

Radiation Biology – 2024 – Chapter9

Radiation Biology – 2024 – Chapter10

Ra diation Biology – 2024 – Chapter11

Radiation Biology – 2024 – Chapter12

Radiation Biology – 2024 – Chapter13

Gamma Ray Spectroscopy

https://en.wikipedia.org/wiki/Gamma_spectroscopy

“Gamma ray spectra show unique energy “fingerprints” (peaks) for different isotopes, created by detectors measuring gamma photons; key isotopes like Cobalt-60 (⁶⁰Co) have strong 1.17 & 1.33 MeV peaks, Cesium-137 (¹³⁷Cs) shows a prominent 662 keV peak, Sodium-22 (²²Na) has 511 keV (annihilation) and 1.27 MeV lines, while natural samples (Uranium/Thorium) reveal complex decay chains like ²¹⁴Pb/²¹⁴Bi at ~352 keV, allowing precise identification of radioactive materials in nuclear forensics, environmental monitoring, and nuclear medicine.”

https://www.nrc.gov/docs/ml1122/ml11229a699.pdf

https://www.gammaspectacular.com/blue/gamma-spectra

https://www.sciencedirect.com/science/article/pii/S0969806X25001847

Nuclide identification of radioactive sources from gamma spectra using artificial neural networks – Barradas et al 2025

National Nuclear Data Center

https://www.nndc.bnl.gov/

Nuclear Wallet Cards

https://www.nndc.bnl.gov/walletcards/search.html

Nuclear Wallet Cards-2023-10

Nuclear Wallet Cards for Homeland Security

https://www.nndc.bnl.gov/walletcards/radioactive-2004.html

Nuclear Wallet Cards for Radioactive Nuclei -2004

Non Proliferation Treaty Verification – Isotopic Analysis of Plutonium – LANL

https://cdn.lanl.gov/files/app-to-isotopic-analysis-using-fram_06e9e.pdf

LANL Non Proliferation Treaty Verification from Isotopic Analysis using FRAM Software

Gamma Ray Spectra from Thermal Neutron Capture – Neill et al 1963 – DTIC

https://apps.dtic.mil/sti/tr/pdf/AD0428231.pdf

Measurement of Gamma-Ray Spectra from Thermal Neutron Capture – MIT – Neill et al 1963

Table of Gamma Rays

https://atom.kaeri.re.kr/old/gamrays.html

Practical Gamma Ray Spectroscopy – Gilmore 2008 – PDF Book – 390 pages – Excellent

Practical-gamma-ray-Spectroscopy- Gordon Gilmore – 2008

CsI crystal with solid state photomultiplier:

https://www.radiacode.com/products/radiacode-110

Some background reading:

My class on nuclear weapons with hundreds of links including radiological links and searching for fissile materials in nuclear WMD’s:

Physics 150 – Nuclear Weapons – Physics, Policy, Proliferation – Fall 2025

Physics 150 – Nuclear Weapons – Physics, Policy, Proliferation – Fall 2025

Oak Ridge Museum of Radiation and Radioactivity

https://www.orau.org/health-physics-training/museum.html

https://periodictable.com/Elements/Source-oakridge/index.html

Manhattan Project Health Physics and Nuclear Medicine

Health Physics & Nuclear Medicine During the Manhattan Project

Neutron Detection

Gallium Nitride use in detecting neutrons via neutron absorption on Nitrogen and subsequent gamma emission via 14N(n, p)

Neutron detection performance of Gallium Nitride (GaN) based semiconductors (used in LED’s) – Zhou et al Nature 2019

Scientific Reports volume 9, Article number: 17551 (2019) – See neutron cross sections in various materials

Neutron detection performance of gallium nitride based semiconductors – Nature – Zhou et al 2019

Next Generation Neutron Detection using Li-6 Glass Scintillator – Favalli et al 2025

Next-generation neutron detection using a 6Li glass scintillator composite – Favalli et al 2025

Practical Gamma Ray Spectroscopy – Gilmore 2008 – PDF Book

https://nna1989.wordpress.com/wp-content/uploads/2015/05/gordon-gilmore-practical-gamma-ray-spectroscopy-2008.pdfhttps://ahf.nuclearmuseum.org/ahf/history/health-physics-nuclear-medicine-during-manhattan-project/

Practical-gamma-ray-Spectroscopy- Gordon Gilmore – 2008

Online and Windows Radiation Propagation Program includes isotopes and shielding – Rad Pro

For Online version use Online Calculators Tab

http://www.radprocalculator.com/RadProDownloads.aspx

Events and Links

Physics Department Colloquium: Tuesdays at 4:00 in Broida 1640

Astro Colloquium: Wednesdays at 4:00 in Broida 3302

Astro Lunch Colloquium: Fridays at 12:00 in Broida 3302

LCOGT Colloq usually Thur 4-5 at the LCOGT facility – BUT van to colloq leaves from Physics lot at 3:45 and you must sign up to get room on the van. Van returns you to Broida after talk.

Physics Dept Colloq schedule

Astro web event schedule

LCOGT Colloq Schedule (must sign up for van)

KITP Schedule

LCOGT – Las Cumbres Observatory

Sedgwick LCOGT Observatory

Sedgwick Weather log