- Summer 2020
Syllabus Description:
PHYS427 Course Description
Summer 2021
Applications of Physics (Low temperature physics)
Name of the Instructor: Subramanian Ramachandran, PhD
Number of credits: 3
In this course, we will discuss the physics and thermodynamics of mechanisms involved in the realization of cryogenic temperatures down to nK. The focus will be on closed cycle refrigerators including pulse tube and Gifford-McMahon refrigerators. Topics to be studied will include dilution refrigeration, and adiabatic demagnetization refrigeration. Importance of high vacuum and radiation shields to mitigate parasitic heat transfer will be emphasized. Subject to availability of time, types of temperature measurement sensors and circuits used for low temperature applications, the phenomenon of superconductivity and application of cryogenic calorimetry to the study of various phase transitions will be included. Throughout the course the underlying physics will be discussed alongside the engineering considerations.
Pre-requisites:
Physics 224 (Thermal Physics) and 225 (Intro to Quantum) with a minimum grade of 2.0 in each are the required prerequisites for this course. Please contact the instructor if you have questions at:
ramacs@uw.edu
Prescribed text: Matter and Methods at Low Temperatures 3rd edition, Frank Pobell, Springer Publications, ISBN: 10-3-540-46356-9.
Contact Information:
Instructor: Subramanian Ramachandran, ramacs@uw.edu
Detailed Course Syllabus:
PHYS 427 _Applphy_Sum2021_course_syllabus.pdf
Weekly Schedule:
|
Week |
Date |
Topic |
Read |
HW |
|
1 |
6/22 |
Introduction, Properties of LH2 |
Pobell 2.2 |
HW 1 assigned |
|
|
6/24 |
LH2 and LHe (Quiz 1) |
Pobell 2.3 |
|
|
2 |
6/29 |
LHe (Quiz 2) |
Pobell 2.3 |
|
|
|
7/1 |
Discussion of relevant thermal, electrical, and magnetic properties |
Pobell 3 |
Hw 1 due, HW 2 assigned |
|
3 |
7/6 |
Discussion of relevant thermal, electrical and magnetic properties (Quiz 3) |
Pobell 3 |
|
|
|
7/8 |
Thermal Contact and Thermal Isolation; He4 cryostat, He4 cryostat |
Pobell 4.1 to 4.3 , 5.2 |
HW 3 assigned |
|
4 |
7/13 |
Closed Cycle refrigerators (Quiz 4) |
Notes, Pobell 5.3 |
HW2 due,
|
|
|
7/15 |
Closed Cycle refrigerators Review; Exam online |
Notes |
|
|
5 |
7/20 |
Helium 3 cryostat (Quiz 5) |
Pobell 6.1 and 6.2 |
HW 3 due, HW 4 assigned |
|
7/22 |
3He-4He dilution refrigerator; phase diagram (Quiz 6) |
Pobell 7.1-7.3 |
|
|
|
6 |
7/27 |
3He-4He dilution refrigerator; building blocks |
Pobell 7.3, 7.4 |
HW 4 due HW 5 assigned |
|
|
7/29 |
Pomeranchuck cooling (Quiz 7) |
Pobell 8.1-8.3 |
|
|
7 |
8/3 |
Refrigeration by adiabatic demagnetization of paramagnetic salt (Quiz 8) |
Pobell 9.1- 9.4 |
HW 5 due, HW 6 assigned |
|
8/5 |
Adiabatic nuclear demagnetization Review, Exam online |
Pobell 10.1-10.3 |
|
|
|
8 |
8/10 |
Adiabatic nuclear demagnetization – heat load and heat leak (Quiz 9)
|
Pobell 10.4-10.5 |
HW 6 due, HW 7 assigned |
|
|
8/12 |
Nuclear refrigerants, hyperfine enhanced nuclear refrigeration, nuclear demagnetization refrigerator |
Pobell 10.6-10.8 |
|
|
9 |
8/17 |
Low temperature thermometry (Quiz 10) |
Pobell 12.1-12.3 |
HW 7 due |
|
|
8/19 |
Review, Exam online |
|
|